Frank Mitloehner, professor and air quality specialist at UC Davis, University of California, asks Greenpeace for answers via Twitter about his recent claims about emissions of farms higher than cars, according to the NGO.

“Comparing apples with oranges” (or pears with bananas, as we said a few days ago) does not lead anywhere, indeed it creates confusion. This is the case with data from Greenpeace’s recent ‘Farming for failure’ report, which attributes to European meat production more greenhouse gas emissions than those of the entire circulation of vehicles. Frank Mitloehner, professor and air quality specialist at UC Davis’ Department of Animal Sciences, University of California, values the truth. So he asks the environmental association for answers on Twitter. We anticipate that answers will come in a small part.

It all starts with an article in The Guardian, a leading British newspaper whose interests of “Plant-Based” food producers have recently been revealed, echoing Greenpeace’s report on European livestock accused of fuelling the climate emergency, entitled “Farming for failure“. In short, intensive farming would account for 17% of total greenhouse gas emissions in the EU, higher than that of all cars and vans, responsible for 14%.

False. Professor Mitloehner in the 17 tweets written for answers, points out that the report relies on data referred to as scientific, but that they are actually not. In fact, in the study, the amount of CO₂ emissions attributed to livestock is linked to the Life-Cycle Assessment (LCA) that considers the entire environmental impact of a product, at all stages. In this case, the data combines the enteric fermentation of ruminants, the manure left on the pastures, the manure management, the manure applied to the soil, the activities in the farm, the processing, the transport, and packaging: in short it counts all direct and indirect emissions.

The problem arises because Greenpeace did not refer to the life cycle analysis to calculate the emissions of the automotive industry, but only counted the direct ones, so having used “double standards” got results that are incorrect to compare scientifically. “Globally, according to the IPCC (Intergovernmental Panel on Climate Change), agriculture –”Farming for failure” states – accounts for about a quarter of total anthropogenic emissions (23% on average), with a growing trend, while it is estimated that the agri-food system overall contributes 21% – 37%. […] Global livestock emissions are comparable to those of the entire transport sector (14.5% of total greenhouse gas emissions).”

“Greenpeace used direct emissions only for cars, completely omitting the indirect environmental impacts of vehicles, such as road construction, metal production, fuel use, and so on. NGO did not use the same methodology to compare the two sectors, and on the calculation of environmental impact it did not take into account the mitigation and sustainability practices applied by European farmers since 2004,” Mitloehner writes on the social network.

Finally, the UC Davis lecturer, after reporting graphs from a European Environment Agency (EEA) study comparing livestock and transport emissions, responsible for 6% and 20% of greenhouse gases respectively, points out that Greenpeace used CO₂ equivalent in the calculations, considering different greenhouse gas emissions which have different climate-warming effects. For example, a ton of methane has a climate-warming potential 28 times higher than CO₂, but it does not remain in the atmosphere for a thousand years like CO₂, but only for a dozen.

On the other side, Greenpeace simply responded, also via Twitter, that a life cycle analysis was made to measure the impact of livestock farms, but that a comparison of the life cycle assessments of the different sectors was not the objective of the report. If this is science…