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Global Warming
Many climatologists believe that increasing atmospheric concentrations
of carbon dioxide and other “greenhouse gasses” released by human
activities, such as burning fossil fuels and deforestation, are warming
the Earth. The mechanism commonly known as the “greenhouse effect” is what
makes the Earth habitable. These gasses in the atmosphere act like the
glass of a greenhouse, letting sunlight in and preventing heat from
escaping.
Climatic modeling studies generally estimate that global temperatures
will rise a few degrees Celsius in the next century. Such a warming is
likely to raise sea levels by expanding ocean water and melting glaciers
and the polar ice cap. A 2007 E.P.A. report confirmed that the global mean
sea level rose up to three milometers per year due to global warming. In
1995, the American Medical Association warned that changes in global
temperatures could introduce new infectious diseases.
No one knows for certain what the consequences of this predicted
climate change will be on the quality of human life, ecosystems, and loss
of arable land. Some scientists disagree with the conclusions drawn from
global climate models because the effects of clouds have not been factored
into the current models.
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