study released Monday from Nature Food has shown how food production plays a major role in climate change. Global greenhouse gas emissions from animal-based foods are nearly twice the level of emissions from plant-based foods, and global food production is responsible for a third of all the planet-heating gases emitted from humans.

Livestock is responsible for 57% of food production emissions, compared to 29% for plant-based foods. Non-food products, like cotton and rubber, account for 14% of agricultural emissions.

Farmland management (38%) and land-use change (29%) represented a major share of total emissions. Rice (12%) is the largest plant-based commodity contributing to greenhouse gases, while beef (25%) is the largest animal-based commodity.

The entire system of food production causes 17.3 billion metric tonnes of greenhouse gases every year. Researchers say this release of gas doubles emissions in the U.S. and represents 35% of global emissions.

Atul Jain, a climate scientist at the University of Illinois and one of the authors of the study, said the emissions are higher than researchers expected and noted that policymakers should consider the results when controlling gas emissions. 

Beef plays a large role because raising livestock requires a large amount of land, and doing so produces a lot of methane, a greenhouse gas. 

Global meat production could increase 13% by the end of the decade for a total production of 366 million tonnes of meat, according to NGOs. 

According to the Food and Agriculture Organization for the United Nations, 45% of greenhouse gases are related to food production and processing. In 2013, livestock was responsible for 14.5% of global greenhouse gas emissions, according to the FAO. 

Just 1 kilogram of beef accounts for 70 kilograms in greenhouse gas emissions, compared to 2.5 kilograms of emissions for 1 kilogram of wheat.

The plant-based food industry made $3.7 billion in sales in 2018, and $670 million came from plant-based meat, according to a report by the Good Food Institute

If global greenhouse emissions continue to rise at their current rate, a third of the planet’s food population would be put at risk by the end of the century. 

Scientists say eating and farming habits must change to avoid global heating.