TITLE:

"Climate change and the ozone layer: Connections and surface impacts"

ABSTRACT:

Over the last few decades, concern about the impact of ultraviolet (UV) radiation on human and ecosystem health has mainly focused on the risks of over-exposure due to ozone depletion from man-made chlorofluorocarbons (CFCs). Thanks to the virtual elimination of CFC emissions as a result of the Montreal Protocol, the CFC burden in the atmosphere is beginning to decline and the first signs of ozone recovery are now being detected over both polar and mid-latitude regions. However, climate change will have its own impact on the ozone layer. In particular, a warming climate is predicted to cause a strengthening of the stratospheric Brewer-Dobson circulation, especially in the Northern Hemisphere. In this talk I will show how this would affect the transport of ozone in the stratosphere and its spatial distribution, leading to an increase in the flux of stratospheric ozone into the troposphere, and altering expected UV levels at the Earth’s surface. For example, in northern middle to high latitudes surface UV is expected to decrease as a result of climate change, which could adversely affect human health through a decrease in Vitamin D production. These and other potential impacts on human beings and the natural environment will be briefly discussed.