Word: cfcs
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
There is only one problem. When they escape into the atmosphere, most CFCs are murder on the environment. Each CFC molecule is 20,000 times as efficient at trapping heat as is a molecule of CO2. So CFCs increase the greenhouse effect far out of proportion to their concentration...
When scientists first warned in the 1970s that CFCs could attack ozone, the U.S. responded by banning their use in spray cans. (Manufacturers switched to such environmentally benign substitutes as butane, the chemical burned in cigarette lighters.) But the rest of the world continued to use CFC-based aerosol cans, and overall CFC production kept growing. The threat became far clearer in 1985, when researchers reported a "hole" in the ozone layer over Antarctica. Although the size of the hole varies with the seasons and weather patterns, at times Antarctic ozone has been depleted by as much...
That is not good enough, however. The same stability that makes CFCs so safe in industrial use makes them extremely long-lived: some of the CFCs released today will still be in the atmosphere a century from now. Moreover, each atom of chlorine liberated from a CFC can break up as many as 100,000 molecules of ozone...
...carbon dioxide, once thought to be exclusively responsible for the greenhouse effect, is now known to cause only half the problem. The rest comes from other gases. Chlorofluorocarbons, or CFCs, are not only destroyers of the stratosphere's ozone layer but powerful greenhouse gases as well. So are nitrogen oxides, which are pollutants spewed out of automobile exhausts and power-plant smokestacks. Another greenhouse gas is methane, the primary component of natural gas. Methane is also generated by bacteria living in the guts of cattle and termites, the muck of rice paddies and the rotting garbage in landfills. Each...
...first step toward doing that is to ban the production of CFCs, which are used to make plastic foam and as coolants in refrigerators and air conditioners. These gases account for an estimated 15% of the greenhouse effect. Another strategy is to burn as much methane as possible. That adds CO2 to the air, but getting rid of the methane is well worth it. Both gases trap heat, but as a greenhouse gas, methane traps 20 times as much heat as carbon dioxide, molecule for molecule...