The role of HFCs in mitigating 21st century climate change
There is growing international interest in mitigating climate change during the early part of this century by reducing emissions of short-lived climate pollutants (SLCPs), in addition to reducing emissions of CO 2. The SLCPs include methane (CH 4), black carbon aerosols (BC), tropospheric ozone (O 3) and hydrofluorocarbons (HFCs). Recent studies have estimated that by mitigating emissions of CH 4, BC, and O 3 using available technologies, about 0.5 to 0.6 °C warming can be avoided by mid-21st century. Here we show that avoiding production and use of high-GWP (global warming potential) HFCs by using technologically feasible low-GWP substitutes to meet the increasing global demand can avoid as much as another 0.5 °C warming by the end of the century. This combined mitigation of SLCPs would cut the cumulative warming since 2005 by 50% at 2050 and by 60% at 2100 from the CO 2-only mitigation scenarios, significantly reducing the rate of warming and lowering the probability of exceeding the 2 °C warming threshold during this century.