In April 2024, the scientific journal Nature published a study according to which climate change would cause much greater economic damage by the end of the century than previous estimates suggested. The conclusion gained headlines and global repercussions and was incorporated into risk management scenarios used by central banks.
Last Wednesday (3), Nature retracted the study.
The decision came after a group of economists identified problems in the data referring to a country, Uzbekistan, which significantly distorted the results. Without Uzbekistan, they concluded, the damage is in line with what previous research indicated. Instead of a 62% drop in global GDP by 2100 in an unchanged emissions scenario, the reduction would be 23%.
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Still, eliminating more than 20% of global economic activity would be a severe shock. Critics of the study emphasize that climate change remains a relevant threat and that it is necessary to advance measures to combat it. But they say atypical results should be treated with skepticism.
The study was led by Leonie Wenz, an economist at the Potsdam Institute for Climate Impact Research, in Germany, and Maximilian Kotz, then a postdoctoral researcher at the institution. The team developed novel techniques to more comprehensively capture the economic consequences of global warming.
They used a dataset built over years, with information about economic conditions in areas smaller than countries, such as states and provinces. They incorporated different climate variables, such as rainfall volume and heat waves, and not just average temperatures. They also considered effects of extreme weather events over a decade, rather than assuming they disappeared quickly.
“We wanted to understand how long we were able to observe these impacts in the data,” said Wenz. “This led to greater damage magnitudes compared to those from work that did not consider these persistent effects.”
This also provided a stark contrast to the costs of avoiding catastrophic warming. The damages already contracted for the next 25 years would cost six times more than necessary to reduce emissions and limit global warming to 2 degrees Celsius, the goal of the Paris Agreement.
In response to criticism, Kotz and Wenz made corrections that they said changed the results only modestly, with a slightly larger range of uncertainty and slightly smaller economic impact until the end of the century.
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They plan to review the study and resubmit it.
