Without Changes, Global Food Systems May Drive World Beyond Climate Targets, Says Study
Production of meat, dairy and rice are the leading sources of food-related emissions. Improved management practices and changes in diet could go a long way to addressing the issues.
A new study by climate scientists sheds light on the significant role food systems will play in future global warming, and what can be done about it. The research, published in the journal Nature Climate Change, finds that food production, distribution and consumption under existing practices could add around 1 degree C to planetary warming by 2100—and, in turn, risk exceeding the internationally agreed-upon 1.5 C temperature target.
The study, which is based on extensive global datasets, models and data from more than 100 studies, shows that more than half of this warming, about 55 percent, could be avoided by changes in agricultural production practices, decarbonization of the energy used to produce food, shifts in consumer food choices, and reductions of food waste. The top agricultural sources of greenhouse gases identified by the study: production of meat, dairy and rice.“This research highlights the urgent need for action to reduce emissions from food systems,” said lead author Catherine Ivanovich, a Ph.D. candidate at the Columbia Climate School’s Lamont-Doherty Earth Observatory.
“By understanding which food items and greenhouse gases contribute most to future warming, we can address these emissions with targeted strategies which both reduce future climate change and promote food security.”Of the warming expected by the end of the century from business-as-usual food systems, methane emissions, mostly from livestock burps and manure, rice paddies and decomposing food waste, account for nearly 60 percent. Carbon dioxide, such as that generated from fuel used for farm equipment and food transportation, and nitrous oxide, from excess synthetic fertilizer and ruminant manure on rangelands, are each responsible for about 20 percent.
The study quantified the mitigation potential of four solutions. The researchers said improvements to production practices and adoption of technologies that decrease methane and nitrous oxide emissions from livestock could provide 25 percent of the reductions possible by the end of the century. These changes could come from scaling up innovative solutions to methane emitted from the guts of ruminant animals, and the widespread use of better manure-management practices. The result could be decreasing emissions from ruminant meat, dairy and non-ruminant meat by 35 percent, 30 percent and 10 percent, respectively, by 2100.
The researchers say decarbonizing the energy sources used to produce, process and transport food by 2050, in line with international net zero goals, would decrease expected warming from global food systems by 17 percent by 2100.
- (Grafik: Ivanovich et al./Nature Climate Change)
If health-focused recommendations were adopted globally, the world could avoid 21 percent of predicted food system-driven warming. However, the researchers note that because dietary choices are extremely complex, often determined by cultural traditions and food access, it is difficult to assess how much of this mitigation potential is realistic or ethical to achieve.
Cutting consumer-level food waste in half by 2100 would provide an additional 5 percent reduction in anticipated warming, the study says. However, due to data limitations, the study could not assess food waste incurred during production and transportation, which could be another significant opportunity for mitigation.
“The findings of our study offer a set of solutions to policymakers, industry and the public,” said coauthor Ilissa Ocko, a senior climate scientist at the Environmental Defense Fund. “We can provide food for a growing population, support the farmers, pastoralists and rural communities around the world, and still make critical advances toward a more sustainable, equitable food system. Solutions will look different around the world, but we should work together with the shared goal of stabilizing the climate.”
Columbia University in the City of New York 2023 | By Columbia Climate School | Adapted from a press release by the Environmental Defense Fund.