Climate Change May Alter UV Levels around the Globe
08.09.2009 - Atmosphere & Space, Human Dimension, Other, Arctic, Antarctic
While the use of ozone-damaging chlorofluorocarbons (CFC's) was phasedout under the 1987 Montreal Protocol, man-made climate change has the potential togreatly affect the ozone layer as well, not through ozone depletion but by influencing the movement of high-altitude winds, according to a recent study conducted by researchers at the University of Toronto and published in Nature Geoscience.
Michaela Hegglin, an atmospheric physicist at the University of Toronto, and co-author Theodore Shepperd devised a computer model which looks at the consequences of warmer surface temperatures on an atmospheric pumpcalled the Brewer-Dobson circulation, which drives ozone around theworld through high-altitude winds.
The model predicts that during the period between 1965 and 2095, placesin the far Northern Hemisphere above 60°N such as Alaska, Canada,Scandinavia and Russia could see a 9.1% drop in UV radiation, while in thenorthern mid-latitudes UV levels will drop by 3.6 % and rise in thetropics by 3.8%. Below 60°S in the Southern Hemisphere - which is essentially the Continent of Antarctica - average UV levels will increase by 3.2%, although during the austral spring and summer they could increase by as much as 20%, equivalent to nearly half the ozone hole caused by CFC's.
Exposure to high levels of UV can provoke skin cancer, damage cataracts in the eyes and lead to crop damage, whereas low exposure can lead to Vitamin D deficiency. Growing ozone levels in the troposphere (near the surface of the Earth) might include reduced air quality, the reinforcement of the warming cycle and additional health problems for people with respiratory diseases.
