Shrinking Ozone Hole
- Ahn
- Jul 3, 2016
- 2 min read
According to National Geographic, the ozone layer is a thin layer of the stratosphere consisting of ozone molecules. These molecules serve as a sort of shield for Earth's lifeforms because they absorb radiation, mainly UV light.
There are two types of ultraviolet light, UVA and UVB. Ultraviolet B is the cause of minor conditions such as sunburns and a few cancers while Ultraviolet A has been linked to deeper cancers such as melanoma and premature aging. That's not to say that Ultraviolet B is harmless compared to Ultraviolet A though because it prevents the reproductive cycle of a vital organism to our entire biosphere, phytoplankton.
The main cause of ozone destruction are chemicals labelled as ODCs or ozone-depleting substances. These chemicals are widely used because they are cheap and nonlethal to organisms. Unfortunately, the chlorine or bromine they often contain is released into the atmosphere where even a single molecule of chlorine can destroy thousands of ozone molecules.
An ozone hole is not necessarily a hole but an area where ozone levels are dramatically lower than where they should be. The ozone hole was first discovered in 1950s and, after discovering a drop in the 1980s, scientists have kept track of it ever since.
On the 16 of September in 1987, the Montreal Protocol was agreed on. This document limits the use of chemicals that contribute to ozone depletion and almost every country in the world signed it in order to rally against the ever growing ozone hole. A study recently released by MIT reveals that our efforts have had a significant effect on the ozone layers.
Susan Solomon, the Ellen Swallow Richards Professor of Atmospheric Chemistry and Climate Science at MIT, Diane Ivy, research scientist in the Department of Earth, Atmospheric and Planetary Sciences, and researchers at the National Center for Atmospheric Research in Boulder, Colorado, and the University of Leeds in the U.K studied the ozone layer and kept track of other atmospheric conditions from 2000 to 2015. From this date they've discovered that the ozone hole has shrunk by 4 million square kilometers since 2000. At this rate, we will have healed our ozone layer by midcentury if we are careful.
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