Scientists criticise UN agency’s failure to withdraw livestock emissions report

The emissions savings from farming less livestock were underestimated by a factor of between six and 40, Mr Hayek estimated.

More than 20 scientific experts have written to the UN’s food agency, expressing shock at its failure to revise or withdraw a livestock emissions report that two of its cited academics have said contained “multiple and egregious errors”.

The alleged inaccuracies are understood to have downplayed the potential of dietary change to reduce agricultural greenhouse gases, which make up about a quarter of total human-caused emissions and mostly derive from livestock.

In the joint letter, the scientists say they are dismayed that the UN Food and Agriculture Organisation (FAO) has failed to remedy “serious distortions” originally identified by the academics Paul Behrens and Matthew Hayek.

Behrens and Hayek say a separate complaint has received short shrift. They say a “technical dialogue” promised by the UN organisation never materialised beyond an invitation to a muted webinar where they could type questions into a Q&A box.

“There has been no serious response,” Mr Behrens said.

“They partially addressed one of the points in the webinar in an unscientific way, but they gave no response at all to the vast majority of our complaints.

Our concerns have barely been acknowledged, let alone seriously engaged with

"It’s been like hitting a brick wall. The FAO has made grievous errors that need urgent correction to maintain its scientific credibility.” 

One of the signatories to the letter, Jennifer Jacquet, a professor of environmental science and policy at the University of Miami, compared the FAO’s complaints process unfavourably with those of a science journal, “where you could at least expect a correction to the article”.

The FAO’s “pathways toward 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.

Mr Behrens and Mr Hayek said it inappropriately used their work on now outdated nationally recommended diets (NRDs), double-counted meat emissions, mixed different baseline years in analyses, and omitted the opportunity cost of carbon sequestration on non-farmed land.

Correspondingly, the emissions savings from farming less livestock were underestimated by a factor of between six and 40, Mr Hayek estimated.

In an initial response to complaints, the organisation’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 that supports 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 Mr Hayek said “are related to their misuse of our scientific data”.

• Guardian