Early action on HFCs mitigates future atmospheric change

As countries take action to mitigate global warming, both by ratifying theUNFCCCParis Agreement
and enacting the Kigali Amendment to the Montreal Protocol to manage hydrofluorocarbons (HFCs),
it is important to consider the relative importance of the pertinent greenhouse gases and the distinct
structure of their atmospheric impacts, and how the timing of potential greenhouse gas regulations
would affect future changes in atmospheric temperature and ozone. HFCs should be explicitly
considered in upcoming climate and ozone assessments, since chemistry-climate model simulations
demonstrate that HFCs could contribute substantially to anthropogenic climate change by the mid-
21st century, particularly in the upper troposphere and lower stratosphere i.e., global average warming
up to 0.19 Kat 80 hPa. The HFCmitigation scenarios described in this study demonstrate the benefits
of taking early action in avoiding future atmospheric change: more than 90% of the climate change
impacts of HFCs can be avoided if emissions stop by 2030.