Study on climate protection: More forest -- less meat

According to the Paris Agreement, global temperature increase must be limited to well below 2°C, if possible, to 1.5°C. Land-based mitigation measures, especially afforestation, reforestation, and avoided deforestation, can help reach this goal. Trees absorb CO₂ greenhouse gas from the atmosphere to produce biomass and, thus, fight against global warming. The expansion of forests, however, competes with land for agriculture not only regionally, but also globally. The more so as global population growth and change of dietary habits will cause the worldwide demand for food and in particular for meat to increase.

With the help of model simulations, researchers of the Atmospheric Environmental Research Division of KIT's Institute of Meteorology and Climate Research (IMK-IFU), i.e. KIT's Campus Alpine in Garmisch-Partenkirchen, the University of Edinburgh, Cranfield University / UK, and the TIAMASG Foundation in Bucharest recently studied the conditions under which forests in Europe can bind sufficient carbon. For their study published in Environmental Research Letters, the scientists used an integrated model developed within the EU project IMPRESSIONS (Impacts and risks from high-end scenarios: strategies for innovative solutions). By using this interactive, web-based platform, impacts of climate change, damage potentials, and adaptation strategies can be investigated. The so-called integrated assessment platform (IAP) comprises interconnected meta-models for urban development, water resources, floods, forest, and agriculture, as well as biodiversity and visualizes relationships between climatic and socioeconomic factors.

"We compared various scenarios with variable demands for meat, cultivations of energy plants, irrigation efficiencies, and harvest yield increases," says Dr. Heera Lee of IMK-IFU, the first author of the study. Of a total of 972 simulations for the 2050s, 351 reach the minimum values for both forest area and food supply targets. This means that the forest area must expand by at least 23 per cent compared to 2010 to reach the Paris climate goal and a food energy supply of at least 2800 kcal per person and day. Of these successful simulations, 42 do not require any change of dietary habits, but an increase in harvest yield by at least 30 per cent in Europe. Six simulations require replacement of ruminant meat by other meat, 215 require reduced meat consumption by 25 to 75 per cent, 88 no meat consumption at all, with the harvest yields having to be increased by at least 15 per cent in both cases. "Our study reveals that sufficient expansion of forest areas for climate protection and secure food supply require a transformation of the food system on both the supply and the demand side, with partial or total meat avoidance certainly being a great challenge in practice," Dr. Heera Lee says. "It is important not to increase food imports to Europe in order to prevent a shift of food production and deforestation in other regions of the world."