One species über alles - MorrisCourse.com€¦ · power lines crisscross the land. Dams impede...

Environmental Biology © 2019 by Tom Morris Ch. 5: Human-Caused Change 1

5 Human-Caused Change

One species über alles

NASA composite image showing the planet at night. The spreading presence and influence of humans is apparent.

Human use of the land

At the moment and for the previous 10,000 years, Homo sapiens is and has been the most dominating species on Earth. Humans have expressed their growing power by transforming the Earth’s natural landscapes. Forests have been cleared to become farm land or grazing land. Prairies once filled with dozens of species of native grasses have been replaced with enormous monocultures of wheat or corn or rice. A growing meshwork of distribution infrastructure now connects nodes of production with nodes of trade, in the form of highways, railroads, and communications. Pipelines and power lines crisscross the land. Dams impede rivers. Urban centers intensify and the tendrils of suburban sprawl creep ever outward. To supply this busy place, there is growing consumption of the Earth’s limited resources. And there is unfortunate spoiling of the lovely planet of our inheritance.

The histories and the continuing stories of this transformation are vast. This chapter attempts to summarize the key components of human-

environment interactions, including the bad things we do, and including the good things we do to reduce our impacts on the environment.

Farming, Agriculture

Once humans understood the operations of plants, and the life cycle of plants, they developed the technologies of gardening and farming – to grow their own food. Farming and agriculture developed independently on all continents as early as 10,000 years ago. The origins of agriculture in different places may have been driven by different circumstances. But all produced the ultimate transformation of the land from a natural landscape to one dedicated to growing food for humans.

2 Environmental Biology © 2019 by Tom Morris Ch. 5. Human-Caused Change

Wheat fields in England.

Before the invention of farming, humans worldwide made their livings by wandering, hunting and gathering. As humans ceased their wandering ways in order to tend their crops, they developed the techniques of animal domestication – keeping goats, sheep and cattle for milk, leather hides, fiber, meat and fat. So, humans, crops and their domesticated animals settled down and intensified their exploitation of their local environments.

Homes, settlements, markets and trade centers – towns and cities

Once settled, people began to develop sturdy housing, giving up the light tents they might have transported from place-to-place in their wanderings. They harvested trees from their surroundings for construction timbers. Trees and woody plants continued to be used as a source of firewood for cooking and heating.

Made possible by agricultural success, human populations began to persist and expand in certain pockets in which the farm land was productive, especially in the fertile soils adjacent to rivers. More and more of the land was taken into cultivation. And more of the land was used for housing and animal domestication.

Agricultural surpluses produced opportunities for trading, so trade centers evolved and the marketplace was born. People not directly involved with food production would trade supplies, tools clothing, or labor for food. Others set up shops and began to broker trades between the producers themselves and others. The trade center became a town. As it continued to grow, the town ultimately

became a city. And as growth progressed, so did the transformation of the surrounding landscape.

Open marketplace in Senegal, Africa.

Transportation – city streets, highways, railroads and railroad stations, seaports, airports

Agricultural productivity spawned an agricultural economy, and that economy flourished and spread with the transformation of footpaths into roads. Carts pulled by domesticated beasts of burden transported goods from production points to marketplaces, and marketplace-to-marketplace (city-to-city). The financial rewards of speedy transport inspired constant improvement efforts. Today’s network of roads, highways, freeways, railroads, stations, seaports and airports represents a fundamental and essential component of today’s teeming world economy.

Freeway interchange in southern California. ©2013 Google

As more and more goods are transported, and as more and more people must travel from home to jobs or to shop, the components in this network


have gotten larger. In major urban centers, freeways are 20 lanes across. Small highways are more numerous and are four lanes across. International airports have six runways. Seaports have several miles of commercial docks where container ships line up to offload their cargo. And freight trains a mile long haul these goods cross-country.

The main point is that as cities have grown, so has the transportation infrastructure. And these transportation components occupy substantial amounts of land space.

Timber and wood harvesting. Deforestation

Wood is a very valuable resource and commodity. Humans have perfected the technologies for rapidly clear-cutting a forest, and milling the logs (tree trunks) into lumber. Or many of the logs are softened by floating them in odiferous pools of stagnant water later to be ground into pulp and pressed into sheets of paper.

Georgia Pacific lumber mill, Eureka, CA.

Mining and fossil fuel extraction – minerals, oil patches, coal mines

In addition to gathering food from farms and wood from forests, humans have torn deep into the earth for rocks and minerals. Granite, limestone, marble, and shale are favorite building materials for the construction of all sorts of buildings. Manufactured building materials such as brick and cement are made with clay, sand, limestone and gypsum.

Humans dig large open pits to get at metal-bearing ores, gravel, salt, and coal. Or, we burrow deep underground creating labyrinths of tunnels in our

never-ending quest for the mineral goods, precious metals and coveted gem stones embedded beneath.

Udachnaya Diamond Mine, Russia.

Sometimes we resort to sucking stuff out of the earth like soda through a straw. Prospectors construct mighty industrial platforms to drill deep down hoping to tap pools of petroleum and natural gas. And then pepper the landscape above with rocking horse oil pumps, storage tanks, pipelines and stained soil that adorn and define the oil patch.

Energy farms – wind farms solar farms

Energy farms are a relatively recent development. Seeking safer and non-polluting forms of energy production, humans have sought to directly harness the sun and the wind – and on a large scale. New solar energy power plants consist of hundreds of acres of either mirrors (heliostats) or photovoltaic panels. And wind farms consisting of hundreds of wind turbines exist in dozens of locations around the world and many more are planned.

Gemasolar power plant, Spain.


Industrial production

Humans are a very industrious form of life. Humans engage the resources of the planet to fabricate ingenious devices large and small, assemble fabric into clothing, process agricultural products into packaged food, refine petroleum, or recycle the lot. Water treatment for cities is done on a massive industrial scale – taking water from the environment and treating it for drinking or treating wastewater prior to discharge back into the environment. Required space could be for a work bench, a shop, or a manufacturing plant.

Geely automotive assembly line, China.

Water and energy distribution – dams, reservoirs, aqueducts, pipelines, power lines

As humans have spread out across the land, they concentrated in areas that are remote from rivers and lakes. Initially, water was channeled across the land through short irrigation ditches to riverside farmland. Then to more remote villages and farms through canals and aqueducts. But during years of drought, the water stopped flowing. In response, dams were constructed to make water supplies more reliable. As a result, human development grew in arid lands, dependent upon a network of dams, aqueducts and canals. The American southwest is a classic example. The cities of Las Vegas, Phoenix, Los Angeles and San Francisco would be small towns were it not for billions of gallons of water imported from remote rivers hundreds of miles away.

Glen Canyon Dam, northern Arizona.

Solid waste generation – landfills

Using any kind of resource inevitably produces waste. Eat an orange, throw away the peel. Make a plate of noodles, throw away the package. Finish a container of milk, throw away the carton. Buy a new shirt, throw away the tags. That’s just us on a personal level. On commercial and industrial levels the quantities of solid waste are enormous. Consider a tire store that sells 100 tires a day. That’s over 30,000 tires a year. Where do all the old, worn out tires go? Or think about your grocery store. Fresh produce only stays “fresh” for a few days. If all the cantaloupes don’t sell within a few days, then out they go into the dumpster out back. If we assume about 600 grocery stores in Orange County, CA, and each store is disposing of 200 pounds of trash each day, that’s over 40 million pounds of trash a year – just from grocery stores. A big game day at the local sports stadium can produce 100 dumpsters of trash. Industrial operations like factories, large and small, also produce large amounts of solid waste. For example, a machine shop grinds metal to make a special part for a jumbo jetliner. The metal shavings and used


metal blanks are discarded afterwards. Or a kitchen-counter fabricator shapes a slab of marble to exact dimensions. The marble dust and discarded pieces have to be disposed of.

Landfill for urban solid waste in Guatemala.

Military – bases, training, war, bombs, troop movements, defoliants

Nation states generally have strong identities and support a population of citizens who identify with their country’s “way of life.” Much of that way of life is made possible by an economic system of trade structured on varying degrees of fairness and opportunity. For any given nation state (like the USA), there is great interest in securing a stable environment for commercial enterprise – within the country itself and between trading partners in other countries. History is filled with examples when thriving economic systems have been taken over by force. So nation states field militaries whose mission is to secure the country’s way of life, in particular, the normal operations of the country’s economic system. Modern day militaries sometimes extend operations beyond their borders to protect the country’s economic interests around the globe. To support such wide-ranging operations, great patches of land are used for the development of bases, airfields, naval stations, and training grounds. And when it comes to armed conflict, the field of battle can encompass thousands of square miles of land and millions of square miles of ocean.

Maxwell Air Force Base, Alabama.

Expansive human population

The number of human beings on Earth has been steadily growing since the 1300s when world population was only about 350 million. As of the year 2018, world population was estimated to be 7.6 billion. When the author of this chapter was born, world population was about 2.5 billion. So, in less than one human lifetime, world population has tripled. There are two issues of concern here: 1) the total number of people; and 2) the speed at which new people are being added. In the preceding sections, I wrote about all the different kinds of activities humans are involved with, like farming, markets, industry, transportation, resource distribution, and building settlements. As the human population increases, these activities also must increase. If they don’t, then there will be shortages and the standard of living will decrease. But in nearly all cases, efforts to provide resources for a growing human population means that more of the planet’s surface must be transformed to support specifically human kinds of activities. That means there will be less and less undisturbed space for the non-human inhabitants of Earth.


World human population through the year 2000.

Spoiling the global climate – global climate change

Before getting into the topic, I want to define a few terms so that you won’t get them confused with each other.

Greenhouse Effect

The greenhouse effect is a physical phenomenon involving a defined space and four components: 1) light; 2) infrared radiation; 3) a barrier that is transparent to light but opaque to

infrared; and 4) physical objects in the space. A greenhouse is a space defined by its glass walls and glass roof. Glass is transparent to light but opaque to infrared. Light from the sun passes through the glass (the barrier) and into the greenhouse, where it strikes objects inside, like tables and pots of plants. These objects absorb the light which is converted to heat. The objects in the greenhouse warm up. As these objects continue to get warmer and warmer, the excess heat they contain is released back into the space in the form of infrared radiation. Infrared radiation is radiant heat. This infrared passes though the space and strikes the glass. But the infrared cannot penetrate the glass. Instead, it is reflected back into the space where it is trapped. As this radiant heat cannot escape, the heat content in the space accumulates and the temperature increases. As more light enters the space, more infrared is trapped and the space

continues to heat up. A greenhouse is a simple heat trap.

Your car, parked in the sun on a warm summer day behaves the same way. Light enters through the windows, strikes the dashboard and seats, and causes them to warm up. The dashboard and seats radiate excess heat in the form of infrared. But the infrared can’t get out. So, the inside of your car gets hotter and hotter.

A planet can exhibit the same heat-trapping behavior as a greenhouse. In this model, the space is the planet’s atmosphere. The barrier is a mix of gases in the atmosphere that are transparent to light but opaque to infrared. For Earth, infrared-trapping gases are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N20). These are called “greenhouse” gases. Light from the sun passes through the planet’s atmosphere and strikes objects on the planetary surface, causing the objects to warm up. In return, the warm objects release excess heat back into the space in the form of infrared radiation. But as this infrared radiation makes its way toward outer space, it interacts with the greenhouse gases in the atmosphere, which absorb the infrared and are themselves warmed. The result is that the Earth’s atmosphere acts as a heat trap in a very similar fashion as a greenhouse. This is the planetary greenhouse effect.

Global Warming

The concept of global warming is pretty simple. It means that the average annual temperature of the planet is increasing. There are several ways this could happen. For instance, an increase in the sun’s heat output could cause global warming. Or, if the planet’s orbit was decaying rapidly, bringing it closer to the sun, that could result in global warming. If large parts of the planet became darker and absorbed more of the incoming light from the

Garden greenhouse.


sun, that could cause the planet to heat up. The planet might get warmer if a large chunk of the crust overturned revealing the planet’s hot mantle. Or if the quantity of greenhouse gases in the atmosphere significantly increased, that could trap more of the sun’s heat and warm the planet.

The point is that the expression, “global warming,” does not automatically mean “warming by increased greenhouse effect.” If a planet is getting warmer, there could be many possible reasons why. However, just to be clear, recent observed global warming has been attributed to increase greenhouse effect.

Global Climate Change.

The term, “climate,” refers to the pattern of weather over the course of a year for any given geographic location. The expression, “global climate change,” refers to changes in these weather patterns for many geographic locations around the world. Global climate change can be an outcome of the planet’s overall temperature. A cooling planet or a warming planet is likely to experience climate change on a global scale.

Taking the planet’s temperature

In recent decades, scientists determined that the global average temperature of the planet was increasing. Scientists use several methods for determining the planet’s temperature.

Direct Temperature Measurement

One method is to collect thermometer readings from a global network of weather stations. Thermometers directly measure the local ambient temperature of their surroundings. Then, scientists perform a statistical analysis of hundreds of thousands of thermometer readings from around the world. The result is a graph like the one pictured below.

Weather station instruments.

Indirect Temperature Measurement.

Scientists use satellites to estimate global temperatures by indirect methods. Instead of thermometers, satellites observe various atmospheric properties from which temperatures can be calculated. Although the methods used are very different, the results generally agree with results from ground-based thermometers.

Proxies

As an alternative to direct and indirect measurements, scientists use proxies (stand-ins) to look for evidence in the Earth’s surface environment that might indicate changes in temperature patterns. For example, the depth to permafrost is a proxy for temperature trends. Scientists measure the depth to permafrost and temperature changes at different depths in the Arctic and Antarctic permafrost. Recent studies have indicated significant warming and significantly more thawing of historical permafrost zones (Osterkamp & Jorgenson, 2009).

Scientists are studying the patterns of winter ice formation and spring thawing in lakes around the world. In general, the findings indicate that lakes are covered in ice fewer days of the year. This cited study of the Great Lakes region is an example (Mishra, Cherkauer, Bowling, & Huber, 2011).

Since the 1970s, scientists have been very interested in the behavior of glaciers worldwide. Glaciers are a bit more complicated than lakes. But in general, mountain glaciers on mid-latitude and tropical mountains have been in retreat (melting back from the lower face). For example, a recent study by a large team of scientists reports that glaciers in the Andes Mountains of South America have been retreating at an alarming rate (Rabatel, et al., 2013).


Taken together, thermometer data, satellite data and proxy studies point to one conclusion: planet Earth is now experiencing rapid global warming. The below image illustrates this finding.

The base period for comparison is an average of global temperatures from 1951-1980. Based on this comparison, the average global temperature today is about 1.0° C higher than the late 1800s / early 1900s; and about 0.8° C higher than the base period (1951-1980).

But this warming has not been evenly spread around the globe. It has been patchy. Some places getting warmer faster than others. The below map shows the pattern of warming across the planet.

This drawing represents the recent warming anomaly as of 2017. The base period for comparison is an average of global temperatures from 1951-1980. According to this map, warming has been greatest in the high northern latitudes, including the Arctic and the northern regions of North America and Asia. Significant warming also has occurred in northern Africa and along the Antarctic Peninsula. With the exception of the

eastern Pacific Ocean and the Antarctic Ocean, oceans have experienced generally uniform warming with moderate increases in average temperatures.

But how does this recent warming trend compare with long-term temperature patterns? Direct measurements of the Earth’s temperature go back only to about 1880. That’s not a long enough. Scientists have discovered that the Earth leaves records of past climates and past atmospheres in a variety of ways.

For example, scientists take cores deep into mountain glaciers or on the icecaps of Antarctica and Greenland. The ice in these locations comes from snow that is deposited year after year. Although it is almost always below freezing in these locations, most of the snow never melts. Later layers of snow compress the underlying old layers, turning it to ice. The result is a sequence of ice layers with each layer representing an episode in time. The deeper the layer, the older the ice.

Determining the age of each layer can be done in a variety of ways. One method is to count annual layers. At the time of ice formation, the top inch or so melts slightly during summer, and then is refrozen in autumn. This melting-refreezing process produces a thin and recognizable layer in the ice. Scientists use this layer as annual timestamp. Scientists count these layers as you would count tree rings.

Ice reveals information on the mix of gases in ancient atmospheres, and ancient global temperatures.

Ice is a kind of archive of past climate and past atmospheres. By examining the relative ratios of two different isotopes of oxygen atoms (O16 and O18) in the water molecules that make up the ice, scientists can estimate the Earth’s average temperature.

When ice forms, tiny bubbles of atmosphere are trapped inside. This gives ice that frosty white appearance. When scientists take a section of an ice core and crush it in a vacuum, the tiny bubbles of ancient atmospheric gas are released. Scientists then examine the gases as a way to characterize ancient atmospheres.

Several deep ice cores have been completed in Antarctica, most notably, the Vostok ice core and the Dome F ice core. Large drilling rigs bored about

http://earthobservatory.nasa.gov/Features/Paleoclimatology_OxygenBalance/






a mile down and produced ice cores about a mile long.

Preparing ice core equipment in Antarctica.

In addition to ice cores, the Earth archives past environmental conditions in the sediments on the ocean floor and on lake bottoms. Scientists collect cores of bottom sediments which also display annual layering properties. Also, coral reefs and even stalactites in caverns are studied for climate information.

By examining the ice cores, bottom sediment cores and many other proxy archives collected from dozens of locations around the world, scientists have been able to reconstruct ancient global temperatures and ancient global atmospheres 800,000 years back in time.

The image below represents results obtained from the Vostok ice core, dating back 420,000 years. The top line indicates the amount of change in the average global temperature. The middle line indicates the amount of carbon dioxide in the atmosphere.

Vostok ice core data.

Notice that when the Earth is warmer, the amount of CO2 is higher; and when the Earth is cooler, the amount of CO2 is lower. It is this relationship that compels scientists and policy makers to consider the implications of the recent big increases in atmospheric CO2. Below, is an image that shows the correlation between recent global temperature and recent atmospheric CO2 levels.

Recent global CO2 and temperature trends. The baseline temperature reference is the average temperature from 1901-2000. Blue bars are below this average, and red bars are above.

In the Vostok ice core and others, the amount of atmospheric CO2 never exceeded 300 parts per million (ppm). But today it does. As of January 2018, atmospheric CO2 was over 407 ppm. This is about 35% higher than the maximum amount observed in ice cores dating back 800,000 years.

Because CO2 and global temperature appear to be historically linked, scientists generally agree that the recent global warming trend is being caused mainly by increases in atmospheric CO2 and other greenhouse gases.

There are other human-caused factors that can influence global temperature – both warming and cooling, but the overall analysis points to greenhouse gas emissions as the main cause for the recent warming. A study done by P.V. Forster and others (Forster, et al., 2007) assessed the relative warming and cooling influences by natural and human activities. They found that the overwhelming majority of recent warming is caused by human activities – mainly the release of greenhouse gases. A graphic from their study is presented below.


Human and natural influences on global temperature.

These findings lead to three questions:

1) How much warmer is the planet going to get?

2) How is this warming going to change climate patterns around the world?

3) What kinds of environmental and economic impacts will result from these climate changes?

General circulation models. Let’s take questions 1 and 2 first. Making reasonable predictions about the behavior of the planet’s future climate is a very, very hard task. To accomplish this task, scientists have had to start from scratch, accumulate knowledge and skills, and then build. Their efforts have led to the development of sophisticated climate models called, “general circulation models.” These models allow scientists to simulate the global climate system and to make predictions on how it will behave under different scenarios.

In order to create and use general circulation models, scientists have had to do a great deal of preparatory work which includes the following six steps.

1. Characterize the current global climate system. Scientists have accomplished this task by establishing a network of thousands of weather stations around the world. In addition to having ground-based instruments, many weather stations also release weather balloons on a daily basis. Weather balloons collect and report

atmospheric conditions at different altitudes, giving meteorologists a 3-dimensional perspective of the atmosphere.

2. Understand the physics of climate components. Given this characterization, scientists try to understand the physical forces involved. To do this, scientists examine the atmosphere’s physics involving radiation, heat, pressure, momentum, circulation, chemical composition, chemical reactions, moisture content, clouds and more.

3. Develop abstract models of climate operations (General Circulation Models). Once the physics of the atmosphere is generally understood, scientists try to encapsulate the total behavior of the atmosphere by creating an abstract model to represent it. Atmospheric models have many components. They can include drawings of the atmosphere to represent the spatial organization of its components. In addition, a flow diagram will graphically represent interactions between the different compartments of the atmosphere. Ultimately, the model is boiled down to a large mix of numerical equations representing the totality of physical and chemical interactions in the atmospheric system.

Abstract model of global climate system.

4. Write computer code to numerically represent the general circulation model operations. Given the enormous number of numerical equations in a general circulation


model, scientists are faced with a tyranny of numbers – too many calculations for one human, or even a large team of humans to perform in a reasonable amount of time. So scientists use computers to perform these calculations quickly. They write programs, mostly in FORTRAN, to automate and speed up the model’s calculations.

5. Design and build super computers to run general circulation model simulations. Scientists need fast computers to run their general circulation model programs. In response, computer scientists and electronics engineers continue to build faster and faster computers. As of late 2012, the latest Cray computer is the world’s fastest, being able to perform 16 quadrillion floating point operations per second (FLOPS). Ideal for today’s complex general circulation models. By comparison, these supercomputers are about 23 million times faster than the average desktop computer that runs at about 7 billion FLOPS. Using these super computers, you could run Call

of Duty® at over 100 million frames per

second. 6. Test the model's reliability by testing if

can predict past climates. Scientists test the accuracy of their general circulation models by seeing if they can predict past climates. For example, we have good records for atmospheric conditions, weather and climate for the years 1880 and later. Records provide details of how the global climate has changed from 1880 until now. For example, to test their models, scientists enter in a start date in 1880 and set the general atmospheric parameters to match those on record for that time. Then they let the model run. If the model can accurately simulate the global climate between 1880 and today, then the model is likely to be able to accurately predict global climate.

After decades of effort by scientists, dozens of general circulation models have been produced by research labs in many countries around the world. These models continue to be refined and improved. The results from these models all generally agree. A summary of their key findings is presented below:

Increasing greenhouse gas emissions are predicted to have the following effects on the global climate:

Global warming will increase Earth's average temperature. Average global temperatures are expected to increase by 2°F to 11.5°F by 2100, depending on the level of future greenhouse gas emissions. The high northern latitudes and continental interiors are projected to experience warming in excess of this average.

Global warming will influence the patterns and amounts of precipitation. Rainfall and snowfall are projected to increase planet-wide because of warming. Storm intensity is projected to increase especially in tropical and the high latitudes of the northern and southern hemispheres. Heavy precipitation downpours are likely to increase resulting in increased instances of flooding. Fueled by warmer ocean waters, hurricanes are projected to be more intense with stronger winds and more rain.

Global warming will reduce ice and snow cover, as well as permafrost. The decline of the Artic sea ice will continue. The ice will become thinner and may completely disappear during the summer months. Loss of Artic ice reduces global reflectivity of incoming sun (albedo). Increases planetary heat uptake and speeds up global warming. The coastal regions of the Greenland and Antarctica ice caps are projected to slide into the ocean. The permafrost in the Arctic will continue to melt, releasing millions of tons of now-frozen methane into the atmosphere. As methane is a strong greenhouse gas, its release will accelerate warming.

Global warming will raise sea level. Global warming contributes to sea level rise by: 1) thermal expansion of ocean water; 2) melting of mountain glaciers; and 3) melting portions of the land-based ice on Greenland and Antarctica, the melt-water of which flows to the sea. Moderate projections indicate global seal level will rise about two feet by the end of the century. This will cause coastal flooding in many low-lying coastal areas. In addition, coastal areas will be more vulnerable to flooding from storm surges.

Increases atmospheric CO2 will increase the acidity of the oceans. CO2 is very soluble in water solutions. Beverage makers put CO2 gas into soda to give it that fizz. Pop the cap, release the pressure, and the CO2 comes out of solution as thousands of tiny bubbles. But when CO2 dissolves in water, it


interacts chemically with the water to create an acid – carbonic acid. And this is what is happening to the oceans. As more CO2 goes into the atmosphere. More of it dissolves into the oceans. As more CO2 dissolves in the ocean, more carbonic acid is made, and the oceans become more acidic.

Scientists estimate that the oceans have already experienced significant increases in acidity. As CO2 emissions remain high, they project acidity will increase. Acidification is harmful to living systems in two ways: 1) it creates biochemical stress, as biochemical reactions inside cells are very sensitive to pH; and 2) it makes it difficult for many marine organisms to solidify hard body parts out of calcium carbonate. – like marine plankton, corals, mollusks (clams and snails), sea stars, sea urchins and some marine algae. Given that calcium carbonate-shelled plankton make up a significant part of the base of the marine food web, and given that they are vulnerable to acidification, scientists are worried about future catastrophic collapses in marine ecosystems due to increased acidification.

The magnitude and speed of these changes will depend on the rate of greenhouse gas increases and other unpredictable influences from the natural environment. A large part of future warming is dependent upon how humans change (or not) the quantity of greenhouse gas emissions. Scientists can’t predict future governmental policies, but their models can predict warming patterns under different possible emissions scenarios.

A study by G. A. Meehl and others examined the patterns of global warming under three different scenarios (Meehl, et al., 2007). The below graphic represents their findings.

Predicted global temperatures. The above image represents projected changes in global average temperatures under three emissions scenarios (rows) for three different time periods (columns).

Changes in temperatures are relative to 1961-1990 averages. Scenarios: B1 (top row) is a low emissions scenario, A1B (middle row) is a medium-high emissions scenario, and A2 (bottom row) is a high emissions scenario.

So I have addressed the first two of the three questions I asked above. But what about the third question? What kinds of environmental and economic impacts will result from these climate changes?

Global climate change will influence the distribution patterns and behavior patterns of many species. For example, because of shorter and milder winters, the Mountain Pine Beetle has significantly expanded its range. It has moved into higher elevations on mountains, and it has moved farther north, deep into the Taiga of Canada and Alaska. The beetle lays its eggs under the pine tree’s bark. When the eggs hatch, the beetle larvae feed on the food-rich underlying cells and otherwise disrupt the normal flow of water, minerals and food between the roots and the pine needles. The recent outbreak of Mountain Pine Beetles has destroyed millions of trees in North America.

Trees killed by pine beetles on Mount Fraser in Alberta, Canada.

In a similar example, the expansion of warmer climates to higher elevations and into subtropical latitudes may increase the distribution of two dangerous insect-borne diseases; malaria and dengue fever. Mosquitoes carrying these diseases generally operate in tropical regions and at low elevations. But as the warm zones expand out of the tropics and into the subtropics, there is concern that the mosquitoes will follow. In addition, historically, tropical lands at higher elevations have been free of malaria because they are cooler regions. The African Highlands of Kenya and Tanzania are examples. But as temperatures increase, there is concern that the malaria-carrying mosquitoes will follow.


Global climate change is already influencing other changes including migratory timing, egg-laying timing, spring flowering synchronization and much more. Ecologists are very interested in how natural populations will adjust (or not) to new and developing climate patterns worldwide.

Current human civilization is based largely on a foundation of thousands of years of predictable climate patterns. Farming regions are established next to flowing rivers or in regions that receive substantial rain. Coastal cities are established along bays. Dams are constructed on rivers and the water collected is transported to distant cities that are utterly dependent on imported water. Substantial investments in time, land, sweat and treasure But what if these time-true patterns begin to change unpredictably? What then?

Global climate change presents special challenges to human enterprise on all levels. For example, energy production. Today, most electricity is produced by power plants that burn coal or fuel oil – which release huge amounts of CO2. It is especially challenging to figure out how to reduce these CO2 emissions without severely disrupting the economy.

There is great interest in developing energy production systems based on solar, wind and tidal energy. There are several problems. First, solar plants produce no energy at night and little during cloudy days. In addition, it is not always windy at wind farms. So, these alternatives may be useful for supplementing fossil fuel power plants, and may reduce the need to build more, but they are unlikely to replace them.

After a 20-year hiatus, nuclear power is starting to be reconsidered as a practical alternative to fossil-fuel-burning power plants. Nuclear power plants produce no emissions because they don’t burn anything. The energy comes from the radioactive decay of Uranium fuel. But, as we have seen with the nuclear disasters at Chernobyl in 1985, and at the Fukushima plant in 2011, when things go terribly wrong at a nuclear plant, hundreds of square miles around the plant become dangerous and uninhabitable for decades. Still, given the urgency of reducing CO2 emissions, nuclear is holding its own in continuing discussions about the future of energy production.

Or what about cars? They burn gasoline which releases CO2. As millions more gasoline-powered

cars are added to the roads of China and India every year, in addition to the hundreds of millions of cars in the USA and elsewhere, how can we rethink personal transportation to reduce these emissions? These represent special challenges to vehicle manufacturers and city planners. Recently, there has been great progress in hybrid gasoline-electric technology. Many car manufacturers worldwide now offer at least one hybrid model. Although they still have a gasoline engine, hybrids get about twice the mileage of a standard automobile. In a report by the California New Car Dealers Association, the Toyota Prius was the top-selling car in California in 2012. However, this same car was not popular in the remaining 49 states. This points to another problem – public education and conditioning. The changes that futurists are proposing are likely to be strongly resisted by an uninformed and inflexible public.

Toyota Prius.

Water providers are especially concerned about global climate change, especially in the southwestern USA. Southern California and the states of Nevada and Arizona get very little rainfall. Yet they have big cities with millions of people. These regions are dependent on imported water from the Colorado River. The river gets its water from melting snow on the Colorado Rocky Mountains. There is great concern that, because of global climate change, the Rocky Mountains might receive less annual precipitation. If so, the regions downstream that depend on it will be in jeopardy. For the coastal regions of California, desalinization plants could transform seawater into drinking water. The problem is that desalinization takes enormous amounts of energy. Where is that energy going to come from? If, from a fossil-fuel power


plant, then this might not be acceptable to many as a response to global climate change.

Food producers have significant concerns. They have to choose which varieties of crops to plant. Some food-growing regions will experience significant long-term reductions in rainfall. Or they will experience significant long-term increases in rainfall. How do farmers plant for that? Think about the previous example on the Oklahoma Dustbowl catastrophe of the 1930s. An extended drought resulted in the collapse of the region’s economy. Although farmers are better informed now, climate changes still represent significant risks to their crops, their finances, and the banks that underwrite the farm’s operations.

First responders also could be affected. These are police, firefighters, and paramedics. The trained professionals who try to save life and property during an emergency. First responders are challenged by spreading wildfires and flooding. For the years of 2010-2012, large regions of Texas and other southern states experienced numerous large wildfires due to an extended drought. Fire fighters were over-extended at hundreds of fires. Global climate models project that some areas in the continental interior will experience less precipitation. Drier conditions combined with higher temperatures is a prescription for wildfire.

Firefighters battle a wildfire near Fort Collins. Colorado in 2012.

On the flipside, models project that some areas will receive more precipitation. In addition, the rain will come in more intense storms that deliver higher quantities of rain. This means more instances of flooding. Recent flooding in the northeastern USA, especially from Hurricane Sandy in 2012, challenged first responders to find and rescue stranded residents. If there are increases in

wildfires and flooding, agencies that provide emergency services will face significant challenges.

The biggest concern about global climate change is “unpredictability.” And financial interests around the world don’t like unpredictability. Modern civilization is dependent upon the smooth flow of capital (money). And capital is more willing to flow through the world’s markets when it knows where it’s going, and when it knows what to expect when

it gets there. Take the big stockholders of Apple®, Inc. Apple’s stock goes up or down based on the shareholders’ collective sense about the future. If there is uncertainty, shareholders sell and the price of the stock goes down. That’s why spokespersons for any publicly held corporation always strain to present an image of confidence, promise and hope about the future.

But what if climate change rattles markets with unpredictability? Coffee crops in Columbia are depressed because of drought; coffee becomes too

expensive; people visit Starbucks® less; managers layoff Starbucks employees; seeing less earnings, shareholders sell and the value of Starbucks stock declines. Imagine an accumulating history of little scenarios like this. Farmers unable to pay off their crop loans due to failed crops. Investors losing money underwriting companies dependent on predictable climate. In such cases of unpredictability and the fear of unreasonable risk, capital flees the marketplace and seeks shelter in low risk cash markets or government bonds. When this happens, less money flows through the global economy, and there is the possibility of recession or depression. So, although there are many technical challenges associated with global climate change, they all boil down to one huge challenge to the stability of our evolved and mysterious global economic system – upon which we are all dependent.

Uninhabitable regions due to increased heat stress

There is one last item of interest. And it the most worrisome of all. It has to do with the physiological property of heat stress. Heat stress occurs in all living things when exposed to high temperatures. This book has addressed the many ways living things can cope with temperature extremes; behaviors like shuttling in and out of the sun; burrowing deeper into the cool underground; or physiological mechanisms like evaporative cooling.


I want to address evaporative cooling in particular. As we have seen in ch.3, sweat or panting delivers warm body fluids to the body’s surface. From there, the fluids evaporate into the air, taking heat away from the body, thereby dropping the body’s temperature. Evaporative cooling allows animals to stay active even when the surrounding air temperature exceeds the body’s optimum operating temperature – which is 98.6° F for humans. But what if evaporative cooling doesn’t work anymore. This can happen when the relative humidity reaches 100%. When the relative humidity is 100%, the atmosphere is saturated with water vapor. Under such a condition, the surface moisture normally used by animals for evaporative cooling – that moisture will not evaporate. Then, there is no more evaporative cooling.

This situation becomes especially concerning if the air temperature is also high. Under conditions of high temperature (95° F or higher) and 100% relative humidity, humans and other animals very likely will suffer fatal heat stress (hyperthermia) and die. So, there is a limit on how much temperature gain humans and other animals actually will be able to tolerate if the planet continues to get warmer and warmer. Is this something we should worry about? Short answer: Absolutely!

Two scientists, Steven C. Sherwood and Matthew Huber, investigated this problem and predicted that within the next 300 years, large portions of the planet could be uninhabitable due to heat stress dangers (Sherwood & Huber, 2010). The scientists estimate that the trigger point for this issue is an increase in the global mean temperature of 7° C (12° F). Once the planet warms to this level, large portions of the planet will become intolerable for humans and other animals. With an increase of 11-12° C (20-22 °F) most of the territory now occupied by humans will become uninhabitable (without constant assistance from artificial cooling). Below, is one of the maps from their study.

Regions colored light yellow and magenta would be uninhabitable without artificial cooling. From (Sherwood & Huber, 2010).

The above map represents the distribution of heat stress zones with a global mean temperature increase of 11-12° C (20-22 °F) – which is possible within 300 years – given current trends. Uninhabitable areas include most of the eastern USA, nearly all of Amazonia, western Africa, Spain, much of the Middle East, most of India, eastern China and nearly all of Australia.

What can you do to help slow global climate change?

The main point is for you to reduce your energy consumption. Here are some ways for doing this:

• Replace light bulbs in your home with Energy Star fluorescent or led lights. These can be expensive so at first, select the bulbs that are on most.

• Turn off lights when rooms are not in use.

• Configure your computers to “sleep” when you are away.

• When you can, buy recycled paper for your computer printer.

• Have your central AC system serviced: fix leaks, recharge coolant.

• In summer, use natural cooling more intelligently. At night, turn the AC off and open windows. Seal up the house again at mid-morning it starts getting hot outside.

• Adjust your thermostats a bit lower in winter and a bit higher in summer.

• Add more insulation to your home.

• Fix or replace windows that let out cool air in summer or let out warm air in winter.

• Use less water around your home. Lose the lawn. Landscape with drought tolerant plants. Remember, water is free. What you pay for is the costs of delivering it to you, much of which is the cost of energy to pump it.

• Turn down your water heater.


• Drive a more fuel-efficient car. Seriously consider a hybrid for your next car.

• Don’t race from signal-to-signal. Sure, it’s sexy but it’s also a huge waste of fuel and adds more greenhouse gases than necessary to get around. Develop a softer right foot and save money.

• Use public transportation or carpool when possible.

• If you are relocating, try to move close to public transportation hubs or metro stations.

• Bring your own cloth grocery bags to the grocery store.

• Use a refillable water bottle instead of buying water every day. And don’t lose it.

• Recycle, recycle, recycle.

• Become a smarter consumer. Don’t be so easily influenced by sexy ad campaigns. Think for yourself about the expense, necessity and environmental impact of things you buy.

Spoiling the air - air pollution

Smog

It has been labeled the “Airpocalypse.” In mid-January 2013, the city of Beijing, China and nearby regions experienced the worst persistent smog episode in recent times. On January 14, 2013, the Beijing Municipal Environmental Monitoring Center reported the air had exceeded 700 micrograms of particulate matter (PM 2.5) per cubic meter. According to the World Health Organization, air this polluted is “hazardous” to breathe.

Smog in Beijing, China. 2013.

By comparison, in 2011, in Los Angeles air basin, the maximum amount of particulates (PM 2.5) experienced in a 24-hour period was 65 micrograms per cubic meter. The 24-hour maximum allowable concentration of particulates (PM 2.5) in the United States is 35 micrograms per cubic meter. The World Health Organization’s PM

2.5 standard for healthy air is 25 micrograms or less per cubic meter.

Hazardous air pollution episodes have occurred elsewhere around the world, generally as a result of concentrated industrialization and growing populations in metropolitan areas. For example, in December 1930, 60 deaths were attributed to a 3-day smog episode in the Meuse Valley, Belgium. During a 1948 smog episode in Donora Pennsylvania, there were 20 premature deaths and thousands were stricken because of dirty air. London’s Great Smog of December 1952 was responsible for thousands of premature deaths and more than 100,000 severe cases of respiratory illnesses.

In the years leading up to 2000, the Los Angeles air basin (including the counties of Los Angeles, Orange, Riverside and San Bernardino) experienced frequent smog episodes. There were 121 Stage 1 smog episodes in 1977. The worst smog episodes were classified as Stage 2 smog episodes. Stage Two episodes were so bad that people were urged to stay indoors, and all playground and athletic activities were cancelled at affected schools. For many, eyes stung and breathing became painful. These smog episodes were accompanied by many deaths among people who were vulnerable to such dirty air. In 1978, there were 23 Stage 2 smog episodes in the L.A. air basin. The last Stage 2 smog episode occurred in 1988. The last Stage 1 episode occurred in 2003.

The term, “smog,” comes from the combination of two words, “smoke” and “fog.” Smog episodes like the ones mentioned above are the result of special atmospheric conditions (thermal inversion) and large quantities of emissions from power plants, factories and cars. The chemical content of smog can vary from region to region but mostly is the result of burning fossil fuels. In many places, large power plants burn coal or fuel oil to make steam. The steam turns a turbine that is connected to an electricity generator. Cars, trucks, trains, and planes burn gasoline, diesel and jet fuel. In a large metropolitan area like Beijing or Los Angeles, these vehicles can burn millions of gallons of fuel a day. In 2008, human activities released about 450 tons of emissions into the Los Angeles Air Basin every day. The emissions from all this burning produce a mixture of chemicals and particles that make up smog.

http://www.aqmd.gov/smog/historical/AQ11card.pdf




http://www.aqmd.gov/smog/o3trend.html


http://www.aqmd.gov/news1/Archives/ozone_trends.htm





http://www.arb.ca.gov/app/emsinv/emseic1_query.php?F_DIV=0&F_YR=2008&F_SEASON=A&SP=2009&F_COAB=Y&F_AREA=CO&F_CO=19&F_DD=Y




The smokestacks from fossil-fuel-burning power plants release mostly sulfur oxides (SOx), nitrogen oxides (NOx), and particulates (microscopic particles) that can be seen as smoke. Vehicles also release these pollutants. In addition, vehicles release hydrocarbons (vapors of unburned fuel). Under normal atmospheric conditions, these emissions disperse into the generally unstable atmosphere and are carried away by the winds. By this action, the city’s air pollutants do not accumulate, and the air quality may not be noticeably bad.

Sometimes the atmosphere over polluting cities becomes very stable. The wind stops and the air becomes very settled. At night, the air cools. Under this regime, the cold air sinks toward the ground due to its higher density. By morning, the still air is stratified (layered) with a mile-thick lower layer of cool air that is covered by a layer of warm air up high. This condition is called a “thermal inversion.” Normally, air gets cooler as you go higher. But in a thermal inversion, this temperature trend is reversed. The key effect is that in a thermal inversion, there is a distinct boundary between the lower cool air mass and the higher warm air mass. That boundary acts as a barrier that prevents mixing of the air below with the air above. The significance of this condition is that the emissions from the city are not able to disperse into higher altitudes. Instead, they accumulate near the surface. If the city is bordered by mountains, as are the cities of Beijing, Los Angeles and Mexico City, the mountains prevent horizontal dispersal of emissions. The combination of high emissions, thermal inversion and blocking mountains results in the rapid buildup of emissions near the ground, triggering a smog episode.

Trapped by a thermal inversion, thick smog accumulates in the Los Angeles basin in 1972.

Certain emissions are most problematic in wintertime smog episodes, like the Beijing Airpocalypse of 2013, the Meuse Valley smog of 1930 and London’s Great Smog of 1952. They are SO2 and fine particulates. These are the primary pollutants. And the smog that results is called “Classical Smog.” But in summer, a new toxic chemical is created following reactions among some of the primary pollutants. That new chemical is ozone. Ozone is created following the reaction of hydrocarbon vapors and nitrogen oxides in the presence of ultraviolet radiation. The newly-formed ozone is especially toxic. Smog that has large amounts of ozone is called “Photochemical smog.” This is the type of smog associated with Los Angeles.

The pollutants in smog are harmful to human health. They are especially dangerous for certain high risk groups including infants, the elderly, and the infirm (people struggling with an illness or other stressful medical condition). Air pollutants can seriously aggravate chronic respiratory ailments including asthma, emphysema and chronic bronchitis. Air pollutants can cause significant damage to cells lining the lungs causing inflammation and reducing lung capacity. And they can reduce the respiratory system’s ability to fight infection.

Air pollution also harms ecosystems. Particulates will settle on plant leaves, blocking access to the sun and reducing photosynthetic productivity. Air pollutants can harm respiratory systems in animals and make them more vulnerable to respiratory infection. These pollutants also can reduce overall vigor of plants and can reduce yields in crops.

Following many years of destructive smog episodes, many industrial societies have taken action to clean up their air. The Clean Air Act of 1970 gave the federal government of the United States authority to set and enforce limits on air pollution. In California, this law is now implemented (with some localized additions) by the California Air Resources Board. Regionally, the South Coast Air Quality Management District enforces the law in the greater Los Angeles air basin.

The Clean Air Act and related air pollution control laws set standards for acceptable emissions from stationary sources like power plants and factories, and mobile sources like cars and trucks. These standards are set in order to prevent smog


episodes and to create an environment with healthy air.

It has been a costly endeavor. Stationary emitters have had to invest in new air pollution control technologies that reduce emissions from their operations. Gas stations have had to invest in costly vapor recovery systems so that gas fumes don’t escape from your gas tank while filling up. Vehicle manufacturers have had to implement costly smog control equipment like smog pumps and catalytic converters. Gasoline refiners have had to develop new formulas for less polluting fuels. Paint manufacturers have had to develop new formulas for paints that release fewer emissions into the air while drying. Automobile owners must pay to get their cars smog-checked every two years and make expensive repairs if necessary. Some operations have not been able to adapt to the new restrictions and have had to leave the area. Furniture manufacturers, for example.

Despite the great expense, the Southern California economy has not collapsed because of air pollution control laws. And the air is remarkably cleaner than it was 40 years ago even though there are millions more people living in southern California today, driving millions more cars. Smog episodes are a thing of the past for most US cities. Were it not for the Clean Air Act and the ingenious technologies that followed, the air in many cities across the USA today would resemble that of Beijing’s Airpocalypse of 2013.

Acid Rain

While smog episodes were peaking during the 1960s in the USA and Europe, another odd phenomenon was puzzling environmentalists. They had observed that many lakes in the northeastern USA and northern Europe had become acidic. In some cases, the lakes were so acidic that fish and many aquatic plants could no longer live in them. The forests around the lakes had become noticeably distressed, especially on mountaintops. Millions of trees had died for no apparent reason. In 1967, Swedish professor, Svante Oden, published an article in a Swedish newspaper that linked the death of lakes and trees to acidic rain.

Acid rain effects on a forest in central Germany. 2007.

Following Oden’s article, the Swedish government and eco-minded people in Europe mobilized a global campaign to bring awareness to the problem of acid rain. As Oden proposed, fossil fuel emissions from cars and power plants in the United Kingdom and Germany were the cause of acid rain. The nitrogen oxide and sulfur oxide emissions react in the atmosphere to make nitric acid and sulfuric acid. These acids remain in the clouds for a time and then fall with the rain, acidifying the objects they contact.

pH is a property of water solutions that indicates the relative abundance of free hydrogen ions (H+) and free hydroxide ions (OH-). The pH scale ranges between 0 and 14. A pH value of 7 is neutral. When H+ ions outnumber OH- ions, the solution is acidic and the pH is less than 7. When OH- ions outnumber H+ ions, the solution is basic and the pH is greater than 7. The chemistry in living cells operates in a pH of about 7.3, which is slightly basic. Cells are very sensitive to changes in pH. Any deviation from the cell’s normal pH represents a stress on the system. So, plants and animals exposed to acidic ambient conditions will experience stress. The more acidic the environment becomes, the greater the stress.

In the USA, emissions from Midwestern cities make acids in the clouds as the air mass drifts eastward. Upon encountering mountains in the northeastern states, the acids fall with the rain with destructive results.

In addition to killing trees and lakes, the acids were dissolving statues and building structures composed of marble or limestone. Damaged works


of art include many carved objects on medieval European cathedrals, the Acropolis in Athens, Greece, and the Taj Mahal in India. Many other ancient works in Europe and Asia have been damaged.

Limestone sculpture damaged by acid rain. Europe.

ph Scale.

In response to public outcries to do something about acid rain, governments of polluting countries implemented new regulations to reduce acid-rain-causing emissions – namely nitrogen oxides and sulfur oxides. In the USA, new laws came into effect in 1980 with the Acid Deposition Act. Later, the Clean Air Act was refined to restrict acid-producing emissions. Fossil-fuel-burning power plants installed scrubbers to clean smokestack emissions. Alternatively, coal power plants could choose to burn low-sulfur coal, or to wash the coal of its sulfur before burning. The result has been about a 50% reduction in acid-producing emissions. Although this is an improvement, the problem of acid rain remains.

http://www.epa.gov/airmarkets/progress/ARPCAIR10_01.html


Stratospheric ozone depletion

In a previous section, I presented the harmful properties of ozone in smog. Let’s call that ozone, “tropospheric ozone.” The troposphere is the layer of the atmosphere closest to the Earth’s surface. Too much ozone in the troposphere is bad because it comes into contact with living things which find it to be toxic.

The ozone this section discusses is high up above the troposphere. It is in the stratosphere. Let’s call this ozone, “stratospheric ozone.” Stratospheric ozone is good because it helps block harmful ultraviolet radiation.

As we saw in chapter 3, ozone occurs in the stratosphere because of the optimum combination of the two most important components that lead to its formation: 1) molecular oxygen; and 2) ultra-violet radiation. It exists in a region of increased abundance starting at about 12 miles high. Its actual altitude and thickness varies, though. The ozone “layer” is not something you would notice as you passed through it on your next space flight. Still, even at very low concentrations, stratospheric ozone acts to shield the earth's living systems from harmful ultra-violet radiation coming from the sun.

In 1976, British scientists measuring stratospheric ozone levels over Antarctica discovered a 10% drop during the Antarctic spring. The springtime depletions worsened year-after-year. By 1983, after seven years of record-breaking declines, scientists became alarmed that the global stratospheric ozone layer was in jeopardy.

Stratospheric ozone depletion over Antarctica, September 2017.

In 1985, scientists were able to determine conclusively that the loss of stratospheric ozone was due to chemical reactions between ozone and large amounts of chlorine introduced into the atmosphere by human activities. But which

activities?

It turned out that the chlorine in the stratosphere mainly was coming from the use of a purely synthetic chemical compound called “chloroflurocarbons,” (CFCs). CFCs were widely used in industrial nations as refrigerants in refrigerators, and air conditioning systems

in cars and homes. They also were used as solvents in the growing electronics industry, as blowing agents for making Styrofoam, and as propellants in aerosol cans. Since CFCs are non-toxic and not flammable, there was no interest in regulating their emissions. So, CFCs were freely vented to the atmosphere.

It turns out that the high stability of CFCs allows these molecules to persist in the atmosphere for many years. CFCs vented from an air conditioning repair garage in New York will find their way to Antarctica or anywhere else on the globe within a few months.

During the Antarctic winter, the atmosphere over Antarctica is isolated, dark and extremely cold. Because of the dark and cold, atmospheric chemistry is suppressed. But with the onset of spring and the return of the sun and warmth, there is a surge in chemical activity in the Antarctic atmosphere. This is when the chlorine, carried into the Antarctic stratosphere by CFCs, begins to react with stratospheric ozone.

Stratospheric ozone depletion is energized by ultraviolet radiation. First, Ultraviolet radiation knocks a chlorine atom off of a CFC molecule yielding a free chlorine atom. Simultaneously and independently, ultraviolet knocks an oxygen atom off of an ozone (O3) molecule yielding an oxygen free radical. Ordinarily, the oxygen free radical will recombine with O2 to re-make ozone (O3). But in the presence of the free chlorine atom, the oxygen

Freon. Widely used CFC.


free radical more readily combines with the chlorine atom to make chlorine monoxide. The ozone molecule is permanently destroyed. Each chlorine atom can be involved in up to 100,000 ozone-destroying reactions.

Since their discovery in the mid-1970s, the greatest depletions of stratospheric ozone have occurred at the earth's polar regions. Although these depletions are frequently referred to as "Ozone Holes", they actually are not holes in the atmosphere. Instead, the concentration of ozone decreases in these areas -- the combination of gases remains the same, except that there is less ozone.

The basic consequence of ozone depletion is that the earth's living systems will suffer from increased exposure to ultra-violet radiation (a form of ionizing radiation). This could result in the following:

Reduction of Photosynthesis

Photosynthesis will be reduced because of damage to leaves, and harm to phytoplankton. This also could result in a loss of molecular oxygen production. Since molecular oxygen is needed to make ozone in the first place, less oxygen means less ozone. This is known as a positive feedback loop -- or a snowball effect.

Increased Tropospheric Ozone

Ironically, loss of ozone high up in the stratosphere will increase the production of ozone in the lower atmosphere of our biggest cities. This is because more ultra-violet radiation will reach the lower atmosphere and energize photochemical reactions with air pollutants to make ozone smog.

Increased Acid Rain

The acids in acid rain form in the atmosphere when certain pollutants react with each other to make acids in the sky. Ultra-violet radiation energizes these photochemical reactions. More ultra-violet radiation, more acid rain.

Humans will experience an increase in the following ailments:

Increased Skin Cancer

Cancer is the rapid growth and division of cells that have no function. They just take up space and consume limited nutrients in the body. The cancer cells are not toxic, but they end up crowding out useful cells in organs, to the point that vital organs in the body lose their ability to function. Cancers are caused after there has been some change to the DNA of a cell. Not all DNA changes cause cancers, but some do. Ultra-violet radiation can break DNA molecules apart. If the right kind of damage is done to the DNA of a skin cell, a skin cancer can start. A real danger is that the cancer won't stay confined to the skin, but that some cells will be transported to other organs, where they will start new cancers.

Skin cancer.

Increased Cataracts

A cataract is a clouded lens of an eye. Ultra-violet radiation is known to cause long-term damage to the eye's lens, and can increase the onset of cataracts.

Increased Damage to the Immune System

The human body's white blood cells are central to fighting off invasions by microorganisms like bacteria and viruses. However, white blood cells are vulnerable to ultra-violet radiation. When white blood cells are in the skin, some ultra-violet radiation penetrates the skin and kills them. A reduction in healthy white blood cells will reduce the body's ability to fight disease.

In 1978, the USA, Canada and Norway banned the use of CFCs as propellants in aerosol cans out of concern that the CFCs would damage stratospheric ozone. However, other uses for CFCs were still


widely allowed. In 1987, the Montreal Protocol was initiated. The Montreal Protocol is an international treaty intended to protect global stratospheric ozone. The treaty attempts to achieve this goal by phasing out the production and emission of ozone-depleting chemicals like CFCs. To date, 197 nations have signed and ratified the treaty.

Although there has been significant progress in reducing ozone-destroying chemicals, seasonal stratospheric ozone depletions continue to appear over Antarctica and the high northern latitudes including North America and Europe. The updated and revised science indicates that it may be many decades before the depletions subside. Still, the political success of Montreal Protocol gives hope that international cooperation can be achieved in tackling a much larger global environmental problem – global climate change.

Spoiling the water - water pollution

Water presents humans with a problematic mix of good and bad. Humans and all life naturally congregate near surface water resources like ponds, or streams or rivers. Access to water is good. Humans use it for drinking, cooking, bathing, cleaning, irrigation, and many other activities. Because of the usefulness of water, human congregations near such water resources have

tended to grow. These large human populations present the problem, because not only are people using the river as a source of drinking water, they also use the river as a receiver of wastes. The simplicity of the system goes like this. A village along the river (Village No. 1) pulls water out and uses it. That same village then dumps various wastes into the

river, and the river water takes it away. Life is easy and beautiful – except for the villagers downstream (in Village No. 2). The water flowing by their village

is not so pure. It has been polluted with human wastes of all sorts from the village upstream. This is bad. Faced with no alternative, Village No. 2 uses the water anyway and adds its wastes to the river. This pattern repeats as the river makes its way to the sea. As you can imagine, the river becomes more and more polluted as it passes by each village.

The implementation of simple sewage systems occurred in various forms in civilizations around the world. Archaeologists have uncovered evidence of public and private latrines (pit toilets) connected by masonry ditches or pipes, leading to cesspools and eventually discharged into local rivers. Some dating thousands of years ago. In many cases where residents had no access to latrines, body wastes were collected in chamber pots and tossed out onto the street. This was especially the case in medieval European cities. Instead of pipes, some early sewer systems conveyed wastes in a system of open trenches along streets. Remarkably, the present day city of Port-Au-Prince, Haiti has such a system. This is a city of three million people.

Eventually, cities installed covered sewer systems that transported body wastes through a system of underground pipes and dumped them into the nearby river.

As you can imagine, there were many environmental problems associated with these practices. Cities with open sewer systems were filthy and foul-smelling locales that experienced frequent epidemics of cholera and typhoid. These and other deadly diseases were spread by ingesting water or food contaminated with human feces.

Eutrophication

In the receiving river or lake, the untreated sewage created a different set of environmental problems. I am going to focus on one form of environmental degradation called, eutrophication.

Eutrophication can be caused by the dumping of untreated sewage. Storm water runoff from heavily fertilized watersheds, like commercial nurseries, farms, golf courses and city parks also can result in eutrophication.

Eutrophication literally translates to mean, truly well fed. It is a condition of aquatic environments in which the oxygen in the water has been completely depleted. The oxygen is depleted because there is an overabundance of microbiological aquatic life that is engaged in consuming it from the water.

In medieval times, dumping chamber pots onto the street was normal practice.


There is an overabundance of aquatic life because there is an overabundance of food in the water.

Eutrophic waters in a park’s pond. This situation caused by guests feeding ducks, and runoff of fertilizer from adjacent turf grass.

When untreated sewage is dumped into an aquatic environment like a lake or a river or an ocean, the sewage contains a great deal of organic material, mainly food wastes and toilet wastes. This organic material has high nutritional content that is exploited by microorganisms living in the receiving waters. As a result, plankton, bacteria and other small aquatic organisms feed on the sewage and their populations grow. The fixed carbon molecules in the sewage are taken in as food and are used to energize living operations through the process of cellular respiration Remember that aerobic cellular respiration consumes molecular oxygen…

Fixed carbon + O2 → CO2 + H2O + biological energy (aerobic cellular respiration)

The term, aerobic, means “pertaining to air.” As the population grows because of the overabundance of food in the sewage, more and more of the dissolved oxygen (O2) is removed from the water to support cellular respiration. But there is a limit. As dissolved oxygen continues to decline, there comes a point when there isn’t enough to support the ongoing demands for aerobic cellular respiration. When that point is reached, the blossoming aquatic community of microorganisms dies for lack of enough oxygen in the water. This massive death, coupled with low oxygen levels in the water results in a new population explosion of a different kind – an explosion of populations of anaerobic bacteria.

Bacteria

The term, anaerobic means “without air.” In biology, the term usually refers to a condition in

which molecular oxygen is absent (without oxygen).

Almost every natural ecological environment you have ever seen is filled with “aerobic” organisms. These are organisms that use molecular oxygen in the cellular respiration. As the Earth’s atmosphere is made up of 21% O2, living things are obliged to deal with oxygen as a matter of routine. But some kinds of living things cannot cope with molecular oxygen. These are the anaerobic organisms. To them, molecular oxygen is a poison; it disintegrates their molecules which halts all living operations. It kills them. Anaerobic organisms mainly are special kinds of bacteria that can only live in oxygen-free environments, such as the deep mud on the ocean bottom, or in the mud in the bottom of a pond or lake.

Since anaerobic organisms cannot be exposed to free, molecular oxygen, certain aspects of their biochemistry are different from those of aerobic organisms. For example, in aerobic cellular respiration, molecular oxygen is used to collect waste hydrogen atoms and waste electrons and in the process all are converted to H2O (water). But anaerobic bacteria use an alternate process and an alternate waste hydrogen collector. In straight fermentation, waste hydrogen atoms are loaded onto carbon atoms to make molecules of methane (CH4).

Fixed carbon → CH4 + CO2 (fermentation)

In an alternate example, anaerobic organisms might use nitrate or sulfate salts (instead of O2) to collect hydrogen wastes.

When anaerobic organisms use nitrate salts (NO3-) in an alternative form of cellular respiration called nitrate respiration or denitrification, molecular nitrogen (N2) is returned to the atmosphere and CO2 and water are produced as well. Overall, this is a good thing for all ecosystems as none of the products are toxic, and molecular nitrogen is once again available to help build new life.

Fixed carbon + HNO3 → N2 + H2O (denitrification)

When anaerobic organisms use sulfate salts (SO4 2-) in an alternative form of cellular respiration called fermentation, the waste hydrogen atoms are attached to sulfur to make hydrogen sulfide (H2S), and CO2 and water are produced. Generally, hydrogen sulfide is toxic to aerobic organisms. This


is one of the main problems that accompany the shift from an aerobic environment to an anaerobic environment. The production of hydrogen sulfide can significantly stress or directly kill any lingering aerobic organisms in the area, like fish, mud-dwelling invertebrates, plankton, and aquatic plants.

Fixed carbon + H2SO4 → H2S + CO2 + H2O (fermentation and sulfate reduction)

In summary, eutrophication is an undesirable environmental condition because it results in:

• the depletion of dissolved oxygen

• the production of toxic biochemical products

• the death of much of the normal aerobic flora and fauna

In modern industrial societies, there are many different kinds of wastes that, if not controlled, would find their way to the river. In addition to bathroom and kitchen wastes from homes and businesses, there are industrial wastes. These are wastes from manufacturing operations such as small fabrication shops or large factories. Industrial wastes include environmentally unfriendly materials such as acids, heavy metal chemicals, oils, and toxic organic chemicals. Historically, large factories were built alongside rivers for the intended purpose of dumping untreated wastes directly into the river.

One dramatic example of uncontrolled industrial dumping is the Cuyahoga River in northeast Ohio. The river has caught fire several times because of the abundance of flammable wastes dumped into the river by adjacent industries. The fires would sometimes spread to riverfront developments like boat docks and buildings. The last and most spectacular fire occurred in 1969. That river fire was widely publicized and triggered a public outcry for more pollution controls. This led to the development of progressive new laws intended to protect water quality in the USA.

Cuyahoga River catches fire near Cleveland, Ohio in 1952.

The Clean Water Act was passed in 1972, and the Environmental Protection Agency was established to enforce it. The law focuses on preventing polluting discharges into waterways such as lakes, rivers and oceans. In response to this law, factories were required to treat their wastes onsite to an acceptable standard, prior to discharge. If that wasn’t possible, factories had to send their wastes, either in drums or by tanker truck, to a landfill for disposal. This led to a new problem – illegal dumping of hazardous chemical wastes onto the land – which resulted in a new environmental crisis. This toxic chemical waste crisis will be discussed in the next section, “Spoiling the Land.”

Cities were obliged to improve sewage treatment before discharging it into a waterway. Congress supplied funds to build new sewage treatment facilities all across the country. Dischargers are obligated by law to frequently test their wastewater after treatment and report their findings to the EPA. As a result of all the actions required by the law, the water quality in the nation’s water ways significantly improved.

Activated sludge sewage treatment. LACSD.


Trickling filter sewage treatment. OCSD.

The Clean Water Act dealt with the disposal end of the water use cycle, discharges into water ways. What about the consumption end of the water use cycle? When you go to your sink and fill a glass of water or wash a head of lettuce while preparing a salad, you expect the water to be clean and pollution free. The Safe Drinking Water Act was passed in 1974 to ensure the nation’s drinking water supply is healthy to drink. To implement the act, drinking water suppliers (like the Metropolitan Water District in southern California) built or improved water treatment facilities. Generally, municipal water suppliers will draw water from nearby rivers or from underground aquifers. Thankfully, because of the Clean Water Act, the river water is not loaded with dangerous pollutants. Still, that water needs additional treatment before you can drink it safely. Treatment methods will vary, depending on the source, but usually include removal of dissolved solids, micro-filtering and disinfection with chlorine.

The combination of improved sewer design, improved wastewater treatment, and improved drinking water treatment has resulted in cleaner, more pleasant smelling and disease-free cities.

[Author’s notes]

Pesticides – acute effects, sex hormone mimics, long-term effects (DDT), evolutionary effects (pest resistance)

Biological and ecological impacts

Groundwater pollution – from landfills, from industrial operations, USTs from gas stations,

Biological and ecological impacts

[end author’s notes]

Spoiling the land

It is one thing for humans to clear the land and put it to good use. It is quite another for them to spoil the land and render it useless if not downright dangerous. This section describes the many ways ingenious and enterprising humans have laid waste to the Earth’s surface.

Topsoil erosion

The erosion of topsoil continues to be a vexing environmental problem. Topsoil is the rich top layer of soil from which plants absorb valuable mineral nutrients. The depth and material make up of topsoil varies from place to place. For example, the Central Valley of California and much of the converted prairies in the country’s heartland have thick (over one foot), mineral-rich topsoils. These excellent topsoils support high agricultural productivity. By contrast, the tropical rain forest has very thin topsoils, often less than an inch thick. Humans don’t intentionally destroy topsoil, but topsoil nonetheless gets destroyed because of human activities.

For example, in the recent 200 years in Madagascar, much of the western woodlands were harvested for timber. The growing human population scavenged the remains for firewood. But there was no successful effort to replace the trees or to reestablish the former functioning ecosystem. As a result, the land previously occupied by scrubby woodland became a gigantic barren, populated by a sparse assemblage of short, weedy plants. As roots penetrate into the topsoil, they tend to form a network of fibers that hold the topsoil together and keep it from eroding during hard rain. Once the trees and most other plants were gone, there was little or nothing to hold onto the topsoil. As a result, rains quickly washed the topsoil away. So much soil is being washed into river systems that the rivers themselves are filling up with sediment. For example, the bay at the mouth of the Betsiboka River used to have a functioning harbor. But silt from eroded topsoil was carried into the bay, filled it in and eliminated the harbor. Today, much of western Madagascar is a wasteland of impoverished subsoils that reduce opportunity for plant recolonization.


Silt from eroded surroundings accumulates at the mouth of the Betsiboka River, Madagascar (June 2011).

Dust Bowl. Following the US Civil War, the normally dry panhandle area of western Oklahoma and northern Texas was settled by homesteaders who tried to make a go of it farming and raising cattle. Unusually wet years in the early 1900s convinced many in the area to invest heavily in intensive farming practices, which they did. Tractors were used extensively, and the soil was tilled relentlessly. Then, in the 1930s, the area was hit with a decade-long drought. Despite the reduced rainfall, farmers failed to adjust their soil management practices. Poor soil management was a problem not only because the soil became depleted of nutrients, but also because the frequent stirring of the soil by plows dried it out and made the topsoil vulnerable to the wind. For about 10 years, winds carried away the dry powdery topsoil by the thousands of tons, eroding topsoil from over 100 million acres of farmland. This environmental calamity (named, “the Dust Bowl”) caused an economic collapse in the region that coincided with the nation’s Great Depression.

Dust storm approaches Stratford, Texas in 1935.

These two examples of topsoil erosion are the result of unrestrained exploitation of the land. But there are ways to reduce topsoil erosion. One technique is called terracing, or contour farming. This technique could have saved most of the topsoil in Madagascar. The idea is to install rows of barriers along the contour lines of a slope. Barriers can be made of stones, or sandbags or even piled up crop wastes. Satellite images of Madagascar show little attempt at terracing. By contrast, satellite images of Kenya show widespread terracing. Now, terracing wouldn’t have helped the Dust Bowl farmers because it was the wind that was removing topsoil. Lessons have been learned. Today in windy areas, instead of leaving farmland bare between plantings, farmers plant cover crops like beans or grass to keep the topsoil in their fields “rooted.” Planting trees along property lines can act as wind breaks. Reducing deep soil tilling makes the topsoil less vulnerable to wind. Leaving soil-covering crop wastes can act as a protective covering, keeping the wind away from the topsoil.

Toxic chemical waste

Our modern world is filled with many useful products invented by clever marketers and engineers. They are composed of plastics and finished metal (your phone), or composed of a mix of synthesized chemicals (household cleaners). All this new stuff that we can’t seem to live without is made in factories – actually a network of factories. One factory synthesizes materials for another factory that fabricates parts, which are sent to another factory for assembly and packaging. Modern manufacturing involves very sophisticated operations that rely on a large stock of natural chemicals and a growing body of synthetic chemicals. Many of these chemicals are hazardous to living things. This is where the problem begins. Because each step in the manufacturing process produces waste. Although present day businesses in the USA are fairly good at managing hazardous wastes, the past is filled with examples when they weren’t.


Drums of hazardous chemical wastes leak into a swampy site in Texas (1973).

Here is an example. In the 1890s, Love Canal was named after William T. Love whose unfinished canal became nothing more than a mile-long, water-filled ditch in the town of Niagara Falls, New York. The “canal” soon became a dumping ground for the city’s waste. Local businesses also started using the canal as a dump, including the large chemical manufacturing plant operated by the Hooker Chemical Company. Under legal agreement with the local agencies, Hooker drained the canal and began to deposit 55-gallon drums of hazardous chemical wastes there. The operation lasted for 13 years between 1940 and 1953, after which the dump was filled in with earth and completely buried. In all, over 21,000 tons of toxic chemical wastes were buried in Love Canal. Although buried and out of site, the enormous mass of wastes below eventually intruded on the lives of people above.

Homes were built adjacent to the canal site, and a public school was built directly on the Love Canal site. Over the years, and because of remarkably uninformed choices made by local officials, local residents were exposed to a large array of dangerous chemicals seeping out of the dump and into their basements. Lois Gibbs lived in one of those houses. Her son began developing a series of serious health problems, the cause of which was a vexing mystery. In her investigations, she discovered the reason – leaking chemicals from the Love Canal dump near her home. She learned that many of her neighbors also suffered from disproportionately high numbers of health disorders that could be attributed to over-exposure to toxic chemicals including miscarriages, birth defects, nervous disorders and cancer. The milk in nursing mothers was even contaminated with the dump’s chemicals. In 1977, outraged, defrauded,

and victimized, Gibbs organized local residents and the press to bring national attention to the plight of Love Canal homeowners. They were being harmed by the toxic chemicals below their homes and they needed help. In 1978 a federal emergency was declared for the Love Canal area and federal funds were allocated to resolve this environmental catastrophe.

Love Canal protests circa 1977-78 (left). Lois Gibbs 2010 (right.

Coincidentally, in 1976, Congress had enacted the Resource Conservation and Recovery Act (RCRA), which was a landmark law governing the management and disposal of hazardous chemical wastes. The Love Canal incident added special urgency to the problem of hazardous waste disposal. In 1980, the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) was passed. This law is known as the Superfund act. It taxed the chemical industry and used those revenues to investigate and cleanup abandoned chemical dump sites. Eventually, over 1200 superfund sites were discovered and studied nationwide. Over 90 of those sites are in California. Cleanup is very expensive and there is not enough money available to fix all sites at once. Still, over 300 sites have been cleaned up and removed from the list.

Today, chemical wastes continue to be generated in large quantities mainly by petrochemical industries, electronics manufacturers, metal fabricators and mining operations. But because of detailed environmental laws and regulations, the wastes are handled more responsibly. Before being placed in the ground either in a 55-gallon drum or in bulk, some are detoxified by chemical treatment, like making acid wastes non-acidic. Others are treated by adding chemicals to solidify them – so they can’t leak.


Despite that the USA has implemented laws and practices that manage hazardous chemical wastes more responsibly, the problem of hazardous wastes is a growing problem in emerging economies around the world. For example, China generates over 11 million tons of industrial hazardous wastes (Duan, Huang, Wang, Zhou, & Li, 2008). India’s growing industrial economy is faced with the same hazardous waste management problems (Misra & Pandey, 2005).

Overuse of irrigation in hot, dry lands – salt buildup in topsoil

The main benefit of irrigation in arid lands is the ability to grow food in rain-starved areas. This is especially true in California’s San Joaquin Valley and Imperial Valley. It is also true in many parts of the arid southwestern United States including the panhandle region of western Oklahoma and northern Texas.

There are two main sources of irrigation water: 1) groundwater pumped to the surface; and 2) river water imported by way of canals. The difference between rain water and irrigation water is the amount of salt. Irrigation water contains salt. Rain water contains almost no salt (there are tiny amounts of chemical salts formed as some atmospheric gases dissolve in the rain water droplet). Generally, agricultural operations that rely on rain and use no irrigation have little trouble with salt buildup. But those areas are vulnerable to drought. Agriculture that depends on irrigation is less vulnerable to drought but is in danger of accumulating excess salts in the soil.

Here is how it works. A farmer distributes irrigation water across their land. Remember, the irrigation water is carrying a load of salt dissolved within. In arid climates, the water near the soil surface quickly evaporates. Evaporation takes away the water but not the salt. So, a small amount of salt is left behind in the soil. As this process repeats over several decades, the accumulated salt becomes so high that it is not possible to grow anything. In many cases, the salt can be seen covering the landscape which has become a sparkly white salt barren. The Food and Agriculture Organization of the United Nations reported in 1988 that the United States alone had over 32,000 square miles of salt affected soil.

Salty soils make it hard to grow plants because water tends to flow in the direction of the highest

concentration of salt. This is just a process of diffusion where substances spread out seeking uniformity of distribution. If a seed is planted in salty soil, the water in the seed will tend to move out of the seed and into the soil, seeking equilibrium. The seed will dry out and cease operations. Or if a mature plant is transplanted into salty soils, moisture in the plant will flow out through the roots and into the soil, instead of the other way around. This will cause the plant to dehydrate and eventually stop operations. Or if plants are growing in moderately salty soils, their roots will struggle to obtain moisture, and growth will take on a stressed appearance.

Salt buildup in Utah farmland irrigated with Colorado River water.

Farmers have learned that it is possible to prevent such salt buildup in the soil’s upper layers by forcing the accumulated salts deeper into the soil, below the root zone. They do this by using much more water than their crop needs. The excess water percolates deeper into the soil, carrying the salts with it. But this is very expensive in terms of water demands. Preventing salt buildup on high quality cropland is another challenge for farmers. One approach is to use sprinkler irrigation instead of flooding watering channels in row crops. Sprinkler irrigation is more efficient in getting the water to the roots, uses less water to do so, and therefore imports less salt onto the land. Another approach is the use of drip irrigation. This is best used for farms where plants are permanent


fixtures, such as apple orchards, orange groves or vineyards. Drip irrigation focuses the delivery of water, and reduces the total amount of irrigation water used, thereby reducing the salt accumulation in the soil.

Radioactive contamination

Probably the most frightening form of land spoiling is radioactive contamination. There are two main ways in which humans have spoiled the land with radioactive contamination: 1) atmospheric testing of nuclear bombs; and 2) accidents from nuclear power plants.

First, let’s go over the essentials of radioactivity and why it can be harmful to living systems. Some chemical elements are prone to be radioactive. This is because the nucleus of their atoms tends to be unstable. Uranium and plutonium are examples. This instability eventually leads to the ejection of a particle (protons, neutrons, or subatomic particles) or electromagnetic radiation from the nucleus. This is called radioactive decay, and it happens at different rates for different elements. This decay event is the “radioactive” property of the element. When the nucleus decays, the ejected particles and radiation possess high amounts of energy and can do damage to other atoms they come into contact with. Electromagnetic radiation that accompanies radioactive decay can include all bands of the spectrum, including light and very dangerous x-rays and gamma rays.

The rate of decay for any radioactive element often is expressed as the element’s “half-life.” Half-life is a statistical value that represents the time it takes for half of any mass of the radioactive element to decay. A shorter half-life means that the material is decaying rapidly. As a given mass of radioactive material decays, less and less of it is radioactive, making it less and less dangerous over time. All elements (and their isotopes) decay at different rates. For example, the half-life of Helium-6 is just under one second. But the half-life for Uranium-232 is about 69 years. And the half-life for Potassium-40 is 1.3 billion years.

The problem with radioactivity is that it can be harmful to biological systems. High energy radioactive particles and high energy electromagnetic radiation can break biological molecules apart. Like tiny little bullets colliding with atoms and knocking them off the molecule of which they are attached. This act of breaking

molecules apart is called, “ionization.” Radiation (either particle radiation, or electromagnetic radiation) that can cause ionization is called “ionizing radiation.” It’s the ionizing radiation that’s the scary part about radioactivity.

Over-exposure to ionizing radiation can cause things like sunburn (addressed earlier in this book). Sunburn is the outcome from the death of skin cells. The skin cells are killed by over-exposure to ultraviolet radiation. The ultraviolet radiation breaks important molecules apart inside the skin cells, ultimately causing cell operations to stop, and the cell fails. Ultraviolet radiation penetrates only a short distance into the body, on average, less than 2 mm. As a result, damage caused by ultraviolet over-exposure tends to involve the skin and eyes. Damage to collagen molecules in the skin, causes premature aging of the skin. In some instances, ultraviolet over-exposure can trigger skin cancers in various forms, including the deadly melanoma. The eyes also can be harmed by over-exposure to ultraviolet, which can degrade the lens resulting in cataracts.

Some forms of electromagnetic radiation can penetrate deeper into the body. For example, x-rays and gamma rays can pass completely through the body. Bones act as barriers to x-rays. As a result of deeper penetration, these forms of radiation can damage more organs, resulting in diminished performance and possible cancers.

The hazards associated with radioactive particles are a bit different. Radioactive particles can be taken into the body by breathing them in from the air, or ingesting food or water contaminated with radioactive particles. Once inside the body, radioactive particles can accumulate in pockets where they will continue to deliver a constant dose of radiation. For example, the thyroid gland tends to be a collecting place for iodine atoms. Iodine-131 is a radioactive form of iodine. The iodine-131 particles ingested by humans will concentrate in the thyroid gland. Once there, the iodine-131 will deliver its products of radioactive decay to the sensitive tissue of the thyroid gland, increasing the risk of gland failure and cancer. Iodine-131 is a by-product of nuclear fission and is produced in the reactors of nuclear power plants. Residents around nuclear reactor sites are given tablets (potassium-iodide) of the non-radioactive form of iodine, iodine-127. In the event of a release of radiation from the nuclear plant, residents are instructed to


take the potassium-iodide tablets. The surge of iodine into the body floods the thyroid gland with safe, non-radioactive iodine. If the person is soon exposed to radioactive iodine, the thyroid gland will reject the radioactive iodine because it has all the iodine it needs.

People began to have worries about exposure to radioactive particles in the 1950s. The American military had been testing atomic bombs in Alamagordo, New Mexico and the Nevada Test Site starting in the mid-1940s. Bombs were placed on a tower and detonated. The radioactive material making up the core of the bomb was dispersed high into the atmosphere in the iconic mushroom-shaped cloud. Winds dispersed the radioactive dust across North America and around the world. Following America’s lead, four other countries started conducting their own atmospheric tests of nuclear bombs, including the Soviet Union, France, the United Kingdom and China. Atmospheric testing of America’s extremely powerful hydrogen bombs moved to the Marshall Islands in the tropical South Pacific. Because of worldwide concerns over radioactive fallout, most countries (including the USA) stopped atmospheric testing of nuclear bombs in 1963. The final atmospheric test was in China in 1980. Instead of detonating test bombs above ground, bombs were detonated underground until the late 1990s.

Atomic bomb test in Nevada, 1951.

In 1945, the United States military dropped atomic bombs on the cities of Hiroshima and Nagasaki, Japan. The bombs killed tens of thousands of people instantly. In the aftermath, many deaths amongst survivors were attributed to radiation exposure from the bomb events themselves and from continued exposure to radioactive particles that covered the bomb sites. Cancers, including high

rates of leukemia (a bone marrow cancer) amongst the locals have been attributed to radioactive remnants of the bombs.

Aside from making bombs, nuclear technology involves many other areas of human enterprise including medicine, space sciences, and earth sciences. One application that has the potential to spoil the land is nuclear power generation. Well, not just “potential” to spoil the land, because notable accidents at two nuclear power plants have done it.

The accidents at the Chernobyl and Fukushima nuclear power plants spoiled the surrounding lands with radioactive materials. Both plants had completely different designs, and both had accidents started by completely different causes. But both had similar outcomes including: 1) loss of control of the reactor(s); 2) exposure to the atmosphere of large masses of highly radioactive fuel; 3) release of large amounts of radioactive particles to the atmosphere; and 4) contamination of the surrounding lands with dangerous amounts of radioactive fallout.

Early in the morning of April 26, 1986, operators at the Chernobyl nuclear power plant were conducting a test of the reactor. They wanted to determine how the reactor would behave while operating at extremely low power. They were surprised to discover that the reactor would EXPLODE! The test produced a spike in core temperature, causing the fuel rods to explode. The increased heat produced a massive buildup of steam inside the reactor building. The steam pressure finally burst the walls and ceiling of the reactor building. This blew off the top of the reactor building and exposed the burning graphite nuclear fuel to the atmosphere. The plume of smoke from the reactor fire was carried northwest by winds. It contained so much radiation that it set off radiation alarms at a nuclear power plant in Sweden, over 600 miles (1000 km) away. The fire burned for about two weeks before being covered by sand. Volunteer workers (wearing no protective equipment) would run up a ramp carrying a sandbag and drop it onto the reactor. Helicopters hovered over the reactor and dropped loads of sand. Over 40 of these volunteers eventually died from acute radiation poisoning or thyroid cancer. Thousands of cancer cases in the surrounding areas have been attributed to the incident. The nearby town of Pripyat (population: 49,000) was not


immediately evacuated despite that many residents there were displaying symptoms of acute radiation exposure. Finally, two days after the onset of the accident, Pripyat was quickly evacuated and remains an unoccupied ghost town today. Following the accident, Soviet authorities established the Chernobyl Exclusion zone. The zone is a circular area around the plant with a radius of 18.6miles (30 km) and covers an area of about 1000 square miles (2600 square km). The public are forbidden free access to the zone which remains highly radioactive.

Chernobyl nuclear power plant in 2009. Reactor now encased in concrete sarcophagus.

Circa 2005, the town of Pripyat, Ukraine (foreground) remains an abandoned ghost town. The Chernobyl nuclear power plant is in the background.

On the afternoon of March 11, 2011 a powerful earthquake struck off the east coast of Japan. The shaking was so severe, that the Fukushima Daiichi nuclear power plant was scrammed by automatic control systems. “Scramming” a reactor means to shut it down by beginning the process of reducing heat output and cooling down the reactor core. It is not possible to simply flip a switch and shut off a

nuclear reactor. The reactor core is made up of many tons of radioactive fuel rods that generate heat in a controlled environment that regulates the rate of nuclear fission. Once started, it may take weeks to gradually build up to optimal operating temperatures. Once scrammed, it may take weeks for the reactor to cool down. Scramming a reactor starts a series of operations to secure the reactor and put it in “safe” mode. Once scrammed, the plant no longer generates electricity and must be powered by emergency diesel generators located on site. Following the earthquake, this is what happened, and all went according to plan. But then something followed that was not in the plans… tsunami.

A tsunami is a sudden change in the tidal height caused by an earthquake at sea. Sometimes called tidal waves, tsunamis are essentially shock waves that travel through the water at 500 miles-per-hour (800 km/hr). The earthquake created a large tsunami that struck the eastern coast of Japan. Since the Fukushima nuclear power plant was located on the eastern coast, it was vulnerable to this tsunami. Fifty minutes after the earthquake, the tsunami arrived at the Fukushima plant. Cresting just before striking the plant, it was nearly 50 ft (15 m) high and easily swept over the plant’s 19 ft. (5.7 m) seawall. Water from the wave flooded basements at the plant containing emergency diesel generators, causing the generators to shut down. Since the reactor must be constantly cooled, even during a scram, and since the cooling water must be supplied by pumps, and since the pumps were now without power, the reactor was not being cooled. When that happens, water in the reactor vessel boils. At such high temperatures, hydrogen gas starts to form, some of which was getting vented into the reactor’s containment building. The problem with hydrogen gas is that it is very explosive. Think of the Hindenburg zeppelin accident. The Hindenburg burst into a disastrous fire following a spark of static electricity while trying to dock. The airship was filled with hydrogen gas. Operators at Fukushima were worried about such an explosion in the containment buildings at Fukushima. In addition, without cooling, the reactor core will get so hot that the fuel rods will melt and collect as a mass of molten metal at the bottom of the reactor vessel. If melting is not stopped, the molten mass could eventually melt through the reactor vessel and drop out onto the


floor of the containment building. The multiple scenarios that would follow, are all disastrous.

There was another problem and it had to do with spent fuel rods that were being stored on site. Even used fuel rods require constant cooling because they continue to generate heat. The incident came to a head when hydrogen explosions in several of the reactor buildings blew out walls and rooves and exposed uncooled, spent fuel rods to the atmosphere. Radioactive debris from the explosions littered the plant site. The good news was that the reactor vessels themselves were not breached. With the help of heroic firefighters, operators were able to restore cooling to the reactors and spent fuel rods.

Two plant workers died of physical trauma and blood loss during the accident. And unlike Chernobyl, emergency personnel were better protected, with safety gear, and exposure limits. Presently, there is nothing remarkable to report on the extent of health effects from radiation exposure by plant workers and resident nearby. The current exclusion zone includes all land within 12 miles of the Fukishima plant. Authorities estimate the land will be uninhabitable for a minimum 20 years.

Fukushima nuclear power plant during 2011 disaster.

There have been many other incidents at nuclear power plants although not as disastrous as Chernobyl and Fukushima. In 1979, the Three Mile Island plant in Pennsylvania experienced a partial meltdown in one of its reactors. No significant radiation releases were reported, but the reactor was a total loss. In 1975, a worker at the Browns

Ferry nuclear power plant in Alabama used a lit candle to check for air leaks in walls leading out of the cable room beneath the control room. The candle flame ignited foam sealant and started a fire that nearly caused a complete loss of control of the reactor.

In light of these incidents, the nuclear power industry has shown that it has learned lessons from them. The current trend in nuclear power plant design is to make them simpler and safer. For example, a new Westinghouse design places a large reservoir of emergency cooling water on top of the containment building (Westinghouse, Inc., 2012). In case of emergency shutdown, this water can flow by gravity into the reactor vessel. No pumps or electricity is needed. Seems like a good design. But like all the other “good designs” before, only time will tell.

Impacts from Clearing, occupying, and spoiling the land

Habitat loss, reductions in biodiversity.

Over the last 1000 years, humans have rapidly spread out across the planet and our demand for land continues to grow. The general pattern is to clear the land of natural vegetation, then prepare the bare land to support the intended activity, such as farming, cattle grazing, or a new mini-mall. Regardless of the human land use, the pre-existing natural habitat is now gone. That means that the pre-existing natural populations of plants, animals, fungi, and microorganisms also are now gone. If this kind of activity occurs on a large scale and over an extended amount of time, the landscape can be utterly transformed from one rich in natural habitat, into one absent of natural habitat.

I am going to highlight several geographic regions that have experienced remarkable habitat loss.

Madagascar

Madagascar is the world’s fourth largest island, located off the southeast coast of Africa in the Indian Ocean. The island has experienced significant habitat loss due to large scale deforestation, timber harvesting and cattle grazing. Following land clearing efforts, the remaining land was poorly managed such that the bulk of the island now suffers from severe topsoil erosion.


Starting with easily accessible land near the coastlines, humans steadily worked their way inland, clearing the land along the way. Today, about 90% of the island has been cleared of native vegetation. The remaining 10% consists of a thin

strip of mountainous terrain that forms a kind of forested spine along the island’s eastern side.

Soil erosion following deforestation, Madagascar.

Madagascar is home to many endemic species. The term, “endemic,” means a species that exists in one geographic location and nowhere else. For example, lemurs are endemic to Madagascar. The island is home to about 100 species of lemurs. If you want to see lemurs in the wild, you must travel to Madagascar. You won’t find lemurs in Africa or anywhere else. Most lemurs are arboreal (arbor, refers to tree), meaning they tend to live their lives up in the trees. Since humans began settling on the island about 2000 years ago, more than a dozen species of lemurs have become extinct. And continuing trends of habitat loss on the island are

resulting in population declines on many remaining species. And not just lemurs.

Other endemic species on Madagascar include most of the world’s species of chameleons, a cat-like predator called a fossa and many enchanting plants including the bizarre baobab tree. About 90% of the species of plants and animals on Madagascar are endemic, and nearly all are experiencing significant impacts from habitat loss and habitat degradation.

Ring-tailed lemur and baobab trees, Madagascar.


What can you do to help Madagascar?

• Avoid buying plants or pets from Madagascar. They are most likely being traded illegally. Help kill the market by not participating in it.

• Support organizations that are working to advance conservation efforts in Madagascar, like the World Wildlife Fund, or the IUCN for example.

• Recycle paper. There is still much deforestation going on in Madagascar. Much of this timber is headed to paper mills. Reduce demand for this wood by recycling more.

• Take a trip to the San Diego Zoo or the San Diego Safari Park – instead of Disneyland. Your ticket fees help fund conservation efforts. Also, you will have a chance to see and connect with many beautiful endangered species.

Borneo

Borneo is the third largest island in the world. Its land and surrounding waters are controlled by three different countries: Indonesia, Malaysia, and Brunei. The equator crosses nearly at mid-point, making Borneo a definitive tropical island. As you might expect, with rapid human population growth on the island and the expansion of commercial exploitation of the island’s natural resources, natural habitat is quickly disappearing. Following the pattern seen in Madagascar, humans first developed the island along the coasts, and then steadily moved inland. This development pattern has created a ring of habitat loss around the island, leaving a core of natural habitat at the island’s center. As in Madagascar, commercial timber harvesting accounts for most of the recent habitat loss. But unlike Madagascar, much of the deforested land has not gone to waste. Instead, much of it has been converted to plantations, especially palm oil plantations. However, the trending problem is that the growing palm oil industry is now driving deforestation in Borneo. That is, large tracts of virgin rainforest are being intentionally cleared away specifically to make room for palm oil plantations. The result is the expanding loss and fragmentation of habitat for the indigenous species of Borneo.

Palm oil plantations following deforestation, Borneo.

Borneo is home to many magnificent endemic and rare native species which now are experiencing significant impacts from habitat loss. For example, the Bornean Orangutan is a large, red-haired great ape that occupied mature forests throughout the island. Other arboreal species include many forest-dwelling tropical birds and nearly 100 species of bats, many of which are endemic. The endemic and endangered Borneo elephant also is in decline as its native forest habitat is rapidly disappearing.

Orangutan.

What can you do to help Borneo?

• Avoid using palm oil in your cooking. Although it may be cheap, it is high in trans fats and saturated fats – which are known to be unhealthy fats. Use healthier and less environmentally damaging cooking oils like canola oil, olive oil or peanut oil. And use less oil


overall by using nonstick frying pans and nonstick cooking oil sprays.

• Support companies who have made public commitments to use only deforestation-free palm oil in their products, like Nestle, Unilever, L’Oreal and Mondelez.

• Avoid products from companies that have made no commitment on deforestation-free palm oil, like Kraft, Clorox and nearly every fast food chain in the USA. (Union of Concerned Scientists, 2014).

• Check the ingredients for the packaged food you buy at the grocery store. Avoid packaged food that contains palm oil. Choose alternative brands that contain substitutes such as vegetable oil or canola oil.

• Support reputable organizations actively engaged in conservation efforts in Borneo, like the World Wildlife Fund’s “Heart of Borneo” project.

• Recycle and reduce demand for paper from deforested trees. Paper is a GLOBAL commodity.

Kenya

Kenya is found in east equatorial Africa. A country of diverse terrain, it is the home for some of the most emblematic African wildlife species including the African elephant, lions, cheetahs and many species of antelope and gazelles. Because of its remaining pockets of distinctive African wildlife, Kenya is a popular ecotourism destination.

Because of high human population growth, Kenya has experienced rapid habitat loss. However, Kenyans have made significant attempts to prevent soil erosion, and restore deforested land to productivity. To reduce erosion, there is extensive use of terraced slopes.

Terraced slopes reduce erosion following deforestation, Kenya.

As a result of habitat loss, many populations of wildlife within Kenya are in decline, and some are in danger of becoming extinct. Examples of endangered species include the western black rhinoceros (extinct in 2011), African wild dog, and Grevy’s zebra. Vulnerable species include the African elephant, several species of bats, cheetah, lion, and hippopotamus. Kenya is nearly fully developed. Wild lands now only exist within a network of 35 parks and reserves maintained by the Kenya Wildlife Service.

African wild dog, and cheetah.

What can you do to help Kenya?

• Support organizations engaged in wildlife conservation efforts in Kenya such as the Kenya Wildlife Trust, the Nature Conservancy, and the San Diego Zoological Society.

• Support organizations that are helping Kenyans develop sustainable farming and forest harvesting methods, like Farm Africa USA, or NURU International, Kenya.

• Avoid purchasing artifacts made of elephant ivory, leopard skin or cheetah skin.

• Take a fabulous wildlife vacation to Kenya. Eco-tourism provides a substantial source of funds that support conservation efforts, and gives incentives to the locals to protect their wildlife habitats.

Rondonia, Brazil

Rondonia is a western state in Brazil. Naturally, an area covered in tropical rain forest. But this area experienced a fiery transformation at the hands of human settlers. In the early 1970s, the Brazilian government built a road deep into the Rondonia frontier and invited Brazilians to settle there. The government offered free or extremely cheap land that the settlers could claim as homesteaders.


Hundreds of thousands accepted this inviting offer. The human population of Rondonia grew from about 100,000 in 1970 to its present 1.75 million. As part of the bargain, homesteaders were obliged to clear the forest from a portion of their property, build a house, and use the land in a productive way.

Initially, settlers tried farming the land with row crops. They soon discovered that the thin tropical rain forest soil provided little mineral nourishment and crop yields were miserably low. So, rather than farm the land, most settlers became ranchers and now run small herds of cattle. Today, satellite images show that the overwhelming majority of cleared land in Rondonia is dedicated to cattle grazing.

Cattle ranches with telltale corals and water holes, Rondonia, Brazil.

Although settlers were legally restricted to clearing only 20% of their land, most have significantly exceeded this limit. 50% to 80% clearing is the norm. Today (2018) about two thirds of the original rain forest of Rondonia is gone. And what remains is highly fragmented.

What is most striking about Rondonia is the speedy transformation of the district. This was an aggressive, well-planned, industrial scale and extremely efficient deforestation project. The precise geometric branching pattern of the region’s roads expresses this exquisitely.

Massive deforestation of Rondonia, Brazil.

Due to the scale of habitat destruction in Rondonia, it is not surprising that many tropical rain forest species are in decline in the region. Such species include Rondon’s marmoset, and the Rondonia bushbird. And given the region’s connection with the larger Amazon rain forest, many other species are in retreat, including the jaguar, howler monkey, ocelot, scarlet macaw and Harpy eagle.

Jaguar.

What can you do to help the Amazon rain forest?

• Reduce your beef intake. Aside from substantial health benefits, reduced demand for beef is an important disincentive to cattle ranchers in Brazil and elsewhere. About 2/3 of deforested Brazilian rainforest is converted to cattle grazing land. Brazil is one of the world’s biggest beef exporters. Help stop that by eating less beef.

• Recycle paper as much as possible. Use dishtowels more and paper towels less.


• Avoid purchasing furniture made out of rain forest woods like mahogany, ebony and rosewood.

• Support organizations performing conservation efforts in Amazonia, like the Nature Conservancy and the Rain Forest Action Network.

Europe and the United States

Europe and the USA have experienced large habitat losses due to ever increasing human populations. In Europe, the establishment of national parks is a relatively recent phenomenon. Depending on the particular country, wilderness areas make up 1% to 3% of the country’s total land area. In the USA, wilderness remains present in the country’s 59 national parks. In addition, the Bureau of Land Management and Department of Forestry manage large areas that remain largely wilderness. Still, with continued population growth and growing resource demands, the amount of wilderness continues to decline, and what remains sometimes becomes highly fragmented.

For example, let’s consider the Los Angeles basin in southern California, consisting of Los Angeles County and Orange County. Before the arrival of European settlers, this generally flat terrain was covered with chaparral and coastal sage scrub habitat. Indigenous peoples made their living mostly as hunter-gatherers. Then starting in the 1700s, European settlers claimed ownership of the land and set fire to it, clearing away the shrubbery to make room for their crops and cattle. Remnants of those natural habitats survive in hilly, hard-to-develop terrain such as the Santa Monica Mountains, Hollywood Hills, and Santa Ana Mountains. Species whose numbers have fallen include the California gnatcatcher (endangered), Mountain Lion, and Bobcat.

Wood Canyon in southern Orange County, CA.

California Gnatcatcher.

What can you do to help the USA?

• Demand thorough environmental impact reports (EIRs) for all proposed land development projects.

• Attend public hearings for land development projects in your community and voice your concerns.

• Demand habitat restoration to mitigate unavoidable habitat loss from land development.

• Support the California Department of Fish and Game and the US Fish and Wildlife Service efforts to protect habitat and endangered species.

• Visit state and national parks and respect the wilderness within.

• If you’re a deer hunter in California, use nonlead bullets.

• Support conservation efforts to establish and maintain wildlife corridors in suburban settings.

• Heed warnings about fire danger during fire seasons.

Local impacts.

Habitat fragmentation

Aside from quantity of lost land area, the pattern of land loss can make a big difference. If a bloc of land is crisscrossed by roads, or if patches of it are developed, the land bloc becomes fragmented. Instead of existing as one large contiguous bloc of habitat, the habitat has become subdivided into smaller fragments. In the worst kind of fragmentation, tiny parcels of natural habitat have lost all interconnectedness and exist as small isolated islands.

Fragmentation is bad for natural populations because as the habitat is reduced, natural populations decline, due to reduced availability of space and resources. Smaller populations are more


susceptible to local extinction. If fragments are isolated, then the remaining populations are extremely vulnerable to catastrophic events such as fire or drought --- their means of escape and rescue being cut off.

Fragmentation of habitat can disrupt historic migration routes for many species. On a fragmented landscape, migrating animals are confronted with hazards such as highways and canals, or outright barriers, like fences.

Edge Effect

When humans develop an acre of land, the overall impact to the natural habitat is greater than one acre. That is because the activities occurring in that acre also disturb the nearby surroundings. This disturbance is called the “edge effect.” For example, a 100 acre plot of natural land is cleared and a new housing development is built. Human influence extends beyond the outer borders of this development. Domestic cats explore the neighborhood’s natural surroundings, taking up permanent residence thereby establishing a population of feral cats. The noise of human activities like leaf blowers and car alarms can be too discomforting for many native species. Fire suppression perimeter clearing creates a kind of dead zone around neighborhoods in fire-prone areas.

Characteristics of species that are particularly vulnerable

Not all species are equally vulnerable to habitat losses. Some are more vulnerable than others, depending on their current circumstances or according to the way they interact with the environment.

Species whose populations are critically small.

Depending upon the species, there is certain minimum population size that must be exceeded for the population to persist. This minimum population size is a number called the “minimum viable population.” If the population drops below this number, then the population will continue to decline, eventually becoming extinct. For most birds and mammals, the minimum viable population ranges between 100 to 500. For less behaviorally flexible animals, the MVP is in the 1000s. For example, the California condor population dropped to less than 50 in the 1980s. They were in imminent danger of extinction. In the late 1980s, a captive breeding program was implemented that collected all remaining 22 condors from the wild, protected them and nurtured a successful reproductive return.

By the end of 2016, there were 446 California condors. And 276 of them were alive in the wild. Despite this remarkable success story, there continue to be problems. One big problem was the discovery of high amounts of lead in the blood of condors found dead in the wild. The condors died from lead poisoning. But where was the lead coming from? It turns out that the lead came from the lead bullets in discarded animal remains left behind after deer hunters field-dressed (gutted) their kills. Condors would happen along later and eat the guts, bullets and all. In 2008, a California state law came into effect that requires deer hunters to use nonlead bullets. Hunters now use bullets made of copper instead of lead. As a result, lead levels in wild California condors has dropped significantly, as has their mortality from lead poisoning.


California condor.

Some species may have large numbers collectively in patches, but may have small isolated populations that are at risk. The Arabian Oryx is another good example. In the 1970s, it became extinct in its natural habitat whose final range consisted of parts of Saudi Arabia. Despite the disappearance of the oryx in the wild, many zoos still had living individuals. Many of these were organized into a successful captive breeding program in the 1980s. Offspring from this program were eventually transported across the globe to the Middle East and reintroduced into the wild. They are not out of danger yet as their numbers in the wild are only about 1000 and their status is classified as “vulnerable.”

Arabian Oryx.

Species that have very specialized habitats

Some species have very narrow ranges of behavioral flexibility, and they suffer if their “preferred” habitat changes or dwindles. Speaking of narrow, the Light-Footed Clapper Rail is a secretive little marsh bird about the size of a small hen that lives in Southern California salt marshes.

It is compressed laterally like a flea is flattened on the sides. The bird’s narrow frontal profile allows it to easily walk through the thick marsh grass that forms the clapper rail’s principle habitat. Rarely

venturing beyond the cover of the marsh grasses, this bird is seldom observed even by the most avid naturalists. This bird is endangered mainly because most of its coastal salt marsh habitat has disappeared, developed into harbors, or filled in for seaside urban developments. About 90-95% of the original coastal marshlands of southern California are gone. Despite ample time to explore alternative habitats, the Light-Footed Clapper Rail has not adjusted, and so, it remains utterly dependent upon its dwindling specialized salt marsh environment.

Another species that has a somewhat narrow range of environmental tolerance is the California gnatcatcher. This tiny bird lives mainly in the coastal sage scrub habitat. Its kitten-like mewing vocalizations bring a delightful cheeriness to its scrubby surroundings. The coastal sage scrub habitat occupies / occupied much of the low coastal plains of southern California. This land was easily developed and was replaced by the sprawling network of cities that now dominate the region. It has been estimated that 70-80% of the original coastal sage scrub is gone. As a result, the population of California gnatcatchers has dropped to such low numbers that it is classified as “endangered.”

Migratory species

Species that undergo seasonal migrations have special demands on the natural environment. They need suitable habitat at both ends of their

Clapper rail.


migration route, and they need suitable environments along the way. In addition, migrating animals need freedom of movement. That is, they need to make their trek without being blocked by fences, highways, dams, and human settlements. Barriers of this sort are a very big problem for animals travelling on foot or swimming up rivers.

For example, the nearly continuous migrations of the wildebeests and zebras of the African Serengeti plain of Tanzania and Kenya involve large herds of grazers. But with the recent rapid conversion of thousands of small plots of land from open savannah to fenced-in farmland, there are two problems for the travelers: 1) their historical routes are blocked (including blocked access to strategic water holes); and 2) there is less food available for them. As a result, the wildebeest and zebra populations are in decline.

Wildebeest and zebra on the Masaai Mara, Kenya.

Many species of salmon in the northwestern United States have experienced episodes of significant losses in recent times. Most salmon hatch in the headwaters of major rivers (like the Columbia River in Oregon) then migrate down the river to the Pacific Ocean. After spending up to five years feeding and maturing in the ocean, and following a scent trail, adult salmon return up-river to their place of origin to reproduce. Most of the problems that salmon face happen in the river. Dams block salmon migration up and down the river. Installations of fish ladders help many salmon circumvent dams. Salmon prefer cold waters. But the warm waters in dam’s reservoirs can support more salmon predators, and make salmon more vulnerable to disease. Inland along the river, timber harvesting clogs the river with silt and debris, severely degrading the river habitat. In addition, the loss of shade along the river causes water

temperatures to climb, further stressing salmon physiology.

Fish ladder on the John Day Dam, Columbia River, USA.

Species that are a threat to human commercial operations

Many predatory mammals are at risk of extinction because they naturally interfere with human enterprise, like raising cattle, for instance. Cheetahs in Africa and the Middle East are a good example. Although the total numbers of cheetahs worldwide may be more than 10,000, many small, isolated populations are dropping because of loss of habitat. As farmers and cattlemen encroach into cheetah hunting grounds, they replace the cat’s natural prey of gazelles and wild boar with docile farm animals. Faced with hunger and dwindling wild prey, cheetahs hunt domesticated livestock. Farmers and cattlemen respond by shooting cheetahs.

Very similar stories occur all over the world. In Rondonia, jaguars are shot to protect farm animals. In the United States, grizzly bears and wolves were hunted into regional extinctions, a mass killing sponsored by bounties posted by farmers and cattlemen. Grizzly bears and wolves used to roam the entire lower 48 states. The California state flag prominently features a grizzly bear. But they are now extinct in California and over most of their former range in the lower 48 states.


Cattlemen capture a gray wolf in Wyoming, USA.

Species that yield big money

Some species are more valuable dead than alive. For example, the Whooping Crane was hunted and killed nearly out of existence because their long and luxurious tail feathers provided that perfect final touch for mid-20th century fashions. In Africa, mature elephants continue to be hunted (illegally) for their fine ivory tusks. Black and White Rhinos are killed for their “horns” which are used for dagger handles or ground down to make faux medicinal powders. Any cat with spotted fur is trapped or shot, their skins sold for coats, or hats. Gorillas are killed, their heads sold as trophies and surefire conversation pieces; their hands and feet crafted into novelty ashtray holders. Beavers and otters are trapped for their fur.

Male black rhinoceros with calf.

Biological and ecological impacts from such losses. Gene losses.

The question that inevitably arises following this presentation of habitat and species loss is, “Why should we care?” Fair question. We should care for many reasons.

First we should care for purely practical reasons. Natural wilderness provides many services that enhance the local and global environment. And these services are free. For example, photosynthesizers on land and in the oceans produce molecular oxygen, and they suck down CO2, which has been increasing rather rapidly of late. Terrain occupied by a teeming ecosystem absorbs rain water, preventing flooding and mudslides during storms. Honeybees living in the wild transport pollen across the land, visiting every flower. Underground, a collection of roots, worms, insects, fungi and bacteria churn the soil, speeding the return of vital nutrients and opening pathways so that oxygen can penetrate to the deepest roots below.

There is valuable genetic variety in wild species. Agricultural scientists cross breed different wild varieties of a species to produce new combinations of features better suited for changing environments. Seed banks store thousands of varieties of rice, for example, because the genetic resources within have enormous value to future food production. Although scientists are experimenting with the technology of designing genes from scratch, it is far easier and much cheaper to mix existing genes. Biochemists working on new medicines gain inspiration from odd but bioactive chemicals in wild things. Ethnobotanists scour the world’s forests, deserts, oceans and muddy ponds in their hunt for natural chemicals that can help cure disease. For example, the foxglove flower produces a substance called digitalis that is used to treat irregular heartbeats. The compound, atropine (belladonna), comes from the Deadly Nightshade plant and is used as a muscle relaxant. Roots from the Indian snakeroot plant contain the chemical, reserpine, that is used to reduce heart rate and blood pressure. And the bark of the willow tree contains salicylic acid, the essence of aspirin. Despite the high technological façade of our modern western pharmacology, medicine inventors still rely on nature for insight and inspiration.


Foxglove flower, and Deadly Nightshade. Both are sources of powerfully useful medications.

Second, we should preserve natural environments and species for ethical reasons. The ultimate question we must ask ourselves is, “What kind of species do we want to be?” Humans have more power than any species that ever inhabited this place. How do we choose to use this power? Does it matter to us now? Will it matter to our descendants? Do we even care? I think it is important for every human individual to consider the ethical and moral implications of their own existence and their individual impact. Especially in prosperous economies like the USA where affluence affords us the privilege and opportunity to reflect on our deeper relationships with the world around us. True, you didn’t ask to be brought to planet Earth. But now that you are here, what kind of a person do you want to be? What kind of society do you want to cultivate? What kind of world do you want to live in? You are not an automaton. You do have free will to make choices. Please deliberate thoughtfully, choose and act.

Ways in which humans attempt to reduce or offset impacts to species diversity

In the face of growing threats to many species around the globe, humans have done many good things to help protect species. First, it important to identify which species are at risk. The International Union for Conservation of Nature (IUCN) is an independent international organization that, as part of its conservation efforts, categorizes species according to the degree of risk they face. Their categories of conservation status have become the accepted world standard, and are listed below in decreasing order of risk.

Conservation status

1. Extinct 2. Extinct in the Wild 3. Threatened 4. Critically Endangered 5. Endangered 6. Vulnerable 7. Conservation Dependent 8. Near Threatened 9. Least Concern

Dedicated work to save species and whole ecosystems is done by many other conservation groups including the World Wildlife Fund, and the Nature Conservancy. These organizations raise money through private donations. Despite millions of dollars raised every year, there is one frustrating reality – there is not enough money and resources to save every species. So, conservation organizations must choose where their limited resources will produce the most fruitful outcome. As a result, the concept of a “Biodiversity Hotspot” was developed by British ecologist, Norman Meyers. A Biodiversity hotspot is a geographic region that has the following general characteristics: 1) It has high species diversity (many species); 2) It has high endemism (many endemic species); and 3) it is under threat from human activities. Once a biodiversity hotspot is identified, the overall strategy is not to just try and protect several species, but to conserve the entire ecosystem. Often this strategy is implemented by establishing an ecological preserve. If the land is owned by the government, conservation organizations will advocate for the establishment of a state-run park or preserve. If the land is privately held, organizations will attempt to purchase the land, after which, the organization will steward the protected land. Sometimes, this involves paying armed park rangers to ward off or capture poachers.

Biodiversity hotspots.


In some cases, the numbers of species in the wild are so low (below the minimum viable population), that the remaining individuals must be captured and protected in a safe environment. Once secure, a captive breeding program gradually helps bring numbers up. In addition, careful plans are made for the ultimate reintroduction into the wild. Examples of species benefiting from these programs include the California Condor, Arabian Oryx, Tasmanian Devil, Black Rhinoceros, and White Rhinoceros.

Similar tactics are taken for endangered plants. Botanic gardens around the world are safe repositories for many plant species that are declining in the wild. There are hundreds of seed banks around the world that warehouse the precious seeds of endangered and non-endangered plants. The largest seed bank is the Millennium Seed Bank Project in England where seeds from about 10% of the world’s wild plants are kept in frozen vaults. The Svalbard Global Seed Vault on a chilly Norwegian island is designed to keep seeds safe during a global calamity such as a global nuclear war.

Governments also are taking part in conservation efforts. The USA and many of its states have special laws dedicated to managing wildlife resources. For example, the National Park Service was established in 1916 with the goal of creating and managing the country’s most remarkable wilderness. Yellowstone National Park was the first, followed by 57 other parks and hundreds other protected parcels. Congress passed the Endangered Species Act in 1973 with the goal of identifying and protecting wild species. The U.S. Fish and Wildlife Service, and the California Department of Fish and Game enforce regulations based on this law.

Individual citizens also help conserve endangered species. By making informed choices in the things they buy, consumers shape market conditions. If consumers reject ivory art (which they should), the market for elephant tusks declines, as does the financial incentive to kill elephants. Much of the money paid for a ticket to the San Diego Zoo goes to the San Diego Zoological Society which funds conservation efforts worldwide. Or donating directly to a conservation organization like the Nature Conservancy provides funds for purchasing and protecting wild lands around the globe.

Conclusion

Human beings are by far the most successful species that has ever lived on Earth. We have dispersed across the land and now control enormous stretches of it. We have used science to develop new technologies that help us prosper in the harshest environments. We build special housing or fabricate special clothing to keep us secure, warm, dry and busy in all kinds of environments. We have exploited the living resources of the planet to improve our standard of living.

In the last 200 years, our species has experienced an explosion in numbers. As of early 2018, there are over 7.6 billion people in the world. Each individual has a right to exist and thrive. And every individual requires resources from the Earth: living space, food, water. We are a species of trade. We are willing to exchange our time and effort for goods and services provided by others. The marketplace is a unique human invention that offers opportunities, rewards and profit. Humans have embraced the marketplace so vigorously that it has grown exponentially – seemingly without limits.

But we have learned that there are limits. There was only a limited amount of virgin forest in Borneo. But much of it has been cleared to make room for palm oil plantations. As a result, Orangutan populations on Borneo are declining. There are limits to the amount of unfragmented wilderness. Rapid development in Rondonia, Brazil has expressed little concern for this. The rain forest that used to exist there has been aggressively developed in a “textbook” case of fragmentation. The native species that previously lived there are in decline, including the jaguar and bushbird.

There was only a limited amount of topsoil in Madagascar. Much of it is lost, washed into the sea because of irresponsible, but very profitable harvesting of timber.

There was only a limited amount of industrial waste that the ground in Niagara Falls, NY could process. But the Hooker Chemical Company filled the Love Canal with it, and the nearby residents suffered.

There is only a limited amount of radiation living things can tolerate. But the Chernobyl and


Fukushima nuclear power plants continued to operate despite warnings of potential disaster.

There was only a limited amount of industrial waste that could be dumped into the Cuyahoga River in Ohio. But factories continued to discharge their wastes into it even after the river caught fire several times.

There is only a limited amount of emissions that can be released into the air before it becomes toxic. But cars, power plants and factories continue to pollute the air of Beijing, China.

There is only a limited amount of CFCs that can be released into the air before the stratospheric ozone layer is degraded. But refrigerators, air conditioners and industrial operations around the world continue to produce and release ozone-destroying CFCs.

There is only a limited amount of CO2 that can be emitted into the atmosphere before the planet’s temperature starts to rise, and before the oceans begin to acidify. But growing economies around the world are driven by greater demands for fossil-fuel-produced energy and fossil-fuel-burning transportation.

There is a limit to how much temperature gain humans and other animals can actually tolerate. Combined with increasing climate temperatures and accompanying increases in relative humidity, large parts of the planet now occupied by humans could become uninhabitable.

The problem is that humans are victims of their own success. Our brains are wired to seek and acquire resources. Shopping gives us pleasure. So does making money. But these short-term gratifications come with costs that we do not directly perceive. When buying a ream of paper for our home printer, we don’t perceive the loss of trees in Malaysia from which the paper was made – and the accompanying loss of habitat for gibbons.

Despite our inherent inability to instinctively respond to long-term environmental threats, there is hope. When things get bad enough, we are able to perceive the limits of our environment. In such cases, we have demonstrated a remarkable collective will to act. For example, in the 1960s when smog got so bad in American cities, millions of people complained and wanted it to stop. The Clean Air Act was passed in 1970. Since then the air has steadily improved. When rivers were being

filled with toxic wastes, millions of people complained and wanted it to stop. As a result, the Clean Water Act was passed in 1972. Since then, water quality in rivers has greatly improved. In similar fashion, many other environmental laws were passed in the USA and many countries in a successful effort to reduce environmental degradation. Humans have demonstrated that along with the toys and luxuries that mark a high standard of living, we also want a reasonably clean environment. And we are willing to pay for it.

In addition, we have demonstrated a moral concern for other species on the planet that are at risk due to our growing population and economic development. Millions of people support organizations like the World Wildlife Fund, the Nature Conservancy, the San Diego Zoological Society and many others. Our financial support has helped create millions of acres of protected wilderness, fund game wardens in parks ravaged by poachers, and develop captive breeding programs for the world’s most endangered species.

The special challenge for all of us is to remember to connect to our natural world – to remember that we are utterly dependent upon it – that all the stuff we want to buy was made from resources in our natural world –that despite that we are constantly urged by commercial interests to perceive our world only in terms of shopping opportunities, there is much more to our lives than shopping and consumption. We can make informed, responsible and wise choices that reduce our environmental footprint. Like driving a fuel-efficient car and consuming in a less wasteful and ostentatious manner. It’s not hard to do, but it does take concentration because of all the shiny distractions to do otherwise.

Planet Earth is a remarkable place and you have a few short years to experience it. I urge you to get out and discover the richness of the natural world you inherited. Now that you have read this book, perhaps you have gained a greater technical and historical understanding of it. Please enjoy it. Respect it. Love it.


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Image Credits

Earth at night http://earthobservatory.nasa.gov/Features/NightLights/ http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=79765 NASA Night Lights 2012 Credit: NASA Earth Observatory image by Robert Simmon, using Suomi NPP VIIRS data provided courtesy of Chris Elvidge (NOAA National Geophysical Data Center). Suomi NPP is the result of a partnership between NASA, NOAA, and the Department of Defense. Caption by Mike Carlowicz. Wheat fields in England http://commons.wikimedia.org/wiki/File%3AWheat_field_at_Cheseridge_Farm_-_geograph.org.uk_-_20777.jpg http://upload.wikimedia.org/wikipedia/commons/4/4e/Wheat_field_at_Cheseridge_Farm_-_geograph.org.uk_-_20777.jpg Pam Brophy [CC-BY-SA-2.0 (www.creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons Marketplace in Senegal, Africa http://commons.wikimedia.org/wiki/File%3AKolda-bradybd.jpg


http://upload.wikimedia.org/wikipedia/commons/c/c6/Kolda-bradybd.jpg By Bradybd (Own work) [CC-BY-3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons Freeway interchange interstate 60 and interstate 710 ©2013 Google Georgia Pacific lumber mill, Eureka, CA http://commons.wikimedia.org/wiki/File:GEORGIA_PACIFIC_LUMBER_MILL_-_NARA_-_545925.jpg This work is in the public domain in the United States because it is a work prepared by an officer or employee of the United States Government as part of that person’s official duties under the terms of Title 17, Chapter 1, Section 105 of the US Code. See Copyright. Udachnaya diamond mine http://commons.wikimedia.org/wiki/File%3AUdachnaya_pipe.JPG http://upload.wikimedia.org/wikipedia/commons/8/83/Udachnaya_pipe.JPG By Stepanovas (Stapanov Alexander). Timestamp at the bottom right was removed by Michiel Sikma in 2006. (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons Gemasolar power plant, Spain. http://commons.wikimedia.org/wiki/File%3AGemasolar.jpg http://upload.wikimedia.org/wikipedia/commons/a/af/Gemasolar.jpg By Torresol Energy (www.torresolenergy.com) [FAL], via Wikimedia Commons Geely automotive assembly line, China. http://commons.wikimedia.org/wiki/File%3AGeely_assembly_line_in_Beilun%2C_Ningbo.JPG http://upload.wikimedia.org/wikipedia/commons/5/55/Geely_assembly_line_in_Beilun%2C_Ningbo.JPG By Siyuwj (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons Glen Canyon Dam, northern Arizona. Tom Morris Landfill for urban solid waste in Guatemala. http://commons.wikimedia.org/wiki/File%3ABasurero_de_la_zona_3_-_Guatemala.jpg http://upload.wikimedia.org/wikipedia/commons/5/52/Basurero_de_la_zona_3_-_Guatemala.jpg By Surizar (http://www.flickr.com/photos/puchica/2719131230/

) [CC-BY-SA-2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons Maxwell Air Force Base, Alabama. http://commons.wikimedia.org/wiki/File%3AMaxwell_Air_Force_Base.jpg http://upload.wikimedia.org/wikipedia/commons/9/9c/Maxwell_Air_Force_Base.jpg By United States Department of Agriculture (USDA), Farm Services Agency [Public domain], via Wikimedia Commons Aerial image of Maxwell Air Force Base in Montgomery, Alabama, United States This image or file is a work of a United States Department of Agriculture employee, taken or made as part of that person's official duties. As a work of the U.S. federal government, the image is in the public domain. World human population through the year 2000. http://commons.wikimedia.org/wiki/File%3APopulation_curve.svg http://upload.wikimedia.org/wikipedia/commons/b/b7/Population_curve.svg By El T [Public domain], via Wikimedia Commons Garden greenhouse. http://commons.wikimedia.org/wiki/File%3AGartengew%C3%A4chshaus.JPG http://upload.wikimedia.org/wikipedia/commons/c/c6/Gartengew%C3%A4chshaus.JPG By Jürgi-würgi (Own work) [Public domain], via Wikimedia Commons Diagram of the greenhouse effect. Tom Morris Weather station instruments. http://commons.wikimedia.org/wiki/File:Weather_Station_USDA.jpg USDA photo by Scott Bauer. Image Number K7688-7. From: http://www.ars.usda.gov/is/graphics/photos/k7688-7.htm This image is in the public domain because it contains materials that originally came from the Agricultural Research Service, the research agency of the United States Department of Agriculture. Global land-ocean temperature index. GISS Surface Temperature Analysis Analysis Graphs and Plots https://data.giss.nasa.gov/gistemp/graphs_v3/ https://data.giss.nasa.gov/gistemp/graphs_v3/Fig.A2.pdf Source: NASA Goddard Institute for Space Studies Recent warming anomaly as of 2017


Temperature anomaly 2017 GISS Surface Temperature Analysis Global Maps from GHCN v3 Data https://data.giss.nasa.gov/gistemp/maps/ https://data.giss.nasa.gov/tmp/gistemp/NMAPS/tmp_GHCN_GISS_ERSSTv5_1200km_Trnd1212_1980_2017_100__180_90_0__2_/amaps.png Source: NASA Goddard Institute for Space Studies Preparing ice core equipment in Antarctica. http://commons.wikimedia.org/wiki/File%3AIce-core_drill_hg.jpg http://upload.wikimedia.org/wikipedia/commons/1/1c/Ice-core_drill_hg.jpg By Hannes Grobe, Alfred Wegener Institute for Polar and Marine Research (Own work) [CC-BY-SA-2.5 (http://creativecommons.org/licenses/by-sa/2.5)], via Wikimedia Commons Vostok ice core data. http://commons.wikimedia.org/wiki/File%3AVostok_Petit_data.svg http://upload.wikimedia.org/wikipedia/commons/b/b8/Vostok_Petit_data.svg By Vostok-ice-core-petit.png: NOAA derivative work: Autopilot (Vostok-ice-core-petit.png) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons Recent global CO2 and temperature trends. http://www.globalchange.gov/resources/gallery?func=viewcategory&catid=2 Source: NOAA/NCDC Human and natural influences on global temperature. From Forster, P., Ramaswamy, V., Artaxo, P., Berntsen, T., Betts, R. A., Fahey, D. W., et al. (2007). Cited in the “Works Cited” section above. Abstract model of global climate system. http://commons.wikimedia.org/wiki/File%3AAtmosphericModelSchematic.png http://upload.wikimedia.org/wikipedia/commons/7/73/AtmosphericModelSchematic.png By NOAA [Public domain or Public domain], via Wikimedia Commons Predicted global temperatures. From Meehl, G. A., Stocker, T. F., Collins, W. D., Friedlingstein, P., Gaye, A. T., Gregory, J. M., et al. (2007). Cited in the “Works Cited” section above. Trees killed by pine beetles on Mount Fraser in Alberta, Canada. http://commons.wikimedia.org/wiki/File%3AMt_Fraser_-_Pine_Beetle_Damage.JPG

http://upload.wikimedia.org/wikipedia/commons/5/5e/Mt_Fraser_-_Pine_Beetle_Damage.JPG By Themightyquill (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons Toyota Prius. Toyota Prius 2017 https://commons.wikimedia.org/wiki/File%3ATOYOTA_PRIUS_ZVW50_A_E-Four_Front.JPG https://upload.wikimedia.org/wikipedia/commons/9/91/TOYOTA_PRIUS_ZVW50_A_E-Four_Front.JPG https://upload.wikimedia.org/wikipedia/commons/thumb/9/91/TOYOTA_PRIUS_ZVW50_A_E-Four_Front.JPG/1024px-TOYOTA_PRIUS_ZVW50_A_E-Four_Front.JPG By Renaik (Own work) [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons Firefighters battle a wildfire near Fort Collins. Colorado in 2012. http://commons.wikimedia.org/wiki/File%3AFirefighters_at_High_Park_Wildfire_June_10%2C_2012.jpg http://upload.wikimedia.org/wikipedia/commons/2/21/Firefighters_at_High_Park_Wildfire_June_10%2C_2012.jpg By U.S. Department of Agriculture (Flickr: 20120620-FS-UNK- 0005) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0) or Public domain], via Wikimedia Commons Uninhabitable regions as a combination of high temperatures and high relative humidity. By Sherwood and Huber, 2010. Smog in Beijing, China. 2014. https://commons.wikimedia.org/wiki/File%3ASmog_in_Beijing_CBD.JPG https://upload.wikimedia.org/wikipedia/commons/3/3b/Smog_in_Beijing_CBD.JPG By 螺钉 (Own work) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons Trapped by a thermal inversion, thick smog accumulates in the Los Angeles basin in 1972. http://commons.wikimedia.org/wiki/File:SMOG,_SAN_GABRIEL_MOUNTAINS_-_NARA_-_542676.jpg Author Daniels, Gene, photographer, Photographer (NARA record: 8463941) Record creator Environmental Protection Agency. (12/02/1970 - ) Date 05/1972 This work is in the public domain in the United States because it is a work prepared by an officer or employee of the United States Government as part of that person’s


official duties under the terms of Title 17, Chapter 1, Section 105 of the US Code. See Copyright. Acid rain effects on a forest in central Germany. 2007. http://commons.wikimedia.org/wiki/File%3ASilberwald.jpg http://upload.wikimedia.org/wikipedia/commons/d/d4/Silberwald.jpg I, ArtMechanic [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons Limestone sculpture damaged by acid rain. Europe. http://commons.wikimedia.org/wiki/File%3APollution_-_Damaged_by_acid_rain.jpg http://upload.wikimedia.org/wikipedia/commons/5/5b/Pollution_-_Damaged_by_acid_rain.jpg By Nino Barbieri (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC-BY-2.5 (http://creativecommons.org/licenses/by/2.5)], via Wikimedia Commons pH scale http://commons.wikimedia.org/wiki/File%3A216_pH_Scale-01.jpg http://upload.wikimedia.org/wikipedia/commons/2/23/216_pH_Scale-01.jpg By OpenStax College [CC-BY-3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons Stratospheric ozone depletion over Antarctica. 2017. https://ozonewatch.gsfc.nasa.gov/monthly/monthly_2017-09_SH.html https://ozonewatch.gsfc.nasa.gov/ozone_maps/images/climate/OZONE_D2017-09_G%5E716X716_PA:TIME.IOMPS_PNPP_V21_MGEOS5FP_LSH.PNG Source: NASA, Goddard Space Flight Center Freon. Widely used CFC. Tom Morris Chemical diagram showing how CFCs destroy ozone. Tom Morris Skin cancer. http://commons.wikimedia.org/wiki/File%3AMelanoma_(2).jpg http://upload.wikimedia.org/wikipedia/commons/c/ca/Melanoma_%282%29.jpg By Unknown photographer [Public domain], via Wikimedia Commons

In medieval times, dumping chamber pots onto the street was normal practice http://commons.wikimedia.org/wiki/File%3ALatrint%C3%B6mning_medeltid.jpg http://upload.wikimedia.org/wikipedia/commons/9/99/Latrint%C3%B6mning_medeltid.jpg See page for author [Public domain], via Wikimedia Commons Eutrophic pond. Tom Morris Cuyahoga River catches fire near Cleveland, Ohio in 1952. Image Title: Cuyahoga River Fire Nov. 3, 1952 Source: Special Collections, Cleveland State University Library Collection: Cuyahoga River, Fires, Accidents Artist: James Thomas (United Press International) Activated sludge sewage treatment. LACSD Tom Morris Trickling filter sewage treatment. OCSD Tom Morris Silt from eroded surroundings accumulates at the mouth of the Betsiboka River, Madagascar (June 2011). http://commons.wikimedia.org/wiki/File%3AEstuaries%2C_Northwest_Coast_of_Madagascar.JPG http://upload.wikimedia.org/wikipedia/commons/e/ea/Estuaries%2C_Northwest_Coast_of_Madagascar.JPG By ISS Astronaut photograph (NASA Earth Observatory) [Public domain], via Wikimedia Commons Dust storm approaches Stratford, Texas in 1935. http://commons.wikimedia.org/wiki/File%3ADust_Storm_Texas_1935.jpg http://upload.wikimedia.org/wikipedia/commons/d/d9/Dust_Storm_Texas_1935.jpg By NOAA George E. Marsh Album, theb1365, Historic C&GS Collection [Public domain], via Wikimedia Commons Drums of hazardous chemical wastes leak into a swampy site in Texas (1973). http://commons.wikimedia.org/wiki/File:ABOUT_3,000_DRUMS_CONTAINING_HAZARDOUS_INDUSTRIAL_WASTES_HAVE_BEEN_STORED_FOR_SIX_MONTHS_IN_THIS_SWAMPY_FIELD_NEAR..._-_NARA_-_552883.jpg Author Messina, John, 1940-, Photographer (NARA record: 8464458) Date 06/1973 This work is in the public domain in the United States because it is a work prepared by an officer or employee of the United States Government as part of that person’s official duties under the terms of Title 17, Chapter 1, Section 105 of the US Code. See Copyright.


Love Canal Protest https://upload.wikimedia.org/wikipedia/commons/6/6d/Love_Canal_protest.jpg This image (or other media) is a work of an Environmental Protection Agency employee, taken or made as part of that person's official duties. As works of the U.S. federal government, all EPA images are in the public domain. Lois Gibbs (2010) http://commons.wikimedia.org/wiki/File%3ALois_Gibbs_at_NMU_in_Marquette%2C_MI_10-15-10_(2).jpg http://upload.wikimedia.org/wikipedia/commons/b/bc/Lois_Gibbs_at_NMU_in_Marquette%2C_MI_10-15-10_%282%29.jpg By Yoopernewsman (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons Salt buildup in Utah farmland irrigated with Colorado River water. http://commons.wikimedia.org/wiki/File%3ANRCSUT03050_-_Utah_(6469)(NRCS_Photo_Gallery).jpg http://upload.wikimedia.org/wikipedia/commons/6/69/NRCSUT03050_-_Utah_%286469%29%28NRCS_Photo_Gallery%29.jpg By Photo by Ron Nichols, USDA Natural Resources Conservation Service. (USDA NRCS Photo Gallery: NRCSUT03050.tif) [Public domain], via Wikimedia Commons Atomic bomb test in Nevada, 1951. http://commons.wikimedia.org/wiki/File%3ABuster-Jangle_Easy_002.jpg http://upload.wikimedia.org/wikipedia/commons/4/46/Buster-Jangle_Easy_002.jpg By Federal government of the United States [Public domain], via Wikimedia Commons Chernobyl nuclear power plant in 2009 http://commons.wikimedia.org/wiki/File%3ACernobylmb.jpg http://upload.wikimedia.org/wikipedia/commons/d/d5/Cernobylmb.jpg By Wanrouter (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons Pripyat, Ukraine with Chernobyl in background http://commons.wikimedia.org/wiki/File%3AView_of_Chernobyl_taken_from_Pripyat.JPG http://upload.wikimedia.org/wikipedia/commons/6/6e/View_of_Chernobyl_taken_from_Pripyat.JPG By Jason Minshull (This photo is the author's own work) [Public domain], via Wikimedia Commons

Fukushima nuclear power plant during 2011 disaster. http://commons.wikimedia.org/wiki/File%3AFukushima_I_reactor_units_3_and_4_by_Digital_Globe.jpg http://upload.wikimedia.org/wikipedia/commons/6/6e/Fukushima_I_reactor_units_3_and_4_by_Digital_Globe.jpg By Digital Globe [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons World map with labels http://commons.wikimedia.org/wiki/File%3ABlankMap-World6.svghttp://upload.wikimedia.org/wikipedia/commons/0/03/BlankMap-World6.svg By Canuckguy (talk) and many others (see File history) [Public domain], via Wikimedia Commons Soil erosion following deforestation, Madagascar. Imagery copyright 2013 DigitalGlobe, CnesSpot Image, Map data copyright 2013 Google Ring-tailed lemur. http://commons.wikimedia.org/wiki/File%3ALemur_Catta02.jpg http://upload.wikimedia.org/wikipedia/commons/5/5f/Lemur_Catta02.jpg By Bernard Gagnon (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0-2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons Baobab trees, Madagascar http://commons.wikimedia.org/wiki/File%3ABaobabs.jpg http://upload.wikimedia.org/wikipedia/commons/4/4d/Baobabs.jpg By ino paap (http://www.flickr.com/photos/inopaap/27178285/) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons Oil palm plantations following deforestation, Borneo. Imagery copyright 2013 DigitalGlobe, TerraMetrics. Map data copyright 2013 Tele Atlas Orangutan. http://commons.wikimedia.org/wiki/File%3AOrang-utan_bukit_lawang_2006.jpg http://upload.wikimedia.org/wikipedia/commons/9/93/Orang-utan_bukit_lawang_2006.jpg By Tbachner [Public domain], via Wikimedia Commons


Terraced slopes reduce erosion following deforestation, Kenya. Imagery copyright 2013 DigitalGlobe, Cnes/Spot Image. Map data copyright Google African wild dog http://commons.wikimedia.org/wiki/File%3ALycaon_pictus_(portrait).jpg http://upload.wikimedia.org/wikipedia/commons/a/a9/Lycaon_pictus_%28portrait%29.jpg By Hans Hillewaert (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons Cheetah. http://commons.wikimedia.org/wiki/File%3ACheetah4.jpg http://upload.wikimedia.org/wikipedia/commons/a/a9/Cheetah4.jpg By schani (http://flickr.com/photos/schani/32966097/) [CC-BY-SA-2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons Cattle ranches with telltale corals and water holes, Rondonia, Brazil. Imagery copyright 2013 DigitalGlobe, Cnes/Spot Image, U.S. Geological Survey. Map data copyright 2013 MapLink Massive deforestation of Rondonia, Brazil. http://commons.wikimedia.org/wiki/File%3AFires_and_Deforestation_on_the_Amazon_Frontier%2C_Rondonia%2C_Brazil_-_August_12%2C_2007.jpg http://upload.wikimedia.org/wikipedia/commons/b/b6/Fires_and_Deforestation_on_the_Amazon_Frontier%2C_Rondonia%2C_Brazil_-_August_12%2C_2007.jpg By Jesse Allen and Robert Simmon (NASA Earth Observatory) [Public domain], via Wikimedia Commons Jaguar http://commons.wikimedia.org/wiki/File%3AStanding_jaguar.jpg http://upload.wikimedia.org/wikipedia/commons/0/0a/Standing_jaguar.jpg By USFWS [Public domain], via Wikimedia Commons Wood Canyon in southern Orange County, CA. Imagery copyright 2013 DigitalGlobe, U.S. Geological Survey, USDA Farm Service Agency, Data CSUMB SFML, CA OPC. Map data copyright Google. California Gnatcatcher. http://commons.wikimedia.org/wiki/File%3ACalifornia_Gnatcatcher.jpg http://upload.wikimedia.org/wikipedia/commons/6/6f/California_Gnatcatcher.jpg

By Peterson, B. Moose [Public domain], via Wikimedia Commons Fragmented habitat Tom Morris California condor. http://commons.wikimedia.org/wiki/File%3AGymnogyps_californianus_-Bitter_Creek_National_Wildlife_Refuge%2C_California%2C_USA_-flying-8.jpg http://upload.wikimedia.org/wikipedia/commons/1/17/Gymnogyps_californianus_-Bitter_Creek_National_Wildlife_Refuge%2C_California%2C_USA_-flying-8.jpg By Pacific Southwest Region U.S. Fish and Wildlife Service from Sacramento, US (Flying California condor Uploaded by Snowmanradio) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons Arabian Oryx. http://commons.wikimedia.org/wiki/File%3AArabian_orix_.JPG http://upload.wikimedia.org/wikipedia/commons/b/bf/Arabian_orix_.JPG By Tamar Assaf (Own work) [Public domain], via Wikimedia Commons Clapper rail. http://commons.wikimedia.org/wiki/File%3ARallus_longirostris_2.jpg http://upload.wikimedia.org/wikipedia/commons/a/ae/Rallus_longirostris_2.jpg By Riverbanks Outdoor Store from New Port Richey, FL, United States (Clapper Rail 2 Uploaded by berichard) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons Wildebeest and zebra on the Masaai Mara, Kenya. http://commons.wikimedia.org/wiki/File%3AWildebeests_in_the_Masaai_Mara.jpg http://upload.wikimedia.org/wikipedia/commons/5/58/Wildebeests_in_the_Masaai_Mara.jpg By DEMOSH from Nairobi, Kenya (_MG_5157) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons Fish ladder on the John Day Dam, Columbia River, USA. http://commons.wikimedia.org/wiki/File:John_Day_Dam_fish_ladder.jpg This image or file is a work of a U.S. Army Corps of Engineers soldier or employee, taken or made as part of that person's official duties. As a work of the U.S. federal government, the image is in the public domain.


Cattlemen capture a gray wolf in Wyoming, USA http://commons.wikimedia.org/wiki/File%3AGrabill_-_Roping_gray_wolf.jpg http://upload.wikimedia.org/wikipedia/commons/7/78/Grabill_-_Roping_gray_wolf.jpg John C. H. Grabill [Public domain], via Wikimedia Commons Male black rhinoceros with calf. http://commons.wikimedia.org/wiki/File%3ABlack_rhino_with_calf_(male).jpeg http://upload.wikimedia.org/wikipedia/commons/e/ed/Black_rhino_with_calf_%28male%29.jpeg By Stromayer, Karl [Public domain], via Wikimedia Commons Foxglove flower http://commons.wikimedia.org/wiki/File%3AFoxglove_wild_flower.jpg http://upload.wikimedia.org/wikipedia/commons/a/af/Foxglove_wild_flower.jpg By Danesman1 (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons Deadly Nightshade http://commons.wikimedia.org/wiki/File%3AFlickr_-_don_macauley_-_Deadly_Nightshade.jpg http://upload.wikimedia.org/wikipedia/commons/d/d6/Flickr_-_don_macauley_-_Deadly_Nightshade.jpg By Donald Macauley (Flickr: Deadly Nightshade) [CC-BY-SA-2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons Biodiversity hotspots. http://commons.wikimedia.org/wiki/File%3ABiodvhot.png http://upload.wikimedia.org/wikipedia/commons/9/9c/Biodvhot.png By T. Hengl (http://www.biodiversityhotspots.org) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons Full disk image of Earth. http://commons.wikimedia.org/wiki/File%3ABlue_Marble.jpg http://upload.wikimedia.org/wikipedia/commons/1/1a/Blue_Marble.jpg By NASA/NOAA/GSFC/Suomi NPP/VIIRS/Norman Kuring [Public domain], via Wikimedia Commons

One species über alles - MorrisCourse.com€¦ · power lines crisscross the land. Dams impede...

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