Soil carbon sequestration - myths and mysteries

Abstract

The balance between carbon (C) sequestration (or storage) in various sinks such as soils and vegetation and that released to the atmosphere as carbon dioxide (CO2) is topical, given the global warming/climate change projections. However, there is a considerable degree of uncertainty surrounding what options are available, how realistic they are and, more specifically (from a soil perspective), what role does soil C play in mitigating the effects of CO2 emissions. This paper tries to place soil C in a global perspective and to assess how realistic it is for significant soil C sequestration to occur in different land use systems. In order to do that, we need to provide some background on soil organic matter, the main soil C pool which can be influenced through land management. This will consider the different forms of organic C in soil, how they can be measured and the role they play in determining soil functions and properties.