Shifts in diet, food loss and waste, and production efficiencies can reduce food system emissions drastically, reducing food system greenhouse gas emissions by over 50%. But these shifts cannot result in a net zero food system. In order to meet the net zero target additional action is needed.
My colleagues and I analysed the potential impact of tech-based approaches on climate outcomes. These include things like feed additives to livestock systems, biochar amendments in production systems, and restoration of abandoned agricultural lands into natural ecosystems.
We used a global food system model to explore how consumer choices, climate-smart technologies and reductions in food waste would each contribute to achieving net negative emissions by 2050.
By our estimates, in a world of 10 billion people, a complete food system transformation could remove the equivalent of up to 33 gigatons of carbon dioxide each year. The greatest benefits would come from a shift toward a plant-based diet and the introduction of technologies that reduce emissions from food production or increase rates of carbon sequestration in agricultural landscapes.
For the technologies examined, the largest estimated benefits came from restoration of abandoned agricultural lands to natural ecosystems, seaweed farming, and biochar amendments. Other technologies, such as feed additives to reduce methane in ruminant systems, anaerobic digestion and more sustainable trawling in fisheries systems, would bring smaller estimated climate benefits.
Our analyses, published in the journal PLOS Climate, are based on evidence from field trials, and we were not able to measure whether they would scale to the full system, whether this can actually happen remains a key unanswered question.
We did not analyse the economic, logistical, social, or other implications of these technologies. These are very important questions, as they are major barriers to implementing the technologies we investigated in ways that benefit both people and planet.
Diet swaps to healthier diets, and other non-tech based changes to the food system such as reductions in food loss and waste, remain a key goal. They bring benefits to multiple aspects of the environment, and also to health and nutrition, in ways that technologies may not.