|Mount Erebus, Ross Island, Antarctica from above the clouds. |
Photo © Bruce Luyendyk
Are Global Warming and the Antarctic Ozone Hole related? Yes. Before I explain that, some basic facts.
First, the ozone hole is not really a hole but rather a seasonal decrease in ozone concentration over the Antarctic continent. Chlorine compounds that are attached to icy polar stratospheric clouds destroy ozone in the stratosphere. Ultraviolet radiation from the Sun breaks up the compounds letting loose chlorine atoms. Chlorine atoms (Cl) break ozone (O3) into ordinary oxygen (O2) and capture the freed atomic oxygen atom (O) to make ClO. The ClO attacks another ozone molecule, breaks it into two O2 molecules and a free Cl atom. Then the process starts all over again. A chain reaction is set up. Chlorine is the catalyst in the reaction. It is supplied by chlorofluorocarbons (CFCs; aerosols) that we once used in spray cans and air conditioners. Some CFCs in the troposphere eventually make their way up to the stratosphere. Nobel Prizes were awarded to those who figured this out.