ENVIRONMENTAL SCIENCE CH.1 “our changing environment”
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Transcript of ENVIRONMENTAL SCIENCE CH.1 “our changing environment”
ENVIRONMENTAL SCIENCECH.1
“our changing environment”
THE BIG PICTURE
Human population Earth’s natural resources pollution in air, water, or soil and harms humans or other living organisms.
How can humans impact the environment less?
Env. Sci. is the study of the relationship between humans and the environment (both biotic and abiotic factors)
It is interdisciplinary - science (ecology, chemistry, agriculture) and social sciences (geography, populations, politics, economics, ethics)
Are there solutions to all environmental problems? All solutions have consequences for
someone/something/organism
TYPES OF ENVIRONMENTAL ISSUES
List any 5 environmental issues that you can think of and identify if you think it is a global, regional, or local issue.
ENVIRONMENTAL SOLUTIONS
No perfect – there’s a cost (may/maybe not financial) for everything
All about BALANCE and TRADE-OFFS: cost v. benefit
Examples – setting aside park reserves for animals by uprooting people, switching to wind/solar energy hurts the economic gain of oil companies, eggs of free-range chickens cost more money
THE ENVIRONMENT (EARTH) Life has existed on earth for 3.8 billion years Earth well suited for life
Water covers ¾ of planet Habitable temperature Moderate sunlight Atmosphere provides oxygen and carbon dioxide Soil provides essential minerals for plants
But humans are altering the planet; not always in positive ways
WHAT IS THE SIGNIFICANCE?
1999 – 6 billion 1987 – 5 billion 1975 – 4 billion 1960 – 3 billion 1930 – 2 billion 1800 – 1 billion
HUMAN IMPACTS ON ENVIRONMENT- POPULATION
Earth’s Human Population is 7 billion Growing exponentially
Increase will adversely affect living conditions in many areas of the world
POPULATION
Globally, 1 in 4 people lives in extreme poverty Cannot meet basic need for
food, clothing, shelter, health Difficult to meet population
needs without exploiting earth’s resources
GAP BETWEEN RICH AND POOR
Highly Developed Countries (HDC) Complex industrialized bases, low population
growth, high per capita incomes Ex: US, Canada, Japan
Less Developed Countries (LDC) Low level of industrialization, very high fertility
rate, high infant mortality rate, low per capita income
Ex: Bangladesh, Mali, Ethiopia
TYPES OF NATURAL RESOURCES
OVERPOPULATION
People overpopulation Too many people in a given geographic area Problem in many developing nations (like Nigeria
and India) Consumption overpopulation
Each individual in a population consumes too large a share of the resources
Problem in many highly developed nations (like US)
WHAT IS THE SIGNIFICANCE?
1999 – 6 billion 1987 – 5 billion 1975 – 4 billion 1960 – 3 billion 1930 – 2 billion 1800 – 1 billion
WORTH REVISITING…
¼ have no access to clean water/live in extreme poverty
Why does this matter? And what’s the solution? Reduces life expectancy, increased illiteracy,
insufficient access to health services, safe water and balanced nutrition.
Ecological problem - how to feed all these people without destroying ecosystems
Current birth rate – 3 per family Solution = family planning
ECOLOGICAL FOOTPRINT The average amount of land, water and ocean
required to provide that person with all the resources they consume
Earth’s Productive Land and WaterEarth’s Productive Land and Water 11.4 billion 11.4 billion hectareshectares
Amount Each Person is Allotted Amount Each Person is Allotted (divide Productive Land and Water (divide Productive Land and Water by Human Population)by Human Population)
1.9 hectares1.9 hectares
Current Global Ecological Footprint Current Global Ecological Footprint of each personof each person
2.3 hectares2.3 hectares
ECOLOGICAL FOOTPRINT COMPARISON
IPAT MODEL Measures 3 factors that affect environmental
impact (I)
I = P A TI = P A T
Environmental Environmental ImpactImpact
Number Number of peopleof people
Affluence per person Affluence per person (consumption of (consumption of
resources)resources)
Environmental effect of Environmental effect of technologies used to technologies used to
get/consume resourcesget/consume resources
ENVIRONMENTAL SUSTAINABILITY The ability to meet current human need for natural
resources without compromising the needs of future generations
Requires understanding: The effects of our actions on the earth That earth’s resources are not infinite
SUSTAINABLE DEVELOPMENT Economic development that meets the needs of the
present generation without compromising future generations
EXAMPLES OF HUMAN IMPACT ON THE ENVIRONMENT
Endocrine disrupters Ex: many chlorine containing compounds (PCBs and
dioxins), lead, mercury, DDT, phthalates Overfishing
Closed Georges Bank fishery due to low fish #s Results: lost jobs, more regulation (Magnuson-
Stevens Fishery conservation and Management Act) Declining Bird populations
Losing habitat, forest fragmentation (increases forest edge), nest parasitism (ex. Cowbirds)
Reintroducing Wolves to Yellowstone To restore ecosystem and remove wolf from
endangered species list, opposed by farmers/ranchers
Introduction of Invasive species Ex: ballast water, zebra mussels Common traits: good food supply, no predators, high
reproductive rates Stratospheric Ozone depletion
CFCs (stable!) from cooling agent Freon in refrigerators, air conditioners, aerosol propellants
Global Climate Warming/Increasing Carbon dioxide Levels CO2 from burning fossil fuels and burning forests Kyoto Protocol
Destroying Tropical Rain Forests For agriculture and pasture Ex: Amazon in Brazil Destroys habitat for organisms (ex songbirds),
erosion into local water, loss of filtration and water flow regulation, CO2