Ozone-depleting gases might have driven extreme Arctic warming

> England and his colleagues compared climate simulations both with and without the mass emission of CFCs that began in the 1950s. Without CFCs, the simulations showed an average Arctic warming of 0.82 °C. When the presence of ozone-depleting compounds was factored in, that number jumped to 1.59 °C. The researchers saw similarly dramatic changes in sea-ice coverage between the two sets of model simulations. By running the models with fixed CFC concentrations while varying the thickness of the ozone layer, the team was able to attribute the warming directly to the chemicals — rather than changes these substances caused in the ozone layer.

Interesting to see such fundamental and potentially paradigm-changing studies come to light now. About half of the Arctic warming could be due to CFC's. And, strangely enough, not due to ozone depletion, but rather the CFCs themselves.

Later:

> ... A stronger argument could be made, she [scientist at Goddard] continues, if the team had been able to provide a clear physical explanation for the modelled amplification.

It's also not clear from the article whether only the Arctic itself was modeled, or if the effect is restricted to the Arctic specifically.

One more thing isn't clear: whether the model accounts for decompositions of CFCs, and the effect of the resulting byproducts on temperature.

The research paper's abstract doesn't offer an answer:

https://www.nature.com/articles/s41558-019-0677-4

If this is true, it has massive implications on a lot of the runaway scenarios that have been talked about.