Sustainable diets may transform global food systems by 2050

There is a clear need to shift towards healthier and more sustainable food systems. According to the 2025 EAT-Lancet Commission Report, the global adoption of a flexitarian Planetary Health Diet could prevent around 15 million premature adult deaths per year. Today, food systems account for around one third of global anthropogenic greenhouse gas emissions, and are the main driver of five planetary boundary transgressions. At the same time, one third of all food is lost or wasted, while half of the world's habitable land is used for agriculture – mostly for livestock and animal feed.

To explore the potential impacts of a food system transformation, researchers used ten global food system models to compare a "business-as-usual" scenario until 2050 with a "transformation scenario" characterised by healthy diets, improved agricultural productivity, and halved food waste.

Hermann Lotze-Campen, PIK research department head and co-author, said: "Our study shows that continuing on the current path is the more expensive option. Providing healthy diets for a growing global population by 2050 would maintain the overall value of agricultural production near 2020 levels, while simultaneously reducing environmental and health costs compared to business-as-usual." 

Transformation would reduce global agricultural land use by 9 percent compared to business as usual

In all models, the business-as-usual scenario leads to increased animal numbers, larger harvested areas, higher production levels and greater environmental impacts like greenhouse gas emissions and nitrogen fertilisation. Under the transformation scenario, however, a larger share of agricultural products would be used directly for food, and less for animal feed. The transformation scenario also projects less meat, dairy, cereal and sugar crop production, reduced animal numbers, and lower pressure on land resources, lower production costs and producer prices in these sectors relative to business-as-usual.

Lead author Matt Gibson, Research Fellow at the London School of Hygiene and Tropical Medicine, who coordinated the study while at Cornell University, said: "Across all the models we employed, a transformation could reduce global agricultural land use by 9 percent and livestock production value by 60 percent by 2050, relative to business as usual, with total agricultural output reduced by 17 percent, mostly from livestock changes. These reductions are partly offset by growth in other sectors, with the economic production value of vegetables, fruits, nuts and legumes projected to increase by a median of 23 percent." 

Net CO₂ emissions from agriculture-related land-use change would decline by 76 percent

These production trajectories would have far-reaching implications for the political economy of global food systems. While the adverse effects are often concentrated, for example in livestock-oriented rural economies, the benefits for public health and the environment are more widely distributed. In fact, net CO₂ emissions from agriculture-related land-use change would decline by 76 percent by 2050 under a transformation scenario, compared to business as usual, while direct non-CO₂ greenhouse gas emissions from agricultural production would fall by one third.

"While the environmental and health opportunities are huge, managing structural challenges within the agricultural sector will require coherent food and agriculture policies and inclusive stakeholder dialogues," said PIK scientist Felicitas Beier, also co-author of the study.

The authors conclude that the scale of change implied by a food system transformation calls for commensurate policy ambition, and that bold decisions in the present can help support those who could be adversely affected by the transition while maximising the benefits of a transformed food system.