Their paper, recently published in Environmental Research Letters, found that the global food system was responsible for 16 billion metric tons of greenhouse gas emissions in 2018, or a third of all global emissions that year. This is a sharp contrast to the more narrowly defined agriculture sector of the IPCC’s categories for greenhouse gas inventories, which accounted for 5.3 billion metric tons in 2018, or just a tenth of the total.
To be clear, this analysis doesn’t add to the total global greenhouse gas emissions. Rather, it simply collects all the food-related emissions in one place in an attempt to accurately illustrate the true size of food’s carbon footprint. And it reinforces a 2020 research paper that found avoiding catastrophic climate change will be impossible without radically cutting emissions from the global food sector.
The new analysis accounts for those emissions that the IPCC allocates to non-agricultural categories, including carbon dioxide from pre-production, like manufacturing fertilizer and farm equipment, and post-production emissions, such as food waste disposal, refrigeration, packaging, and transportation. It also includes as food-related emissions the conversion of natural ecosystems to agricultural land, which at nearly 3 billion metrics tons per year are the largest single source of greenhouse gas emissions in their analysis.The Food System’s Carbon Footprint Has Been Vastly Underestimated | Civil Eats