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A major paper purporting to show the economic devastation of climate change has been retracted after researchers noticed errors in the data that dramatically skewed the results. The peer-reviewed paper, published in Nature in 2024, was the second-most referenced climate paper that year, being cited by the U.S. Congressional Budget Office, the World Bank, and the Network for Greening the Financial System (NGFS), an international network of financial regulators.

The paper, “The Economic Commitment of Climate Change,” examined data from some 1,600 regions around the world over the past four decades to predict catastrophic economic consequences. The authors, who were associated with Germany’s Potsdam Institute for Climate Impact Research, predicted a 19% decrease in global income by 2050 and a 62% decline in global economic output by 2100.

An ‘Insane’ Conclusion Based on Inaccuracies

“Most people for the last decade have thought that a 20% reduction in 2100 was an insanely large number,” said Stanford University professor Solomon Hsiang, who wrote a critique of the study. “So the fact that this paper is coming out saying 60% is off the chart.”

But the eye-popping number did not dissuade the NGFS from incorporating the paper into its framework. The NGFS creates climate scenarios that banks such as JP Morgan use to “identify, measure, monitor and manage climate-related financial risks.” In plain English, this means the NGFS convinces banks to hold onto a larger share of their assets for fear that climate change will affect future economic performance.

As it turned out, this paper’s conclusion was an outlier because it was just plain wrong, according to the time-tested principle: “Garbage in, garbage out.” Other researchers noted “inaccuracies… in the underlying economic data for the period 1995–1999” for the central Asian nation of Uzbekistan, according to Nature’s retraction notice.

Somehow, those minor errors were magnified in a massively skewed result. If researchers removed Uzbekistan data entirely, their model showed a global economic decline of 23% by the end of the century, instead of a decline of 62%.

“The authors corrected the data from Uzbekistan for 1995–1999,” Nature reported. “The authors acknowledge that these changes are too substantial for a correction, leading to the retraction of the paper. … The authors intend to submit a revised version of the paper for peer review.” In the meantime, Nature provided a link to an edited version of the original paper.

It’s difficult to fathom how such a major error could happen. For a study examining data from 1,600 regions, how could erroneous data from one small country nearly triple the final result? Uzbekistan is one of only two doubly landlocked countries in the world (meaning that all its neighbours are also landlocked), and it is currently responsible for only 0.14% of global GDP. It should have a minuscule effect on the final result, unless the authors gave it undue weight.

A History of Errors

The error illustrates the fact that papers predicting economic conditions 75 years into the future must rely on extrapolation and inference, and such a paper’s result is only as trustworthy as its worst guess.

Scientists have been making horrible predictions for at least 100 years. Malthusian predictions of global overpopulation leading to mass starvation helped spawn the eugenics movement. But those fears were unfounded because technological innovation simply allowed the world’s farmers to grow more food. After that came hysterical predictions of “peak oil” and other key resources, based on current production and known reserves. But this too proved illusory as oil exploration and technological innovation tapped into new sources.

In recent decades, fashionable science has predicted ecological and economic disaster, based on a tenuous link between manmade carbon-dioxide emissions and rising global temperatures. But these predictions assume a comprehensive understanding of world ecology that researchers simply cannot claim. It is highly likely that some unforeseen factor will throw off their calculations or, in the alternative, that societies will learn to adjust to changing conditions.

This fashionable science is often used to push restrictive economic policies that seek to shut down fossil fuel use, thereby making energy production much more expensive. The authors of the retracted study argue that the “damages [of climate change] already outweigh the mitigation costs required to limit global warming to two degrees by fivefold over this near-term timeframe.” Without knowing all the economic damage they attribute to climate change, this author is highly skeptical that such damage is only one-fifth of the cost of steering the whole economy away from fossil fuels in just a couple of decades (which is what scientists claim is required to limit global warming to two degrees).

It’s also difficult to fathom how such a major error made it through the peer review process. Perhaps this peer-review process is not as robust as its gatekeepers would like non-experts to believe. (In fairness, both Nature and the study’s authors do deserve credit for their transparency in taking responsibility once the error was pointed out to them.) This retraction serves as another reminder to take so-called expert opinion with a grain of salt. Experts are also human. They too can make mistakes, sometimes massive ones.

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Republished with thanks to The Washington Stand. Image via Adobe.