Maintaining and enhancing ecological carbon sequestration

Abstract

Terrestrial ecosystems sequester large amounts of organic carbon (C) in their pools of living and dead biomass. Management actions that increase C uptake and storage in ecological C pools, or that reduce C release from them, contribute to a society's climate change mitigation objectives. They do this by reducing the rate of accumulation of CO2 and its radiative equivalents in other greenhouse gases (GHGs) in the atmosphere. Trading systems for GHG credits recognize the validity of ecological offset projects that result in increased C storage in the living and/or dead organic matter of ecosystems. In some circumstances, projects that reduce C release from existing high-C ecosystems are also considered to provide legitimate offsets. Some ecological carbon-offset projects have been criticized from a variety of perspectives, but the problems can mostly be dealt with by means of improved regulations and management actions. In addition to their contribution to climate change mitigation, projects that maintain or accumulate ecological carbon offsets often result in important co-benefits through the conservation of biodiversity and non-carbon environmental services, which are also important societal goals. The co-benefits are, however, much less substantial for projects based on intensively managed ecosystems, such as no-till agroecosystems and plantation forests, compared with those that restore or maintain habitats that are more natural in character.