The large contribution of projected HFC emissions to future climate forcing

The consumption and emissions of hydrofluorocarbons (HFCs) areprojected to increase substantially in the coming decades in re-sponse to regulation of ozone depleting gases under the MontrealProtocol. The projected increases result primarily from sustainedgrowth in demand for refrigeration, air-conditioning (AC) andinsulatingfoamproductsindevelopingcountriesassumingnonewregulation of HFC consumption or emissions. New HFC scenariosare presented based on current hydrochlorofluorocarbon (HCFC)consumption in leading applications, patterns of replacements ofHCFCsbyHFCsindevelopedcountries,andgrossdomesticproduct(GDP) growth. Global HFC emissions significantly exceed previousestimatesafter2025withdevelopingcountryemissionsasmuchas800% greater than in developed countries in 2050. Global HFCemissions in 2050 are equivalent to 9–19% (CO