big brown cow
© David George on Unsplash
Mistaken science is distracting us.

Cattle have been denigrated as a major cause of greenhouse gases (GHG) and, therefore, a cause of climate change. When I first heard this as a former farmer, I thought: That's preposterous! Do cows have more impact than fossil fuels? No way.

Big claims

So, I looked it up. Sure enough, a 2009 report from the WorldWatch Institute claims livestock accounts for 51% of GHG — more than industry, coal-burning electricity generation, and transportation combined. Whatever those guys smoke at WorldWatch, I'd like some for Friday night! That report is no longer available on the WorldWatch site. (Links go to a dead page. A reader sent me this one.) It's not hard to figure out why.

The original story emphasizing the GHG contribution of livestock came from the United Nations Food and Agriculture Organization (FAO). FAO published a study authored by Henning Steinfeld in 2006, which claimed that livestock produced 18% of global GHG and concluded that livestock was producing more GHG than the entire transportation sector. Although it is a mystery how WorldWatch inflated that to 51% three years later, the claim in the FAO study was eye-catching. Apparently, many eyes caught it, and then they read WorldWatch, too.

But there was a slight problem.

A mistake in the science

Frank M. Mitloehner, Professor of Animal Science and Air Quality Extension Specialist, University of California, Davis, reviewed the report and raised an issue with the carbon footprint comparison at the center of this conclusion. Here's what he wrote:
The problem was that FAO analysts used a comprehensive life-cycle assessment to study the climate impact of livestock but a different method when they analyzed transportation.

For livestock, they considered every factor associated with producing meat. This included emissions from fertilizer production, converting land from forests to pastures, growing feed, and direct emissions from animals (belching and manure) from birth to death.

However, when they looked at transportation's carbon footprint, they ignored impacts on the climate from manufacturing vehicle materials and parts, assembling vehicles, and maintaining roads, bridges, and airports. Instead, they only considered the exhaust emitted by finished cars, trucks, trains, and planes. As a result, the FAO's comparison of greenhouse gas emissions from livestock to those from transportation was greatly distorted.
The study author corrects his mistake

This oversight was pointed out by Professor Mitloehner, and Mr. Steinfeld, the original author of the FAO report, corrected this mistake. A subsequent article by him addresses the issue directly:
The comparison measures direct emissions from transport against both direct and indirect emissions from livestock. The Intergovernmental Panel on Climate Change (IPCC) identifies and monitors human activities responsible for climate change and reports direct emissions by sectors. The IPCC estimates that direct emissions from transport (road, air, rail, and maritime) account for 6.9 gigatons per year, about 14% of all emissions from human activities. These emissions mainly consist of carbon dioxide and nitrous oxide from fuel combustion. By comparison, direct emissions from livestock account for 2.3 gigatons of CO2 equivalent, or 5% of the total. They consist of methane and nitrous oxide from rumen digestion and manure management.
In other words, if you compare the same types of contributions to GHG, namely the direct emissions, transportation is 14%, and livestock is 5%. There is no data on the indirect emissions from transportation, so a direct comparison cannot be made.

The point is that livestock only accounts for a very small portion of greenhouse gas emissions. Science is a process of continuing to peel back layers of the onion, so to speak, until you get to the truth. Big claims derived from the science by ideologically-driven think tanks (like WorldWatch) must be regarded with some skepticism. Individual scientists must be examined for their links to industry and interested parties. Eventually, the truth comes out. But sometimes, as in this case, it comes out way too late, and the initial incorrect conclusions can taint public thinking for a long time.

Advocates distract from real climate solutions

The claim that cattle produce excessive greenhouse gases (GHG) was a mistake. Pro-vegan folks may not like to hear it, but going vegan will have a minimal impact as a climate change solution. Nonetheless, for years — and even today — climate advocates have been pouring energy into this mistaken priority because if they could get everyone to swear off beef, it would fix the problem. That conclusion, however, is pseudoscience, and it distracts us from the arguments and actions that will have a significant impact. The only real solution is to stop burning stuff, and for that to happen, we need better technology, new systems, and policies that encourage them.

Anthony Signorelli - You can find my newsletter Intertwine: Living Better in a Worsening World