The global food system accounted for 18 billion tonnes of greenhouse gases (GHG) in 2015, accounting for 34% of the total amount emitted by human activities that year, according to a new report by the United Nations’ Food and Agriculture Organization (FAO).

While the share of GHG attributable to the global food system has technically declined from a high of 44% in 1990, emissions from the sector have still seen a significant increase over the years. In other words, emissions from other sectors, particularly energy use, have increased at a far greater rate. 

At the same time, per capita emissions from the food sector — meaning how much emissions each person is responsible for — has declined from 3 tons of emissions per person in 1990 to 2.4 tons in 2015.

This shows that advances in technology and better management of food systems can reduce overall environmental impact, the authors of the FAO report explain. They released a database called EDGAR-FOOD to help policymakers build on past gains. 

The report notes that industrialized countries accounted for 27% of GHG from the food sector in 2015, while developing countries, including China, accounted for 73% of these emissions. 

The top emitting economies are China, Indonesia, the United States, Brazil, the European Union, and India, according to the report.

The global food system is sprawling, covering everything from industrial farms and cattle-rearing operations to the factories that process foods and the transportation infrastructure that carries products to grocery stores and food markets worldwide. It also includes waste management of food.

The report says that the initial production of food — agriculture, aquaculture, raising animals — accounts for the largest portion of greenhouse gas emissions, at 39%. Land-use activities — converting wild land for agricultural use — accounts for 32% of emissions. The vast majority of these emissions come from “carbon losses from deforestation and from degradation of organic soils, including peatlands,” meaning the CO2 that these habitats stored is released into the atmosphere.

The rest of food sector emissions come from the distribution, processing, consumption, and waste management of food.

Because the majority of global food-based emissions come not from burning fossil fuels but from emissions from animals, degraded land, and other industrial processes, world leaders will have to develop energy-reduction strategies that are specific to the food sector, the report says. 

This can be done in a number of ways. Most importantly, conserving the natural world — peatlands, forests, and grasslands — will prevent further emissions from being released. Regenerating soil worldwide can improve the ability of smallholder farmers to grow food, while also creating carbon sinks. Reducing the production of meat can limit methane emissions, deforestation, and water use. And building more efficient food delivery networks will make sure food reaches people rather than landfills. 

By 2050, countries will have to grow more food on less land, according to the World Resources Institute.

Transforming the global food system will be challenging — but solutions are available and the FAO’s new database can help guide policymakers.