Fossil
fuels are composed mostly of carbon. When they are burned this carbon is
released into the atmosphere, mainly in the form of carbon dioxide, CO2
.We
currently emit roughly 5 billion tones of carbon into the atmosphere each year.
As a result, there has been a steady increase in global atmospheric levels of
CO2. This increase in CO2 (along with other gases including methane, ozone, and
CFCs) presents a problem, because these gases are ¡§greenhouse¡¨
gases, that are they absorb infrared radiation (i.e., "heat") that is
radiated out from the earth. Thus, heat that would otherwise be lost to space is
trapped in the atmosphere, leading to increased temperatures. Criminologists
have predicted that, as a result of increasing concentrations of greenhouse
gases in the atmosphere, the earth's temperature will increase by about 30
C by the year
2030.
As the
earth gets warmer, there's a serious risk the climate will change in ways that
will seriously disrupt our lives. Among the severest impacts: a rise in sea
level; more heat waves and droughts; more extreme weather events, producing
floods and property destruction; and tropical diseases spreading to areas where
they've never been known before. If we don't take action, global warming will
threaten our health, our cities, our farms, and our forests, wetlands, and other
natural habitats.
