Temporary indirect artificial combustion reduces the effectiveness of the carbon sink for years to decades. Example: slash-and-burn agriculture.

Permanent indirect artificial combustion (PIAC) reduces the effectiveness of the carbon sink for centuries to millennia. Example: Cultural conversions from forest to range, range to agriculture, agriculture to urban.

Anthropogenic land degradation practices such as clear-cutting of forests, overgrazing of rangelands, overcultivation, salinization and desertification also lead to PIAC.