Currently— April 28th, 2022
What you need to know, currently.
In the 1980s there was a brief moment, outlined quite eloquently by Nathaniel Rich in his massive New York Times piece, Losing Earth, when it looked like government action on climate change was imminent.
Scientists had discovered a “hole” in the ozone layer, although there was no technical hole and on some level, they had really discovered the power of metaphor. Ozone is a gas made up of three oxygen atoms. It generally floats around the stratosphere, protecting the earth from ultraviolet radiation. When encountered in the troposphere (the ground-level atmosphere) it becomes harmful—causing breathing difficulties for humans and animals, as well as damaging plant life.
The ozone hole was a compelling image and it grabbed attention, but what it described, is really a thinning of ozone in the upper atmosphere—caused in large part by chlorofluorocarbons, or CFCs, which were used to make aerosol sprays, solvents, and refrigerants.
When the Montreal Protocol was enacted, all member states of the United Nations agreed to strictly control emissions of CFCs that were causing ozone thinning.
But new research from UC Riverside indicates that lower-level ozone may be more of a problem than scientists realized.
This new study, published in Nature Climate Change, found that ozone changes—namely the decrease in the upper atmosphere and increase in the lower—has caused about 30 percent of ocean warming between 1955 and 2000. They attributed about 60 percent of that warming to tropospheric ozone—which is caused by things like pesticides, tobacco smoke, and auto exhaust.