Direct artificial combustion is the burning or organic matter to satisfy human needs, such as cooking, lighting, heating, cooling, and transportation.

Direct artificial combustion is accomplished through the burning of biomass [firewood, cowdung, trash-to-energy] or fossil fuel [petroleum, coal, natural gas].

Indirect artificial combustion occurs when humans act to reduce the processes by which carbon is removed from the atmosphere [clearing of mesic forests, rangelands to agriculture, agriculture/rangelands to urban].