The ozone hole was caused by chemicals formerly used in air conditioners and refrigerators. But new research shows that the same stuff is also behind half of the warming the Arctic experienced between 1955 and 2005.
The study, published in Nature Climate Change on Monday, uses a number of climate models to figure out how much these substances have impacted the Arctic’s temperature rise, as well as sea ice loss. If there’s any silver lining, it shows that the efforts to phase them out in the late 1980s was a good idea for the ozone layer and the climate.
Researchers used 1955 as a jumping off point because the use of ozone-depleting substances like chlorofluorocarbons and hydrochlorofluorocarbons as refrigerants rose steeply thereafter. They ran the models under two scenarios. In one, emissions followed the trajectory they did over the next 50 years while in another, ozone-depleting substances were kept at 1955 levels. The results showed that under the business as usual scenario, the annual average global temperature increased by 0.59 degrees Celsius (1.1 degrees Fahrenheit). However, in the models without these substances, the increase was only 0.39 degrees Celsius (0.7 degrees Fahrenheit). That means that these substances are responsible for a third of global warming during this time period.