To combat climate change, the global food system needs an overhaul – not only are plant-based diets accompanied by a lower incidence of noncommunicable disease and other health benefits, but they are also better for the planet. So, how do our diets impact climate change? A lot, it seems.
The global food system accounts for about 37 per cent of all greenhouse gas emissions and nearly one-quarter of the world’s total emissions. Reducing food loss and waste as well as transitioning to sustainable diets could have a significant impact on carbon dioxide (CO2) emissions, according to a report released from the United Nations, World Wildlife Fund, and Climate Focus in August.
Dr Charlotte Streck, co-founder and director of Climate Focus said: “Food systems are a neglected mitigation opportunity and there is rarely any mitigation opportunity with so many sustainable benefits”.
The researchers identified sixteen ways in which policymakers can increase sustainability throughout the food production chain, including agricultural emissions, reducing food waste, and shifting to healthier, more sustainable diets, which they found may contribute up 20 per cent of the mitigation effort required to keep global temperature rise below the 1.5 degrees Celcius target by 2050.
Shifting to plant-based diets that are high in coarse grains, fruits, vegetables, nuts and seeds, while limiting meat intake to around 60 grams per person per day could reduce agricultural emissions by up to eight gigatons of carbon each year, thereby helping to mitigate climate change.
They also suggest that existing agriculture and ranching operations could become more sustainable by improving drainage systems in flood-prone areas and shifting away from monocultures.
Another study published last month in Nature Sustainability found that a widespread dietary shift from meat to plant-based foods over the next few decades could remove as much as 16 years of global fossil-fuel CO2 emissions – which could essentially double the Earth’s rapidly diminishing carbon budget (1).
Plant-based proteins, like nuts, beans, and lentils, use only a portion of the land required to produce dairy and meat – while still providing essential nutrients. A shift to plant sources of protein would free up land that could be used to support beneficial ecosystems, such as native forests that absorb carbon dioxide.
However, raising animals is critical in some developing economies. To address this, the authors suggest locally tailored strategies, for example, targeting regions where restoring ecosystems and halting ongoing deforestation would have the largest carbon benefits.
“We can think of shifting our eating habits toward land-friendly diets as a supplement to shifting energy, rather than a substitute. Restoring native forests could buy some much-needed time for countries to transition their energy grids to renewable, fossil-free infrastructure”, said lead author of the Nature Sustainability paper, Dr Matthew Hayek, an assistant professor in the Department of Environmental Studies at New York University. The authors also pinpointed 7 million square kilometres of land where forests would be wet enough to regrow and thrive naturally.
The idea of restoring natural forests echos recent calls from scientists to plant a billion trees to mitigate climate change. Indeed, scientists say the best approach is to allow trees to regenerate in areas that were formerly forests.
Beyond environmental benefits, the current pandemic clearly highlights the potential risks of burgeoning wildlife trade and animal consumption, which increase the risk of disease outbreaks, like COVID-19.
(1) Hayek, M.N. et al. The carbon opportunity cost of animal-sourced food production on land. Nature Sustaibability (2020). DOI: 10.1038/s41893-020-00603-4