Learn about
Global
warming
How Temperature Rise Occurs The greenhouse effect Deforestation The IPCC
Evidence of Global Warming Changes on the planet Earth The Larsen B ice shelf Results of global warming
Impact on Living Things Polar bears Coral reefs The ecosystem
Global Warming and Its Effect on Our Lives Danger of extinction Global warming and human beings
Help Prevent Global Warming
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What can we do to reduce global warming? Start at home
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Quizzes Projects Answers Glossary
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14/12/2007 04:20:46 PM
how Temperature rise occurs Global warming refers to an
increase in the planet’s average surface temperature. Natural and human causes have been suggested to explain this phenomenon. The rise in temperature of the past 50 years is most likely due to an enhanced greenhouse effect, caused by an increase in greenhouse gas concentrations in the atmosphere.
The Greenhouse effecT The Earth’s atmosphere traps part of the sun’s energy, keeping it at an average temperature of 13 oC (55.4 oF). Meanwhile the Earth’s surface and the clouds reflect the other part of this solar radiation in the form of heat. This natural phenomenon causes what we call the greenhouse effect and without it, there would be no life on Earth and in the oceans, at least not life with the current diversity and degree of complexity. 2
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Solar radiation passes through the atmosphere.
The Earth's surface absorbs most of the solar radiation, and the Earth warms up.
The other part is reected back into the atmosphere.
The increase in the emission of greenhouse effect gases forces these gases to get stuck in the atmosphere, forming a layer that gets thicker and thicker. It retains the heat of the sun, causing our planet to get warmer.
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14/12/2007 01:40:03 PM
how Temperature rise occurs Global warming refers to an
increase in the planet’s average surface temperature. Natural and human causes have been suggested to explain this phenomenon. The rise in temperature of the past 50 years is most likely due to an enhanced greenhouse effect, caused by an increase in greenhouse gas concentrations in the atmosphere.
The Greenhouse effecT The Earth’s atmosphere traps part of the sun’s energy, keeping it at an average temperature of 13 oC (55.4 oF). Meanwhile the Earth’s surface and the clouds reflect the other part of this solar radiation in the form of heat. This natural phenomenon causes what we call the greenhouse effect and without it, there would be no life on Earth and in the oceans, at least not life with the current diversity and degree of complexity. 2
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THE MAIN GREENHOUSE GASES THAT CONTRIBUTE TO AN INCREASE IN THE AVERAGE GLOBAL TEMPERATURE ARE METHANE, NITROUS OXIDE, CARBON DIOXIDE AND CHLOROFLUOROCARBONS. WHERE DO THEY COME FROM? METHANE Landfills Decomposition of organic matter Combustion of natural gas, coal, and petroleum Cattle farms Rice plantations Wetlands NITROUS OXIDE Combustion of fossil fuel and plant matter Use of fertilizers Industrial processes CARBON DIOXIDE Respiration of living things Decomposition of plants and animals Forest fires Energy sources used by humans (wood, coal, petroleum, and natural gas) Deforestation Cement production CHLOROFLUOROCARBONS Refrigeration systems and aerosol sprays
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It is important to remember that the greenhouse effect is a natural phenomenon on Earth. It becomes an environmental issue when the emission of greenhouse gases such as carbon dioxide, methane, chlorofluorocarbons, and nitrous oxide begins to rise because of human influence. The increase in the concentration of these gases causes the average global temperature to rise and this is known as global warming. The increase in CO2 is considered the main factor in global warming because it represents 60 percent of the gross volume of greenhouse gas emissions. CO2 remains active in the atmosphere for approximately 100 years and retains the solar radiation reflected by the planet’s surface, thus 2 making Earth warmer. 002a003_AG_ingl.indd 6
14/12/2007 01:40:13 PM
Deforesta t ...is another contributing factor to the greenhouse effect because trees absorb carbon dioxide from the atmosphere. This natural process – CO2 absorption by the greenhouse effect gases (CO2, methane, nitrous oxide, CFCs) in the atmosphere
deforestation
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14/12/2007 01:42:42 PM
a tion... trees (and other living things) – is known as photosynthesis. During photosynthesis, carbon dioxide is absorbed from the atmosphere and oxygen (O2) is given off. a rise in the average global temperature
global warming
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pAgES 2 TO 6 1 What is the natural phenomenon that maintains the Earth at an average temperature of 13 oC (55.4 oF)? ( ) greenhouse effect ( ) global warming 2 What is one of the main greenhouse gases? ( ) oxygen ( ) carbon dioxide 3 Which gas is given off during fossil fuel combustion? ( ) carbon dioxide ( ) nitrous oxide 4 Which gas is naturally produced during the decomposition of organic matter? ( ) carbon dioxide ( ) methane 5 Which gas causes the depletion of the ozone layer? ( ) CO2 ( ) CFCs 6 What does the increase in the planet’s average surface temperature cause? ( ) global warming ( ) greenhouse effect 7 Which gas is absorbed from the atmosphere during photosynthesis? ( ) carbon dioxide ( ) oxygen 8 What are some major pollutants? ( ) the combustion of fossil fuels and forest fires ( ) reforestation and photosynthesis 9 Which nation is the planet’s major polluter? ( ) Russia ( ) the United States of America 10 Which protocol tries to reduce the consumption and production of substances that deplete the ozone layer? ( ) Montreal Protocol ( ) Kyoto Protocol 11 Which protocol requires developed nations to reduce emissions of six types of greenhouse gases by 5.2 percent below 1990 levels by 2012? ( ) Montreal Protocol ( ) Kyoto Protocol 12 Which major polluter withdrew from the Kyoto Protocol in 2001? ( ) Russia ( ) the United States of America
pAgES 8 TO 12 1 Which year was the warmest in the last thirty years? a. 2003 b. 2004 c. 2005 2 What short-term phenomenon does the melting of valley glaciers cause? a. hurricanes b. floods c. precipitation 3 A warmer world climate means more melting ice and an increase in... a. precipitation level b. river levels c. sea levels 4 What holds 9 percent of the planet’s freshwater reserves? a. valley glaciers b. rivers c. lakes 5 Where is the Larsen B platform located? a. the Himalayas b. the Antarctica Peninsula c. the Alps 6 How much of the Larsen B platform collapsed in 2002? a. less than 100 km2 b. between 100 km2 and 500 km2 c. more than 2,000 km2 7 What did this collapse cause? a. icebergs b. precipitation c. hurricanes 8 Which event may be linked to the rise in the average temperature of the sea over the last thirty years? a. droughts b. hurricanes c. floods 9 Which hurricane destroyed much of the city of New Orleans? a. Katrina b. Rita c. Dennis
ASSIGNMENT
Research climate chang e and its impact on the region where you live. Pay att ention to population gro wth, green area availability, a rise in temperature, and the increase in the number of vehicles and industries.
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