Preserving Earth’s Stratosphere

This article discusses that ozone levels in the Arctic and Antarctic should begin to recover due to reductions in chlorofluorocarbon production, but greenhouse warming may exacerbate losses of the gas in the polar region. It is important to understand the life cycle of ozone molecules because it plays such a vital role in screening harmful ultraviolet radiation. The concentrations of certain gases, such as these highly reactive chlorine compounds, have a critical effect on ozone levels. The chlorine found in the stratosphere comes principally from chlorofluorocarbons (CFC). A CFC release becomes well mixed throughout the troposphere in about one year. The CFCs, which enter the stratosphere from the tropical upper-troposphere region, have been measured by the Cryogenic Limb Array Etalon Spectrometer on the Upper Atmosphere Research Satellite (UARS). Recent research has suggested that greenhouse warming may lead to significant cooling of the polar region. If so, this cooling may exacerbate ozone losses despite decreasing chlorine and bromine levels.