For the last four years, media outlets such as The New York Times, the Los Angeles Times, and Fox News have repeatedly cited a United Nations study which found that livestock production is responsible for about 18 percent of global greenhouse-gas emissions—a larger share than comes from all planes, trains, and automobiles combined.

Last week, news outlets revisited those claims, following a talk delivered by Dr. Frank Mitloehner, an animal scientist based at UC Davis, at an American Chemical Society meeting last Monday. Mitloehner criticized the conclusions of a 2006 report from the U.N. Food and Agriculture Organization, “Livestock’s Long Shadow.” The study’s assertion that meat (including eggs, dairy, and other animal protein) production is responsible for more greenhouse-gas emissions globally than the transportation industry is certainly untenable, and likely false, he said.

The problem Mitloehner highlighted is that the FAO performed what’s called a full “lifecycle analysis” for the livestock industry. In other words, it added up emissions from things like fertilizer production and land-use change in addition to those from cow burps and manure. It did not do the same for the transportation industry, however, tabulating the emissions from fossil-fuel combustion, but not from automobile manufacturing or road construction, for instance. Mitloehner has spent the last week explaining to reporters that this led to a classic apples-to-oranges comparison between the two sectors. In one of the first news articles on the subject, the FAO substantiated this criticism, saying that its comparison was indeed flawed.

“I must say honestly that he has a point – we factored in everything for meat emissions, and we didn’t do the same thing with transport, we just used the figure from the [Intergovernmental Panel on Climate Change],” FAO livestock policy officer Pierre Gerber, a co-author of “Livestock’s Long Shadow,” told the BBC. “But on the rest of the report, I don’t think it was really challenged.”

Unfortunately, most articles did not do a good job covering the rest. As the Knight Science Journalism Tracker astutely observed:

Some reports, however, interpret the asserted flaw and the concession from one of the UN-affiliated authors that it holds water to mean that climate science and climate worry has been stripped further of legitimacy. Which is to say, by implication, if it’s not climatically worse than using cars and other vehicles, then eating meat is as green as a bean sprout.

Few reporters, however, seem to have the wit to have homed in on the 18 percent figure. If that’s right, it’s a lot. If the figure is a serious overestimate, that’s a story. But to make the story only whether transport or meat are bigger boosts to the greenhouse is lazy.

In fact, some of the coverage displayed worse flaws than a narrow focus on the relative emissions of livestock and transportation. Not only did most reporters not scrutinize the 18 percent figure, some totally mischaracterized Mitloehner’s opinions about it. Rather than reporting that he thinks it might be an overestimate, they left the impression that he believes there is no link whatsoever between livestock production and warming. For example, Fox News misled readers in the second paragraph of its article:

The largely reported link between global warming and cattle farming — propagated by a United Nations report on “Livestock’s Long Shadow” — was also largely inaccurate, explains one scientist.

Fox News’s headline, “Eat Less Meat, Reduce Global Warming – Or Not,” while not glaringly wrong, was also inaccurate. Mitloehner does not think curtailing livestock reduction would make no dent in warming; he just thinks it would be an insignificant dent and that there are far more effective ways to reduce emissions. (A glaringly wrong headline, by the way, would be the one in The Washington Times, which read, “Meat, dairy not tied to global warming.”)

Some of the confusion seems to trace back to a press release from the American Chemical Society after Mitloehner’s talk at one of its meetings. The release quoted him saying, “We certainly can reduce our greenhouse-gas production, but not by consuming less meat and milk. Producing less meat and milk will only mean more hunger in poor countries.”

Mitloehner believes his original quote was slightly different, and his main concern is that the FAO’s flawed assertion that livestock accounts for more emissions than transportation will lead policymakers and consumers to make the wrong choices.

“I didn’t say that there is no reduction in greenhouse gases associated with animal protein consumption, but that it is a relatively small contribution and that consumers can do other things that have greater impact on this,” he said in an interview.

(Mitloehner’s talk was based on a peer-reviewed paper he co-authored last fall. The press release issued by UC Davis noted that the report “was supported by a $26,000 research grant from the Beef Checkoff Program, which funds research and other activities, including promotion and consumer education, through fees on beef producers in the U.S. Since 2002, Mitloehner has received $5 million in research funding, with 5 percent of the total from agricultural commodities groups, such as beef producers.” The more recent release from the American Chemical Society did not include this detail, and neither did many news articles, with the exception of a blog post in the Guardian. The post made it clear that the author did not think Mithloehner was “in the pocket of Big Beef,” and that his criticisms of the FAO merited further investigation, but rightly criticized other outlets for overlooking an important detail of the story.)

So what about that 18 percent figure, then? Mitloehner is indeed skeptical about its accuracy, but he does not claim to be certain that it is wrong. He suspects that the FAO did not do a lifecycle analysis of the transportation industry because the data needed to do so is simply not available (which the FAO later confirmed). Without that information, Mitloehner argues, a comprehensive analysis is difficult.