Reducing Ozone Destruction
Onesuccessstoryinreducingpollutantsthatharmtheatmosphereconcernsozone-destroying
chemicals. In 1973, scientists calculated that CFCs could reach the stratosphere and break
apart. This would release chlorine atoms, which would then destroy ozone. Based only on
their calculations, the United States and most Scandinavian countries banned CFCs in spray
cans in 1978.
More confirmation that CFCs break down ozone was needed before more was done to reduce
production of ozone-destroying chemicals. In 1985, members of the British Antarctic Survey
reported that a 50% reduction in the ozone layer had been found over Antarctica in the
previous three springs. Two years later, the ’Montreal Protocol on Substances that Deplete
the Ozone Layer’ was ratified by nations all over the world.
TheMontrealProtocolcontrolstheproductionandconsumptionof96chemicalsthatdamage
the ozone layer. Hazardous substances are phased out first by developed nations and one
decade later by developing nations. More hazardous substances are phased out more quickly.
CFCs have been mostly phased out since 1995, although some will be used in developing
nations until 2010. The Protocol also requires that wealthier nations donate money to
develop technologies that will replace these chemicals.
If CFCs were not being phased out, by 2050 they would have been probably been 10 times
more abundant than they were in 1980. The result would have been about 20 million
more cases of skin cancer in the United States and 130 million cases globally. Even though
governments have acted to reduce CFC’s, they take many years to reach the stratosphere and
they can survive there a long time before they break down. So the ozone hole will probably
continue to grow for some time before it begins to shrink. The ozone layer will reach the
same levels it had before 1980 in around 2068 and 1950 levels in one or two centuries.
Reducing Greenhouse Gases
Reducing greenhouse gas emissions is related to air pollution control. Unlike many other
air pollutants, climate change is a global problem. Climate scientists agree that all nations
must come together to reduce greenhouse gas emissions. So far, this has not occurred.
The first attempt to cap greenhouse gas emissions was the Kyoto Protocol. The Kyoto
Protocol limits greenhouse gas emissions for developed nations to below 1990 levels. Kyoto
has not achieved the success of the Montreal Protocol for several reasons. The largest
emitter of greenhouse gases, the United States, did not sign and was not bound by the
agreement. Developing nations, most notably China, signed the treaty but are not obligated
to make changes in their greenhouse gas emissions. Of the nations that agreed to reduce
their emissions, few are on track to achieve their target. More importantly, several years
have passed since this process was begun and climate scientists agree that the Protocol does
not reduce emissions nearly enough. Some say that reductions 40 times those required by