According to scientific theory, the formation of an ozone hole in the Earth's stratosphere is associated with the release of chemicals that were previously used in air conditioners and refrigerators. New research shows that these same substances are responsible for 50% of the warming in the Arctic between 1955 and 2005.
After 1955, the use of ozone-depleting substances such as chlorofluorocarbons and hydrochlorofluorocarbons as refrigerants increased dramatically. To find out how these substances contributed to the rise in temperature and the loss of sea ice in the Arctic, scientists conducted climate modeling according to two scenarios. In one of them, the level of emissions over the next 50 years corresponded to reality, while in the other, ozone-depleting substances remained at the 1955 level throughout this period.
The results showed that in a real scenario, the average annual temperature in the world increased by 0.59 ° C, while in models without an increase in emissions, the temperature increase was only 0.39 ° C. It turns out that these substances are responsible for a third of the level of global warming during the period under consideration.
In the Arctic, where warming is occurring at an accelerated pace, the temperature rise in the conditions of chemical emissions over 50 years was 1.59 ° C, and keeping them at the 1955 level would lead to a warming of only 0.8 ° C, which is half that. The study also attributed half of the September losses of Arctic sea ice over this period to these substances.
In 1989, the Montreal Protocol entered into force, which provided for the phase-out of chemicals that deplete the ozone layer. The measures taken proved to be effective, and the ozone hole could close already this century. Reducing them further could also help prevent extreme warming in the Arctic, although some of the replacements for legacy refrigerants are greenhouse gases.
The research is published in the journal Nature Climate Change.