Q. Which among the following is the largest terrestrial pool of carbon?
Answer: Soil
Notes: Soil carbon refers to the carbon held within the soil, mainly as organic content. Soil carbon is the largest terrestrial pool of carbon (2,200 Giga tonnes). Soil carbon plays a key role in the carbon cycle and thus is important in global climate models. It has been shown that l kg of carbon released from the soil constitutes 3.64kg of Co2 in the atmosphere. The exchange of carbon between soils and the atmosphere is a significant part of the world carbon cycle, which is extensive both spatially and temporally. Carbon, as it relates to the organic matter of soils, is a major component of soil and catchment health. With reference to Carbon sequestration, the soil is one of the largest reservoirs, where carbon could be restored.