7/18/2019 Global Warming

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Global warming is the warming near the earth's surface that results when the

earth's atmosphere traps the sun's heat. The earth is getting warmer. The

changes are small, so far, but they are expected to grow and speed up. Within

the next fty to one hundred years, the earth may be hotter than it has been in

the past million years. As oceans warm and glaciers melt, land and cities along

coasts may be ooded. eat and drought may cause forests to die and foodcrops to fail. Global warming will a!ect weather e"erywhere, plants and animals

e"erywhere, people e"erywhere# humans are warming the earth's atmosphere

by burning fuels, cutting down forest, and by ta$ing part in other acti"ities that

release certain heat trapping gases into the air.

%ne ma&or cause of global warming is the use of fossil fuels. ossil fuels li$e coal,

oil, and natural gas that were formed from the remains of plant material

deposited during the earth's carboniferous period. We ha"e $nown for only a few

thousand years that coal, oil, and natural gas can be burned to pro"ide energy. (t

was not until the mid)*+s, howe"er, that we began to burn "ery large-uantities of these fossil fuels. The worldwide consumption of fossil fuel has

increased dramatically. The world now burns at least "e billion tons of fossil fuel

each year. As this carbon dioxide from burning fossil fuels enters the

atmosphere, some of it is ta$en up by photosynthesiing plants, and the oceans

absorb some. /ut because we are burning so much fossil fuel at such a rapid

rate, we are putting carbon dioxide into the atmosphere much faster than these

natural processes are ta$ing it out. There is no longer a balance between the

amount of carbon dioxide being added to the air and the amount of carbon

dioxide being remo"ed. As a result, the concentration of carbon dioxide in the

air is steadily increasing.