A new study published in Nature Sustainability maps the Earth’s reserves of what is called “irrecoverable carbon”—that is to say, those stores of carbon in nature that, if released into the atmosphere, would not be able to be restored in the timeframe required to deal with climate change. These stores include wetlands and old-growth forests, which take longer to replenish.

Irrecoverable carbon represents 20% of the total manageable ecosystem carbon. Globally, 79.0 Gt (57%) of irrecoverable carbon is found in biomass while 60.0 Gt (43%) is in soils. […] The largest and highest-density irrecoverable carbon reserves are in the tropical forests and peatlands of the Amazon (31.5 Gt), the Congo Basin (8.2 Gt) and Insular Southeast Asia (13.1 Gt); the temperate rainforest of northwestern North America (5.0 Gt); the boreal peatlands and associated forests of eastern Canada and western Siberia (12.4 Gt); and mangroves and tidal wetlands globally (4.8 Gt).

The study argues that such reserves should be considered unexploitable; about 48 percent of it is already within protected or indigenous lands. About half the irrecoverable carbon sits on 3.3 percent of the world’s land area. [ScienceNews, GIS Lounge]