There’s a common misconception that climate change and the depletion of our ozone layer are closely linked. Actually, one survey reveals plenty of misconceptions about climate change:
“Majorities of Americans … incorrectly believe that the hole in the ozone layer, toxic wastes, aerosol spray cans, volcanic eruptions, the sun, and acid rain contribute to global warming.”
Climate change and ozone depletion are better thought of as distinct issues. Briefly …
- Climate change is happening because our planet is warming, caused predominantly by a rise in greenhouse gases (carbon dioxide, methane, nitrous oxide) in the atmosphere, which trap heat from escaping our Earth’s surface.
- Stratospheric ozone depletion is happening because there has been a rise in ozone-depleting substances. Since stratospheric ozone blocks a large amount of UV radiation, ozone depletion leads to more UV radiation reaching the Earth, which will cause harm to us and other living organisms.
However, a recent study published in Science by Anderson and his colleagues now provides a clear link between the two issues. Their study finds that strong storms have the ability to take moisture very high into the atmosphere, creating conditions that speed up the process of ozone destruction. If the frequency of convective storms were to increase, the amount of ozone in the stratosphere would decline … leading to higher amounts of UV radiation reaching the Earth’s surface. A press release explains the connection this way …
“In the system described by Anderson and his team, water vapor injected into the stratosphere by powerful thunderstorms converts stable forms of chlorine and bromine into free radicals capable of transforming ozone molecules into oxygen. Recent studies have suggested that the number and intensity of such storms are linked to climate changes, Anderson said, which could in turn lead to increased ozone loss and greater levels of harmful UV radiation reaching the Earth’s surface, and potentially higher rates of skin cancer.”
In more simplified terms …
Climate change = more powerful storms = more ozone depletion = greater UV radiation = higher cancer rates
This is a relatively long string of steps, but not uncommon when discussing atmospheric changes. We’re not dealing with a simple system, so it’s not a simple topic to try and explain. In addition, the way that climate change research is communicated in the media (and by scientists) isn’t always so clear. As one study of our society’s knowledge of climate change puts it:
“It is urgent that climate scientists improve the ways they convey their findings to a poorly informed and often indifferent public. “
It’s not surprising that there is confusion out there about how all the changes happening in our climate system are related to each other. Even though there is scientific certainty about the basic processes of climate change and ozone depletion, we’re still figuring out some of the complexities.
Read more … NYTimes article: Storms Threaten Ozone Layer Over U.S., Study Says
Anderson, James G., et al. “UV dosage levels in summer: increased risk of ozone loss from convectively injected water vapor.” Science 337.6096 (2012): 835-839.
Photo credit: NASA