We Have to Change What We Eat to Stop the Climate Crisis

What we eat, how much we eat, and how much we waste puts us over 1.5 degrees.

Tractor spraying in a field.

Peter Cade / Getty Images

Food production is responsible for about 30% of the world's greenhouse gas emissions. It's enough that new research from the University of Oxford shows that if nothing is done about it, the Paris Agreement goal of keeping the temperature rise below 2°C will not be achieved even if fossil fuel use stopped immediately. Emissions from food alone will be enough to miss the target.

The study, "Global food system emissions could preclude achieving the 1.5° and 2°C climate change targets," notes that the emissions come from multiple sources, including deforestation, production of fertilizers, methane from sheep, cows, and goats, manure, methane from rice production and the fossil fuels used in food production and the supply chains. The authors write:

"Our analysis suggests that reducing GHG emissions from the global food system will likely be essential to meeting the 1.5° or 2°C target. Our estimate of cumulative business-as-usual food system emissions from 2020 to2100 is 1356 Gt CO2. As such, even if all non–food system GHG emissions were immediately stopped and were net-zero from 2020 to 2100, emissions from the food system alone would likely exceed the 1.5°C emissions limit between 2051 and 2063.

And they don't even include the emissions from transportation, packaging, retail and preparation, suggesting that it's only 17% of emissions; they consider that a "minor fraction."

Our World In Data Emissions from food production

CC Our World In Data

The study proposes a multi-pronged approach for "extensive and unprecedented changes to the global food system."

  • Adoption of a plant-rich diet such as a Mediterranean diet or the EAT-Lancet diet (also called the Planetary Health Diet, covered on Treehugger here) containing "moderate amounts of dairy, eggs and meat";
  • Reducing the amount that we eat, getting our caloric consumption down to healthy levels;
  • Improving yields through crop genetics and agronomic practices;
  • Reducing food waste and loss by 50%;
  • Reducing use of nitrogen fertilizers.

Katherine Martinko reviewed another study of the EAT-Lancet diet and noted that switching to it would require changes in diets around the world, but would have multiple benefits. She noted:

"The changes do not affect just meat-loving North Americans and Europeans. It requires East Asians to reduce fish and Africans to reduce starchy vegetable consumption. These changes, the report authors suggest, would save 11 million lives annually while minimizing GHG emissions, slowing species extinction, stopping the expansion of farmland, and preserving water."

However, none of the proposed options on their own are enough, but even 50% adoption of all five could reduce emissions by 63%, and going 100% could actually have negative emissions.

Many have focused on red meat as being the real villain, but this study is not so doctrinaire. Treehugger reached out to the lead author of the paper, Dr. Michael Clark, to ask why they did not recommend a vegetarian or vegan diet. He responded:

"You're correct that we did not include a vegetarian or vegan diet, but I also wouldn't say that the EAT-Lancet diet is far more moderate than these. The EL diet allows for ~14g red meat/day, with slightly more poultry and fish. Compared to current diets in many countries, meeting the EL diet would still require a very very large change from current dietary choices. From a psychological perspective, communicating 'eat less meat' seems to be a more effective way to get people to shift their dietary habits than is 'eat no meat.'"

The researchers note that there are other benefits that come from these proposed changes, including decreased nutrient and water pollution, decreased land-use change, improved biodiversity, and "if dietary composition and caloric consumption are improved, reduced prevalence of obesity, diabetes, heart disease, and premature mortality." And we have to start now:

"Time is of the essence in addressing GHG emissions. Any delays will necessitate more ambitious and expeditious implementation of emissions reduction strategies if global temperature targets are to be met."

None of the five strategies seem particularly dire, but anyone watching the politics of fish in the UK or meat in the US will recognize the challenge. But as Martinko wrote, "What we eat has to be taken into consideration when talking about the planet's future."