Introduction

• Is the world getting warmer?

• If so, are the actions of mankind to blame for earth’s temperature increases?

• What can/should be done about these issues?

History of Earth’s Climate

• Earth formed ~4.6 billion years ago• Originally very hot• Sun’s energy output only 70% of present• Liquid water present ~4.3 billion years• Life appeared ~3.8 billion years ago• Photosynthesis began 3.5-2.5 billion years ago

– Produced oxygen and removed carbon dioxide and methane (greenhouse gases)

• Earth began cycles of glacial and interglacial periods ~3 million years ago

What Is Global Warming?

Global warming is the warming of the earth through carbon dioxide (CO2) being pumped into the atmosphere from tailpipes and smokestacks. Then the gases trap heat like the glass in a greenhouse. This is where the term the “greenhouse effect” came from.

What’s Happening?

Scientists say that the barrier insulating the continental ice caps is melting.

“The impacts of warming temperatures in Antarctica are likely to occur first in the northern sections of the continent, where summer temperatures approach the melting point of water, 32 degrees F (0 degrees C).”

What’s Happening?

As the ice melts, big chunks of glaciers will break off and become like ice cubes in a big glass of water. The ice chunks, known as icebergs, create mass in the ocean. The icebergs displace the water causing the ocean level to rise. Some of the shoreline in many places like Florida (where the land is at a low altitude) will go under water.

What Will Happen?

“Rising global temperatures are expected to raise sea level, and change precipitation and other local climate conditions. Changing regional climate could alter forests, crop yields, and water supplies. It could also affect human health, animals, and many types of ecosystems. Deserts may expand into existing rangelands, and features of some of our national parks may be permanently altered.”

What’s Happening to the Animals

• “Penguin population decline. Adelie penguin populations have shrunk by 33 percent during the past 25 years in response to declines in their winter sea ice habitat.”

Reference: Fraser, W. 1998. Antarctic biology and medicine program, University of Montana, personal communication.

Greenhouse Effect And Global Warming

Greenhouse Effect & Global Warming

• The “greenhouse effect” & global warming are not the same thing. – Global warming refers to a rise in the

temperature of the surface of the earth • An increase in the concentration of

greenhouse gases leads to an increase in the the magnitude of the greenhouse effect. (Called enhanced greenhouse effect) – This results in global warming

The “Greenhouse Effect”

The Earth’s surface thus receives energy from two sources: the sun & the atmosphere – As a result the Earth’s surface is ~33C warmer

than it would be without an atmosphere

Greenhouse gases are transparent to shortwave but absorb longwave radiation – Thus the atmosphere stores energy

We need the greenhouse effect

• The Earth’s surface temperature is ~60ºF

• Without the greenhouse effect it would be ~5ºF

• But humans are changing the radiative properties of the atmosphere and thereby the greenhouse effect

Greenhouse Gases

• Carbon dioxide – combustion of solid waste, fossil fuels (oil, natural gas, and coal), and wood and wood

products

• Methane – production and transport of coal, natural gas, and oil. Methane emissions also result

from the decomposition of organic wastes in municipal solid waste landfills, and the raising of livestock.

• Nitrous oxide – agricultural and industrial activities, as well as during combustion of solid waste and

fossil fuels.

• hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6)– industrial processes.

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Global Temperature

Temperature Of Earth

• Beginning of industrial revolution

• Increase in average global temperature by 1.4°Fahrenheit • One-degree global change is very significant• Little ice age• GISS temperature analysis• Objective of GISS scientists• Warming greater over land than ocean• Warming over Arctic, Indian and Atlantic Ocean

1. Shorter, highEnergy wavelengths Hit the earthsSurface

2. Incoming energy Is converted to heat

3. Longer, infraredWavelengths hitGreenhouse gasMolecules in theatmosphere

4. Greenhouse gasMolecules in theAtmosphere emitInfrared radiationBack towards earth

1950-59

1960-69

1970-79

1980-89

1990-99

2000-09

the

globe

has heated up by about one degree Fahrenheit over the past century.

Effects Of Global Warming

Effects

• Health• Water resources• Polar regions• Mountains• Forests• Deserts

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Effects

HEALTH

• Extreme heat

• Natural disasters

• Diseases

• Poor air quality

MOUNTAINS

• Wild life

• Farming

• Hydrology

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Effects

DESERTS POLAR REGIONS

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• Increase drought• Effect on desert plants• Desert animals

• Melting of glaciers, icecaps and ice sheets.

• Melting of permafrost• Polar bears extinction Reduced access to food Drop in body condition Increase in drowning rates Lower cub survival rates Loss of access to denning areas

Effects

WATER RESOURCES

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• Lack of fresh water Overflow of sewer system Shrinking of glaciers Sea water intrusion into ground water

• Increase in evaporation• Increase in humidity• Increase in precipitation in some

areas• rise in sea level

Deforestation Effects

• Carbon dioxide accumulation in atmosphere Released by humans Breathed out by animals Emitted by engines Respiration of plants

• Green house effect

Future Carbon Dioxide Levels

• Increasing CO2 emissions, especially in China and developing countries

• Likely to double within 150 years:– Increased coal usage– Increased natural gas usage– Decreased petroleum usage (increased cost and

decreasing supply)

The gases can stay in the atmosphere for at least 50 yearsand up to centuries.

So how can each of us slow global warming now?

Because greenhouse gas emissions are tied very closely to our energy consumption, using less fossil fuel based energy puts fewer greenhouse gases into the atmosphere.

This will help slow global warming.

Reduce our consumption of fossil fuels

Mountaintop removal for coal mining near Rawl, West Virginia.

50% of electricity in the United States is produced from coal.

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Blowing Up Your World• How many of you walked, bicycled or

took public transportation to get to school today, instead of coming by private automobile?

Our reliance on cars that burn fossil fuels is one of the major causes of increased levels of carbon dioxide in the atmosphere and it is the primary cause of urban smog.

Blowing Up Your World

• How many of you, when you drink a soft drink, throw the container into the garbage?

• Throwing away containers of any kind wastes energy and resources and adds to our waste problem. Many towns are running out of landfill space.

Blowing Up Your World

• How many of you eat take-out or cafeteria food that is served in foam or plastic containers?

• Polystyrene and other plastic containers are made from precious petrochemicals, do not decompose in landfills, and release toxic gases when they are burned in incinerators.

10 pts d

Conclusion

Global warming is affecting plants, animals, humans and the earth. We need to learn how to conserve our use of fossil fuels to minimize carbon dioxide production. This will slow down the effects of global warming.

Any question???

Feel free to question