Projections of hydrofluorocarbon (HFC) emissions and the resulting global warming based on recent trends in observed abundances and current policies

Abstract. The emissions of hydrofluorocarbons (HFCs) have increased significantly in the past 2 decades, primarily as a result phaseout ozone-depleting substances under Montreal Protocol and use HFCs their replacements. In 2015, large increases were projected HFC this century absence regulations, contributing up to 0.5 ?C global surface warming by 2100. 2019, Kigali Amendment came into force with goal limiting globally, currently, regulations limit are effect several countries. Here, we analyze trends inferred from observations atmospheric abundances compare them previous projections. Total CO2 eq. continue increase through 2019 (to about 0.8 GtCO2eq.yr-1) but 20 % lower than previously for 2017–2019, mainly because HFC-143a. This indicates that used much less industrial commercial refrigeration (ICR) applications projected. is supported data reported developed countries consumption HFC-143a China. Because time period preceded beginning provisions, reduction cannot be linked directly provisions Amendment. However, it could indicate companies transitioned away its high potential (GWP) ICR anticipation national or mandates. There two new scenarios based (1) on current Kigali-independent (K-I) control policies currently existing (2) compliance (KA-2022). These reduce 2050 calculated 4.0–5.3 GtCO2eq.yr-1 1.9–3.6 GtCO2eq.yr-1. added further 0.9–1.0 2050. Without any controls, projections suggest contribution 0.28–0.44 2100, compared temperature 0.14–0.31 considering K-I place. Warming additionally limited controls 0.04