Feeding a world population of 10 billion people by 2050 within planetary limits is possible if we change the way we eat and produce food, new research shows. A global shift towards healthy and more plant-based diets, halving food loss and waste, and improving farming practices are measures required to reduce the environmental impacts of the food system, says the study published in October in the journal Nature. “Greening the food sector or eating up our planet: this is what is on the menu today,” explains co-author Johan Rockström. The international research team quantified how food production and consumption affects the planetary boundaries that describe a safe operating space for humanity beyond which Earth’s vital systems could become unstable. „The food system is a major driver of climate change, changes in land use, depletion of freshwater resources, and pollution of aquatic and terrestrial ecosystems through excessive nitrogen and phosphorus inputs,” reads the abstract of the study. The authors show that between 2010 and 2050, as a result of changes in population and income levels, accompanied by a rise of diets high in fats, sugars and meat, the environmental effects of the food system could increase by 50–90%, reaching levels that are beyond the planetary limits.

The study combined detailed environmental accounts with a model of the global food system that tracks the production and consumption of food across the world. With this model, the researchers analysed several options that could keep the food system within environmental limits. “To keep food production within planetary boundaries, we can do three things: eat healthier more plant-based diets, systematically reduce food loss and waste, and improve agricultural technologies like for instance tillage or fertilizer recycling,” said Rockström. Adopting more plant-based “flexitarian” diets globally could reduce greenhouse gas emissions by more than half, and also reduce other environmental impacts, such as fertilizer application and the use of cropland and freshwater, by a tenth to a quarter. “When it comes to diets, comprehensive policy and business approaches are essential to make dietary changes towards healthy and more plant-based diets possible and attractive for a large number of people,” said the lead author, Marco Springmann from the University of Oxford. “Important aspects include school and workplace programmes, economic incentives and labelling, and aligning national dietary guidelines with the current scientific evidence on healthy eating and the environmental impacts of our diet,” he added.

In addition to dietary changes, improving management practices and technologies in agriculture is required to limit pressures on agricultural land, freshwater extraction, and fertilizer use. “Improving farming technologies and management practices will require increasing investment in public infrastructure, the right incentive schemes for farmers, including support mechanisms to adopt best available practices, and better regulation, for example of fertilizer use and water quality,” said Line Gordon, another study author. Finally, halving food loss and waste is needed for keeping the food system within environmental limits. Halving food loss and waste could, if globally achieved, reduce environmental impacts by up to 16%. “Tackling food loss and waste will require measures across the entire food chain, from storage, and transport, over food packaging and labelling to changes in legislation and business behaviour that promote zero-waste supply chains,” said co-author Fabrice de Clerck. “No single solution is enough to avoid transgressing planetary boundaries. But when they are implemented together, our research indicates it may be possible to feed the growing population sustainably,” said Dr Springmann. (ab)