Economic bite of climate change could be even bigger than we thought

Climate change could cause ten times as much damage to the global economy than previously predicted, analysis of previous climatic fluctuations suggests.

Typical climate studies have looked at economic projections for a warming planet, with the post-climate change reality compared to a control temperature. Researchers at Stanford University and the University of California, Berkeley departed from this norm and first established what optimal economic outputs were during historically more temperate years. They surveyed 166 countries using data from 1960 to 2010, then compared that peak performance with years when the weather was more extreme. 

The results paint a much more dramatic picture of a warmer planet than previously envisioned. 

"If you have a lot of data on a lot of countries in a lot of years, that allows you to start to distinguish the particular role of temperature in economic performance," said Stanford's Marshall Burke, the co-lead author in an interview with Bloomberg. 

Countries facing already hotter than the optimal temperature – of about 55 degrees Fahrenheit – are likely to fare worse economically from climate change, according to the paper. Temperature is blind to traditional measurements of economy standing; rich or poor, agricultural or industrial, rising temperatures are take an economic toll. Climate change, the researchers say, will dramatically impact economies worldwide. 

Thomas Sterner, an environmental economist at the University of Gothenburg in Sweden who was not part of the study, writes in a companion commentary article that if the study withstands scrutiny, it will have "wide-reaching implications."

Mr. Sterner cites two examples: if warming continues on its projected 4.3 degrees Celsius average increase worldwide by 2100, economies can anticipate a quarter loss in income compared to a world that experiences no warming. 

Sterner also warns that "global income will become more unequal" as different regions "benefit (particularly those that have a cold climate today, which tend to be countries with quite high incomes) whereas others, especially the (warmest and) poorest, would be hit very hard."

"Climate is not fate," Mr. Burke told Bloomberg. "Countries can do a lot, and there many other factors beyond temperature that matter," such as geography, culture, and government.