Food production accounts for approximately 30 percent of global greenhouse gas emissions. Currently, 21 percent of these emissions come from deforestation and land use changes that are a result of agriculture. These figures come from a report published by the Institute on the Environment at the University of Minnesota, with contributions from the U.N. Food and Agriculture Organization (FAO), the University of Minnesota, the CGIAR network, and international universities. The authors estimate that if land clearing for food production continues at its current pace, emissions from land use changes alone could increase by at least 30 percent in 2050. The baseline data used to develop the report comes from the Emissions Database of the FAO’s Statistics Division (FAOSTAT), which recently released statistics of global agricultural emissions to the year 2014. According to the FAO, this data is the first of its kind to be made publicly available.
The numbers from FAOSTAT indicate that greenhouse gas emissions from agriculture reached a record high in 2014, at a carbon dioxide (CO2) equivalent of 5.25 billion tons. The report, entitled “How Does Agriculture Change Our Climate,” focuses on emissions generated by deforestation and agricultural management. The authors cite ruminant livestock as contributing one-third of agricultural methane emissions—methane is a greenhouse gas which is 27 times more powerful than carbon dioxide. According to the report, “livestock supply one-third of protein for human consumption, but drive approximately 80 percent of non-CO2 emissions.” Rice production also emits 11 percent of total emissions from agricultural management.
Brazil and Indonesia generated almost 50 percent of the total loss of land from tropical deforestation, between 2000 and 2012. Deforestation from agriculture accounts for 75 percent of global land clearing, and greenhouse gases from global deforestation account for 10 percent of total emissions. Trees store CO2 in their trunks, branches, and root systems; once they are cleared to make space for livestock and agriculture, the CO2 is released into the atmosphere. The authors also say that developed countries, such as the United States and China, indirectly spur deforestation through their consumption of meat, palm oil, timber, and soy.
The report also highlights that 60 percent of human-induced nitrous oxide emissions—which has a global warming potential that is 300 times higher than CO2—comes from agriculture. This is mainly generated through inefficient fertilizer application. China, India, and the U.S. account for more than 55 percent of nitrous oxide emissions.
The report suggests that changes in land management are not enough to reduce emissions. Instead, the authors propose a three-pronged approach that also targets a change in consumer behavior: minimizing yield gaps via sustainable intensification, reducing food waste, and modifying dietary habits.
The report concludes with words of caution: “If we depend on current yield trends alone to meet future demand for food, we will need the entire global emissions allowance for keeping global average temperatures below two degrees Celsius. That would leave virtually no emissions for all other sectors, including energy production, industry, and transport.”