Land use, land-use change, and forestry. Human activities impact terrestrial sinks through land use, land-use change and forestry (LULUCF) activities, consequently, affecting the carbon cycle; the exchange of CO2 between the terrestrial biosphere system and the atmosphere. The LULUCF sector covers emissions and removals of greenhouse gases resulting from direct human-induced land use, land-use change and forestry activities. Activities within the LULUCF sector can provide for a relatively cost-effective way to offset emissions, either by increasing removals of GHGs from the atmosphere (e.g. by planting trees or managing forests), or by reducing emissions (e.g. by curbing deforestation). Such activites can earn saleable removal units (see RMU), that can be traded and sold on the emissions trading market (see also Emissions trading).