Soil organic carbon is a measureable component of soil organic matter. Organic matter makes up just 2–10% of most soil's mass and has an important role in the physical, chemical and biological function of agricultural soils.Organic matter contributes to nutrient retention and turnover, soil structure, moisture retention and availability, degradation of pollutants, carbon sequestration and soil resilience.Sequestering carbon in SOC is seen as one way to mitigate climate change by reducing atmospheric carbon dioxide. The argument is that small increases of SOC over very large areas in agricultural and pastoral lands will significantly reduce atmospheric carbon dioxide. For the reduction to be long-lasting, organic matter would have to be in the more stable or resistant fractions