Global greenhouse gas emissions shares 2018, by sub sector

The world currently produces the equivalent of 50 billion metric tons of carbon dioxide (GtCO2e) every year from activities such as fossil fuel combustion and agriculture. In 2018, global greenhouse gas emissions totaled 48.9 GtCO2e, of which road transportation accounted for 12.5 percent. Energy use for residential buildings accounted for a similar share of global emissions that year, at 11.4 percent.

Most polluting sectors

The electricity and heat sector was the largest contributor to GHG emissions in 2018, accounting for 32 percent of the global total. Combined with transportation, these two polluting sectors account for almost half of global greenhouse gas emissions. Carbon dioxide (CO2) makes up the majority of greenhouse gas emissions produced by these sectors. In 2020, the power industry and transportation produced 56 percent of global CO2 emissions.

Environmental impact of food

While the agriculture sector accounts for 12 percent of global emissions, the overall impacts of the global food system are considerable. It is estimated that global food system emissions totaled 18 GtCO2e in 2015. One of the largest contributors to food emissions is the production of meat, specifically beef.