The main agricultural contributions to greenhouse gases are methane and nitrous oxide. Methane is produced by animals and their manure. Nitrous oxide is emitted from soil, particularly when nitrogen fertilizers are used. Each gas has a different potency, so weight alone does not indicate its effect. By weight, methane has 21 times and nitrous oxide 310 times the greenhouse effect of carbon dioxide.
South America is the region with the highest carbon dioxide equivalent emissions of agricultural methane and nitrous oxide per person. The territory with the highest emissions per person is New Zealand, at the equivalent of 9.7 tonnes of carbon dioxide in 2002.