Sustainable diets could help limit global warming to 1.5°C – report

A global transition to healthy, more sustainable diets could considerably reduce greenhouse gas emissions and help limit global warming to the Paris Agreement goal of 1.5°C, researchers at the Potsdam Institute for Climate Impact Research (PIK) have said. In an article published in Science Advances, they detail how the resulting emissions reduction would increase the available carbon budget compatible with limiting global warming to 1.5°C for other sectors, making it possible to achieve the same climate outcome with less carbon dioxide removal and less stringent CO2 emissions reductions in the energy system. This would also reduce emission prices, energy prices and food expenditures.

“We find that a more sustainable, flexitarian diet increases the feasibility of the Paris Agreement climate goals in different ways,” said Florian Humpenöder, PIK scientist and co-lead author of the study. “The reduction of greenhouse gas emissions related to dietary shifts, especially methane from ruminant animals raised for their meat and milk, would allow us to extend our current global CO2 budget of 500 gigatons by 125 gigatons and still stay within the limits of 1.5°C with a 50 percent chance,” he added. Placing a price on greenhouse gas emissions in the energy and land system is “an important policy instrument to stay within the limits of 1.5°C warming”, the report noted. Compared to continued dietary trends, a more sustainable diet not only reduces impacts from food production within the land system, such as deforestation and nitrogen losses. It also reduces emissions from the land system to such an extent that it cuts economy-wide 1.5°C-compatible emissions prices in 2050 by 43 percent,” adds Alexander Popp, co-lead author and head of the PIK’s land-use management working group. "Moreover, healthy diets would also reduce our dependency on carbon dioxide removal in 2050 by 39 percent." 

Germany is aiming to reduce its agricultural emissions, which make up about 7 percent of total greenhouse gas emissions, in order to achieve climate neutrality by 2045 and comply with the Paris Agreement.