The economic commitment of climate change | Leonie Wenz
Leonie will be discussing the paper The economic commitment of climate change.
‘Global projections of macroeconomic climate-change damages typically consider impacts from average annual and national temperatures over long-time horizons. Here, we utilize recent empirical findings from more than 1600 regions worldwide over the past 40 years to project sub-national damages from temperature and precipitation including daily variability and extremes. Using an empirical approach which constrains the persistence of impacts on economic growth rates, we find that the world economy is committed to an income reduction of 21% within the next 25 years due to historical carbon emissions and socioeconomic inertia (relative to a baseline without climate impacts, likely range of 13-29% accounting for physical climate and econometric uncertainty). These damages already outweigh the mitigation costs required to limit global warming to two degrees by sevenfold over this near-term timeframe, and thereafter diverge strongly dependent on emission choices. Committed damages arise predominantly through changes in average temperature, but accounting for further climatic components raises estimates by approximately one third and leads to stronger regional heterogeneity. Committed losses are projected for all regions except those at very high latitudes, where reductions in temperature variability bring strong benefits. The largest losses are committed at lower latitudes in regions with lower cumulative historical emissions and lower present-day income.’