Look I get it. The New York Times (NYT) does not like GMOs, industrial agriculture, factory farming or meat consumption. But I question the decision of such an influential media source to feature TWO front page articles detailing agriculture industry funding of agricultural scientists, Prof. Kevin Folta in 2015 and in 2022 Prof. Frank Mitloehner, who work doing public outreach in these fields. With the implication that they are “on the take” and promoting misinformation as a result of this funding. But what the NYT failed to show in these stories was that either of these public sector scientists, whose reputations the NYT has forever brought into question, ever made statements that were unsupported by peer-reviewed literature. There is a term for when someone attacks the character, motive, or some other attribute of the person making an argument, rather than the argument itself; it is called an “ad hominem” attack.

The most recent article featured one of my departmental colleagues at UC Davis, Professor Frank Mitloehner. The title of the article “He’s an Outspoken Defender of Meat. Industry Funds His Research, Files Show” was a little confusing, as it seemed to be suggesting the source of Professor Mitloehner’ s research funding was what was concerning, but in fact most of the article was about communication and outreach done by the Clarity and Leadership for Environmental Awareness and Research (CLEAR) Center at UC Davis, which receives almost all its funding from industry donations. Something that Professor Mitloehner has been very open about as detailed in his blog post, and on the CLEAR website. Prof. Mitloehner provides his response to the NYT article and accompanying Greenpeace hit piece here. The irony of Greenpeace, which itself has shamelessly ignored the scientific consensus  on the safety of GMOS and has engaged in ‘Tobacco-style’ PR on this topic for 30 years, accusing  Prof. Mitloehner of being  “a sock puppet” is projection at its finest.

The evidence that the NYT article provides to suggest that these communications are slanted is a statement by Matthew Hayek, an assistant professor in environmental studies at New York University. He states “Almost everything that I’ve seen from Prof. Mitloehner’s communications has downplayed every impact of livestock,” he said. “His communications are discordant from the scientific consensus, and the evidence that he has brought to bear against that consensus has not been, in my eyes, sufficient to challenge it.”

I am not sure exactly which specific scientific consensus Prof. Mitloehner’s communications are discordant from, but in presentations I have not heard Dr. Mitloehner make a statement that was not supported by peer-reviewed papers. I have heard him clearly state on multiple occasions that livestock are responsible for 14.5% of global emissions, and that cows and other ruminants account for 4% of US greenhouse gases (GHG) in concordance with the scientific consensus.

I am no GHG expert, but what really seems to be at the heart of people’s “beef” with Prof. Mitloehner’s communications is whether methane (CH4), as a short lived GHG, should be treated differently to CO2 which is a long-lived GHG in predictions of global warming impacts. This particularly impacts ruminants whose rumen-dwelling methanogenic bacteria produce (CH4) when breaking down otherwise indigestible cellulose. This is discussed on the CLEAR site.

This is actually NOT a settled science.  The commonly utilized ‘carbon footprint’ impact assessment makes use of the GWP100 metric, i.e., the global warming potential over a 100-year time horizon, while standardizing the atmospheric effects of all GHG to CO2-equivalents (CO 2-eq). It is typically claimed under GWP100 that methane (CH4) is, as a greenhouse gas, 28 times more potent than CO2. GWP100 became the standard metric more than 30 years ago when it was selected for in the Kyoto protocol. It has had a history of critiques in relation to characterizing the climate impacts of CH4 (Pierrehumbert, 2014). The authors of the Intergovernmental Panel on Climate Change Fifth Assessment Report themselves state that the GWP100 climate metric should not be considered to have any special significance.

A newer metric, GWP*, was developed by researchers at the Environmental Change Institute, School of Geography and the Environment, University of Oxford (Allen et al., 2018, Cain et al., 2019). These scientists argue that this metric more aptly represent how CH4 emissions translate into temperature outcomes at various points in time, by treating CH4 as a flow gas rather than a stock gas like CO2. This metric was not developed by the livestock industry. The New York Times article includes a quote “the use of that method [GWP*] by an industry “as a way of justifying high current emissions is very inappropriate.” However,  this metric is not necessarily “livestock friendly” under all conditions (Costa et al., 2021). In fact if livestock populations are increasing, the global warming impacts when using GWP* are higher than using the GWP100 metric. And Professor Mitloehner is not alone in suggesting that “expressing CH4 emissions as ‘CO2-equivalent’ emissions based on the GWP100 could misdirect attention from the need to reduce global net CO2 emissions to zero as quickly as possible” (Reisinger et al., 2021). Some have further argued that avoiding animal-sourced foods based on the GWP100 metric may result in trading a short-term climate benefit from reducing short-lived CH4 emissions, with a longer-term problem of increased CO2 and N2O emissions, making climate stabilization even more difficult.

Even the most recent IPCC technical report (2021; doi:10.1017/9781009157896.002) includes discussion of the GWP* metric

“New emissions metric approaches, such as GWP* and Combined GTP (CGTP), relate changes in the emissions rate of short-lived greenhouse gases to equivalent cumulative emissions of CO2 (CO2-e). Global surface temperature response from aggregated emissions of short-lived greenhouse gases over time is determined by multiplying these cumulative CO2-e by TCRE (see Section TS.3.2.1). When GHGs are aggregated using standard metrics such as GWP or GTP, cumulative CO2-e emissions are not necessarily proportional to future global surface temperature outcomes (high confidence).”

The best way to do environmental assessments of the livestock sector is not a settled science. All-too frequently assessments are stated in simplistic terms, making use of a myopic selection of metrics, and overlooking underlying heterogeneity and complexities. If the New York Times has problems with the way that Prof. Mitloehner and the CLEAR center communicate these topics then they should provide their science-based arguments as to why the approach he is using is incorrect. Not malign his reputation by implying he is putting out information that is “discordant from the scientific consensus” with no further elaboration as to what exactly he said that was incorrect, or which specific consensus his information is discordant from. Nor discredit his work solely because of the industry funding he clearly discloses. Because that is how science works, not through “ad hominem” attacks.