I TALKED last month about the ozone hole that’s developed over the Arctic, which is certainly big news. I warned you not to move to Alaska or even the northern United States because the Arctic ozone hole has wanderlust and those holes let in excessive amounts of ultra-violet radiation – not a good thing for human skin.
But the developing ozone holes are over the poles and those pesky holes don’t affect us here, right? Well, that’s what I always thought until I learned about research done by scientists at Columbia University's School of Engineering and Applied Science. They reported in the journal Science that the Antarctic ozone hole has affected the atmospheric circulation of the entire southern hemisphere all the way to the equator.
Previous work had shown that the ozone hole changes the atmospheric flow at higher latitudes, but this new study demonstrates that the ozone hole can also influence tropical circulation and bring increased rainfall near the equator. This is the first time that ozone depletion, an upper atmospheric phenomenon confined to the polar regions, has been linked to climate change from the pole to the equator. The ozone hole is now widely believed to have been the dominant agent of atmospheric circulation changes in the southern hemisphere in the last 50 or 60 years.
In case you need some background, the ozone layer is located in Earth's stratosphere and it absorbs most of the Sun's harmful ultraviolet rays. Since the 1950s, widespread use of chlorofluorocarbons (CFCs) has significantly and rapidly broken down the molecule ozone and caused a hole to develop in the Antarctic ozone layer. Global CFC production was phased out in the 1990s and scientists have observed over the past decade that ozone depletion has largely halted. The scientists have great hopes that the ozone holes will close by midcentury.
But as I mentioned last month, we are still messing with things we don’t understand and can’t control, and even if the ozone hole does close in 2050 or so (and there’s some debate about that), these new findings suggest that in the 50 years or so until this happens, the ozone holes are going to have a considerable impact on climate.
So are we being affected here? I’ve lived here for 30 years and it seems to me that the wet season is a lot drier than it used to be and the dry season is a lot wetter. Manny Sikau, a traditional navigator, has told me that the weather lore his grandfather taught him doesn’t seem to work as well any more. He said he was afraid he was forgetting what his grandfather had taught him. I told him I suspected that wasn’t the problem.
Climate change. Up close and personal!
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