The results of the effects can alter both the sources and sinks of greenhouse gases and chemically important gases such as ozone. The changes contribute to biosphere-atmosphere feedback that attenuates or reinforces the accumulation of these gases in the atmosphere. Increases in solar UV radiation could influence terrestrial and aquatic biogeochemical cycles, thereby altering both sources and sinks of chemically important greenhouse gases and trace gases, e.g. carbon dioxide (CO2), carbon monoxide (CO), carbonyl sulfide (COS), and possibly other gases, including ozone. These potential changes would contribute to biosphere-atmosphere feedbacks that attenuate or reinforce the atmospheric accumulation of these gases. Likely effects include increased smog in urban centers and acid rain in rural areas. The effects of ozone depletion on global biogeochemical cycles, through increased UV-B radiation at the Earth's surface, have continued to be documented over the past 4 years. In this report we also document various effects of UV-B interacting with global climate change because the detailed interactions between ozone depletion and climate change are critical to predicting and assessing Earth's future environmental impact.