Optimising Food Production and Carbon Storage

Model simulations show how a spatial reconfiguration of land use can increase food production while simultaneously storing more carbon

A radical reconfiguration of historically evolved systems of land use would make it possible in principle to double food production, save water, and increase carbon storage at the same time. This was the result of a study conducted by geoinformation scientist Sven Lautenbach of Heidelberg University and the Heidelberg Institute for Geoinformation Technology (HeiGIT) along with two researchers from the Karlsruhe Institute of Technology (KIT). The analyses of the biophysical yield potential are based on a dynamic vegetation model combined with an optimisation algorithm that made it possible to simulate alternative patterns of global land use.

The way that people use the Earth’s surface for food production has changed dramatically over the last centuries. The need for food grows with the increase in the world’s population; at the same time food can now be transported around the globe very quickly. The historically evolved systems of food production, however, do not reflect the biophysical potential of the Earth’s ecosystems. As Prof. Lautenbach stresses, food is not produced where it would be most efficient in terms of land and water use as well as CO2 emissions. Instead, report the Heidelberg researcher and his Karlsruhe colleagues, forests continue to be cleared for crops and grazing, and fields in dry areas irrigated - actions that negatively affect water availability and carbon storage.

The dynamic vegetation model and the optimisation algorithm make it possible to study alternative patterns of global land use with a view towards optimisation and efficiency. In a variety of scenarios, fields, pastures and natural vegetation were relocated to especially efficient land use areas and croplands restricted to areas not requiring intensive irrigation. The modelling takes into account two different climate change scenarios - for the near future from 2033 to 2042 and for the period from 2090 to 2099. 

One result of the simulations: spatial restructuring alone could increase food production by an average of 83 percent while simultaneously raising available water - after deducting the water demand of natural vegetation and agriculture - by eight percent and CO2 storage by three percent. The increases would be considerably higher if one of the three target figures took precedence over the others. The research results show that regional practice deviates quite a bit from the theoretically achievable optimum and massive land use changes would be needed to make better use of biophysical potential, thus equally increasing the overall yields of food, water, and carbon storage. 

"Although such major land use changes appear to be unrealistic, we should be aware of the fact that climate change will be associated with big changes of cultivation areas anyway," states Prof. Lautenbach, who teaches and conducts research at Heidelberg University’s Institute of Geography. "We should not let these changes happen, but try to manage them taking into account the biophysical potential."

The results were published in the "Proceedings of the National Academy of Sciences". The research was funded within the framework of the "Operational Potential of Ecosystem Research Applications" project of the European Commission and the Federal Ministry of Education and Research through the Helmholtz Association and its research programme "The Atmosphere in Global Change".

A. D. Bayer, S. Lautenbach, A. Arneth: Benefits and trade-offs of optimizing global land use for food, water, and carbon. PNAS (9 October 2023).