Hotter temperatures by 2100 could slash global GDP by more than 20%, according to new research, and the way the economic impact will be distributed threatens to turn climate change into an enormous driver of worldwide inequality. A new analysis of the relationship between heat and economic performance released this week by Oxford Economics, a global forecasting firm, identified a divide between nations on either side of 15° Celsius (59° Fahrenheit), the “global sweet spot” for economic activity. A country whose average annual temperatures today are cooler than 15° C, including those in North America and Europe, stand to benefit slightly in the short term from rising temperatures. Tropical and subtropical countries whose average temperatures are already warmer than 15° C today, including the entire global South, face catastrophic economic degradation.
The new analysis is an independent update to a landmark 2015 study in the journal Nature that introduced the technique for projecting the economic impacts of a hotter world. The top-line result—a 21% global GDP hit by 2100—is in line with the original work. The updated research includes an additional decade of data and 40 more countries, bringing the total under analysis to 203. The original study has become influential tool, now that mainstream economists are building scientific projections of global warming into models of growth. The original 2015 study has gone on to inform the International Monetary Fund’s climate work and many others’.