More than 20 scientific experts have written to the UN food agency expressing shock at its failure to review or retract a report on livestock emissions that two of its cited academics said contained “multiple and serious errors”.
The alleged inaccuracies are understood to undermine the potential of dietary change to reduce agricultural greenhouse gases, which account for about a quarter of total anthropogenic emissions and mostly derived from livestock.
In the joint letter, seen by the Guardian, the scientists say they are dismayed that the UN’s Food and Agriculture Organization (FAO) has failed to correct “serious distortions” originally identified by academics Paul Behrens and Matthew Hayek has been identified, which the Guardian reported on earlier this year.
Behrens and Hayek say a separate complaint briefly got. They say a “technical dialogue” promised by the FAO never materialized beyond an invitation to a muted webinar where they could type questions into a Q&A box.
“There was no serious reaction,” Behrens said. “They partially addressed one of the points in the webinar in an unscientific way. But they have not responded at all to the vast majority of our complaints. Our concerns are barely acknowledged, let alone seriously engaged with. It was like hitting a brick wall. The FAO has made serious mistakes that urgently need to be corrected in order to maintain its scientific credibility.”
One of the letter’s signatories, Jennifer Jacquet, a professor of environmental science and policy at the University of Miami, compared the FAO’s complaint process unfavorably to that of a scientific journal, “where you at least get a correction of the article could expect.” .
The FAO’s “Pathways to Lower Emissions” study was originally billed as “an updated comprehensive overview” of global livestock emissions and was launched at last December’s Cop28 climate summit.
Behrens and Hayek said they inappropriately used their work on now-outdated nationally recommended diets (NRDs), double-counted meat emissions, mixed different base years in analyses, and omitted the opportunity cost of carbon sequestration on non-farmed land.
Correspondingly, the emission savings from farming fewer livestock were underestimated by a factor of between six and 40, Hayek estimated.
In an initial response to complaints, seen by the Guardian, the FAO’s chief scientist, Beth Crawford, described the report’s NRD-based emissions forecast for 2050 as “a rough estimate”. She said: “This methodological choice was made because there is no global database on dietary preferences and no policy instrument supporting the adoption of alternative diets based on balanced environmental, economic and social criteria.”
She did not touch on other points raised by the pair, such as alleged double counting and mixed baseline years, which Hayek said were “related to their misuse of our scientific data”.
Crawford’s response said the FAO had received a “rigorous and thorough review” supporting its conclusions from a group of scientists led by three named academics.
The joint letter, which was also signed by 78 environmental groups, said: “It is unacceptable that the FAO, a respected UN institution, dismisses these serious errors as a ‘rough estimate’ when the data and policy recommendations it provides , is so internationally influential. A higher standard of scientific rigor is required.”
Jacquet said: “It seems clear to me that some of the choices the FAO made in their methodology were just there to maintain the status quo of increasing meat production and consumption.”
The FAO has been contacted for a response.
