Major climate change report retracted – a year later

A blockbuster climate-economics study that shaped international policy has been formally retracted by the journal Nature after researchers acknowledged significant data flaws and methodological errors that dramatically inflated projected economic damages from climate change.

“The economic commitment of climate change,” authored by Maximilian Kotz, Anders Levermann, and Leonie Wenz of the Potsdam Institute for Climate Impact Research in Germany, was published April 17, 2024, and quickly became one of the most influential climate studies of the decade.

It accumulated more than 300,000 online views, drew over 226 scholarly citations, and was incorporated into assessments by the Network for Greening the Financial System, the OECD, and even a US Congressional Budget Office analysis on climate risk.

But on Dec. 3, Nature announced that the paper has now been fully retracted at the authors’ request.

The original study attempted to quantify how temperature and precipitation changes have historically affected national economic growth from 1960–2019, and then used that relationship to project damages through the 21st century under various emissions scenarios.

Its headline findings stunned both researchers and policymakers, predicting:

• 19% loss of global income by 2050, roughly $38 trillion annually.

• Up to 62% loss of global GDP by 2100 under high-emissions trajectories, more than triple many previous estimates.

• Severe impacts concentrated in poorer, hotter regions such as sub-Saharan Africa and South Asia.

The authors said that climate damages were so large and so likely that, with 99% probability, they would exceed adaptation and mitigation costs by mid-century. In other words, there was no going back from the damage that climate change has wrought.

Major media outlets amplified these conclusions. Advocates cited the findings as evidence of the catastrophic economic stakes of inaction. But questions soon followed.

The unraveling began after Stanford economist Solomon Hsiang and colleagues published a formal critique in Nature in August. They found that a single country’s flawed data distorted the entire model. Economic statistics from Uzbekistan (1995–1999), which was a period marked by measurement anomalies, had been fed into the model without correction. Those errors significantly pushed global estimates upward. When Uzbekistan was removed, the projected 2100 GDP loss fell from 62% to 23%, a number far more consistent with the broader climate-economics literature.

The model also understated uncertainty. By failing to account for spatial autocorrelation, the tendency of nearby regions to experience related economic and climate patterns,the study presented overly confident ranges. When corrected, mid-century losses widened from 11–29% to 6–31%, and the probability that climate damages would exceed mitigation costs by 2050 dropped from 99% to 90%.

Critics argued that relying heavily on historical weather shocks, without fully capturing human adaptation or long-run resilience, biased results upward.

The authors agreed. In their retraction note, they wrote that the revisions created “discrepancies in the estimates for climate damages by mid-century” and that the errors were “too substantial for a correction.”

They have since uploaded a revised, non-peer-reviewed version online and intend to resubmit a corrected analysis.

The episode comes as scientific retractions are rising industry-wide as climate-economics modeling, in particular, faces intense scrutiny, as governments and financial institutions increasingly rely on forecasts to shape energy policy, regulatory frameworks, and long-term investment planning.