How much do dairy cows contribute to global warming?

Article 2 min

Answering this question requires a nuanced understanding of agricultural emissions. In this article, Dr Frank Mitloehner of UC Davis clarifies some common FAQs.

By DFC - PLC, Communications Team


  • Does raising cattle increase global warming or not?
  • How do you see the future of cattle farming?

Patrick Dupuis is Deputy Editor at the magazine Coopérateur. The full version of the article below appeared in the October 2019 edition of the Coopérateur. Here is an excerpt.


Coopérateur : Why is it so difficult to obtain data that reflects the real contribution of livestock to global warming?


FM : It's because we are facing different levels of complexity. One of these is associated with the scale used. Some like to describe the raising of livestock in agriculture in a particularly negative way and frequently use global data to characterize the regional impact of livestock on the climate. Globally, agriculture produces 14.5% of the greenhouse gases (GHGs) emitted by human activity. This is the data conveyed by those who support the production of plant-based burgers and milk and who suggest that we no longer consume these products when they come from livestock production. This data is confusing. In the United States, Canada and Europe, agriculture as a whole accounts for 9% of emissions. Animal production is responsible for 3.9% of emissions, and the rest comes from crop production. This is already a first level of confusion. The promoters of "meatless Monday" or your new food guide rely on global data to promote their ideas.


What is the main source of greenhouse gas emissions?

The elephant in the room, at least in our country, is not the raising of livestock but the consumption of fossil fuels. According to the US Environmental Protection Agency, the main source of greenhouse gases is the combustion of fossil fuels. Without a doubt. Transportation, electric power generation, and industry account for nearly 80% of greenhouse gas emissions.


So, does raising cattle increase global warming or not?

As long as you do not add animals to your herds, the answer is no. If the herds remain the same size, or if you reduce their size, the methane emissions are in balance with their degradation, that is to say the amount of methane produced is equal to the amount degraded. So we are not adding new quantities of methane to the atmosphere, and we are not contributing to ADDITIONAL global warming. It should also be mentioned that the increase in the efficiency of livestock production now makes it possible to produce the same quantity of milk and meat with fewer animals.


What do you think of the trend to not eat meat?

This trend is endorsed by only a small proportion of the population, barely 2%. More than 98% of the population in Canada and the United States consumes meat.


How do you see the future of cattle farming?

Knowing that the land we have to produce food is limited, we must know how to take advantage of marginal land that is not conducive to crop production. Beef cattle have the ability to consume and digest the cellulose in the plants that grow on these lands to produce meat. I'm 50 years old. When I was young, the planet had 3 billion people. We are 7.6 billion today and we will be 9.5 billion in 2050. That's three times more. But the resources to feed us will not triple, which is why we must absolutely use all the resources available to us to produce our food. There are no other options available.


This article is courtesy of Patrick Dupuis. Patrick is Deputy Editor at the magazine Coopérateur. Agronomist graduated from McGill University, he also studied sustainable development. He works at the Coopérateur for over twenty years.

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