Increases in solar UV radiation as a result of ozone depletion could affect terrestrial and aquatic biogeochemical cycles, thereby altering both sources and removal sinks of greenhouse gases, for example carbon dioxide, and possibly other trace gases including man-made pollutants. Likely effects of this may include an increase in air pollution in urban centres, and acid rain in rural areas.
Whilst increases of UV radiation may affect the production and removal of carbon dioxide, the main greenhouse gas, ozone depletion itself can influence the global climate. Ozone is also a greenhouse gas, and as well as filtering out the incoming UV radiation from the Sun, can trap much of the infrared (IR) heat trying to escape the Earth to space. If stratospheric ozone is destroyed, ozone’s contribution to the greenhouse effect is reduced. This could offset some of the global warming due to man-made emissions of carbon dioxide, methane and nitrous oxide. Ironically, as the ozone layer gradually repairs itself during the 21st century, this cooling potential will be lost. More significantly, the replacement chemicals to CFCs, the HCFCs, which themselves do little harm to the ozone layer, are very strong greenhouse gases, and are further contributing to the potential problem of global warming.