Understanding and Managing the Risks to Health and Environment from Global Atmospheric Change: A Synthesis

The global atmosphere is changing. Anthropogenic activities are increasing the concentrations of greenhouse gases and releasing synthetic compounds that deplete stratospheric ozone and increase UV-B radiation. Changes of temperature in the Northern Hemisphere during the past century strongly suggest that we are now in a period of rapid global warming relative to the past millennium. Increased concentrations of greenhouse gases are absorbing outgoing infrared radiation in the lower atmosphere, warming the troposphere and cooling the lower stratosphere. Research is beginning to indicate that losses of stratospheric ozone and increases of greenhouse gases are interdependent. Increased greenhouse gases have been implicated in the observed strengthening of stratospheric wind vortices around both poles, in turn setting the stage for further depletion of ozone and increases in UV-B radiation. Although the uncertainties are still large enough to make it difficult to assess health and ecological risks, decisions must be made. Research on indicators of risks to human health and the environment can help reduce the uncertainties in these risks and shorten the time between recognizing the risks of atmospheric change and taking concrete mitigative and adaptive actions.