Our understanding of the Earth's ozone will be greatly enhanced by this research. The Earth's ozone layer protects life below from the harmful ultraviolet radiation from the Sun that can damage DNA molecules, leading to formation of skin cancers. Very low levels of ozone over the Arctic found during the 1990s, raised concerns that an Arctic ozone hole might be forming. Recent computer modeling suggests that greenhouse gas warming might lead to larger than expected Arctic ozone losses and may delay the expected recovery of the ozone layer globally. In 1985, scientists found an ozone hole over the South Pole that reappears each year during the Southern Hemisphere winter and spring.
Ozone depletion is caused by human-made chlorine and bromine compounds, scientists agree.
The chlorine compounds have been used as refrigerants, aerosol sprays, solvents and foam blowing agents, while bromine containing halons were used in fire extinguishing. Production of chlorofluorocarbons ceased in 1996 in developed countries under the Montreal Protocol and its Amendments. Reserves of dry natural gas also declined by two percent, according to data released Wednesday by the Energy Information Administration. This, in turn, is related to the decline in the price for crude oil that hit new lows by December 1998. Price levels by late last year were the lowest since 1935 after adjusting for inflation, and were responsible for a drop of almost 60 percent in the number of rigs drilling for oil.