Emissions related to energy are tied to a variety of sources, including electricity and heat production, manufacturing and construction, and transportation. About two-thirds of emissions from agricultural sources comes from cattle belching, which releases methane, and the use of fertilizers, but also manure management, rice cultivation, field burning, and fuel use on farms. Industrial processes refers to emissions produced by industrial activities unrelated to energy, such as the carbon dioxide emitted during cement production, or emissions released in the use of soda ash, a material used in glass manufacturing and the production of soap and detergent. Land-use change and forestry emissions come from activities such as deforestation. Waste emissions are produced by waste elimination processes such as incineration and landfilling; as organic material in landfills disintegrates, for example, it produces methane. Bunker fuels power ships and aircraft. The term refers to the thick, viscous oil left over after crude oil goes through the refinery process to extract gasoline and diesel. Only large, complex engines like ship engines are able to heat up bunker fuel enough for it to combust.
It is also possible to identify individual company contributions to climate change over time and by year.