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FREQUENTLY ASKED QUESTIONS
<br /> If a gallon of gasoline weighs only S pounds, how can it pro- How long do greenhouse Average CO2 emissions per year
<br /> duce about 20 pounds of carbon dioxide when it combusts ? gases stay in the atmos - SUV . . . . . . . . . . . . . . . . 15 m 10 tons
<br /> Gasoline consists mostly of carbon , plus a small amount of hydro- phere and trap heat ? Compact . . . . . . . . 27 . 5 mpg . . . 5 . 5 tons
<br /> gen and a few impurities . When gasoline combusts, each carbon The amount of time GHG Fuel efficient . . . 40 mpg . . . . . 3 . 5 tons
<br /> atom combines with two atoms of heavier oxygen atoms, produc- stays in the atmosphere Bicycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 tons
<br /> ing about 20 pounds of carbon dioxide . varies depending on the type of gas . Methane, for example, lasts
<br /> about twelve years , while carbon dioxide lasts for over a century.
<br /> How can carbon dioxide that weighs tons float in the atmos -
<br /> phere and disappear? Are extreme weather events due to global warming ?
<br /> All substances, including gases, have weight . The molecules of car- As the world warms, some extreme climate events, like the frequency
<br /> bon dioxide are relatively light, and as a gas, have lots of space be. of heat waves and very heavy precipitation, are expected to increase ,
<br /> tween them and disperse easily throughout the atmosphere . AI - It is not possible to link any particular weather or climate event de-
<br /> though carbon dioxide gas seems invisible and weightless, it is real finitively to global warming .
<br /> matter that comprises a huge portion of modern society's waste . Be-
<br /> cause we can 't see, feel, smell, or taste carbon dioxide gas, we have What is the difference between the greenhouse effect and the
<br /> difficulty realizing that it's even there, let alone a serious problem . hole in the ozone layer?
<br /> The greenhouse effect is a warming of the Earth by the gases in the at-
<br /> Why are greenhouse gases measured In equivalent tons mosphere that surround the Earth and hold in heat like a blanket .
<br /> of CO27. Greenhouse gas makes our Earth habitable, but too much greenhouse
<br /> Greenhouse gases have different strengths or effects in their ability gas, like too many blankets, can make the Earth unbearable . The hole
<br /> to trap heat . Converting emissions to the equivalent amount of car- in the ozone layer, also known as global depletion of stratospheric
<br /> bon dioxide allows for comparisons between greenhouse gases of ozone, is caused by a type of greenhouse gas called chlorofluorocar-
<br /> varying strengths . For instance, methane is twenty-one times more bons (CFCs ), used in refrigeration, air conditioning, and as solvents .
<br /> powerful than carbon dioxide in its capacity to trap heat, Therefore CFCs are being phased out under the Montreal Protocol, an interna -
<br /> 1 ton of methane is considered equal to 21 tons of carbon dioxide . tional agreement. Because of the success of the Montreal Protocol,
<br /> many scientists predict that the hole in the ozone layer will shrink .
<br /> What are the primary greenhouse gases humans emit ? The Montreal Protocol is a good example of what countries can do
<br /> They are carbon dioxide, methane, nitrous oxide, chlorofluorocar- when they work together for mutual benefit. The same can be done
<br /> bons , perfluorocarbons, and sulphur hexafluoride . Carbon dioxide for global climate change .
<br /> is the most prevalent and has the most cumulative impact of these
<br /> gases . It represents over 80 percent of GHG emissions in the U . S . What is the Kyoto Protocol ?
<br /> What human activities contribute to climate change ?
<br /> In 1997, at Kyoto, Japan , representatives of leading industrialized
<br /> countries responsible for over 90 per cent of global warming, agreed
<br /> The combustion of coal, oil, to reduce their GHG emissions by five per cent from 1990 levels . The
<br /> and natural gas, as well as Sources of U . S . GHG emissions
<br /> U . S . , responsible for one-quarter of the worlds total greenhouse gas
<br /> deforestation and various Electricity generation . . . . . 37 %
<br /> • Vehicles . o emissions, initially accepted but later rejected the agreement. Many
<br /> agricultural and industrial . 31 /o
<br /> o experts believe that without U . S . parti
<br /> /o
<br /> practices , are altering the Industry . . . . . 21 cipation , the Kyoto Protocol
<br /> . . . . . . . . . .
<br /> Other 9 a 0 a 5 0 . . . . . . 6 $ 11 % cannot accomplish its objectives ,
<br /> composition of the atmos -
<br /> phere and changing the climate . If the U . S . were to sign the Kyoto Protocol, by how much would
<br /> we need to reduce our GHG emissions?
<br /> How much of the carbon dioxide being added to the atmos. Under terms of the Kyoto Protocol, the U . S . would reduce its emis -
<br /> phere is from the use of fossil fuel ? sions by 7 percent below 1990 levels by the year 2012 . This would be
<br /> About 80 to 85 % of the CO2 being added to the atmosphere comes quite a challenge because, according to the U . S . Environmental Pro .
<br /> from current fossil fuel use . tection Agency, this country's emissions increased by 14 . 2 percent
<br /> from 1990 to 2000 . continued on page 18
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