Soil as Carbon Storehouse: New Weapon in Climate Fight?
The damage or disappearance of ecologies and plant cover have caused significant soil degradation, which, it turns out, has released much CO2 into the atmosphere. In fact, the world’s cultivated soils have lost between 50 and 70 percent of their original carbon stock, according to recent research, much of which has oxidized upon exposure to air to become CO2. But new research is finding ways to recapture CO2 through land restoration.
“Recognition of the vital role played by soil carbon could mark an important if subtle shift in the discussion about global warming, which has been heavily focused on curbing emissions of fossil fuels. But a look at soil brings a sharper focus on potential carbon sinks. Reducing emissions is crucial, but soil carbon sequestration needs to be part of the picture as well, says Lal. The top priorities, he says, are restoring degraded and eroded lands, as well as avoiding deforestation and the farming of peatlands, which are a major reservoir of carbon and are easily decomposed upon drainage and cultivation.
Goreau says we need to seek opportunities to increase soil carbon in all ecosystems — from tropical forests to pasture to wetlands — by replanting degraded areas, increased mulching of biomass instead of burning, large-scale use of biochar, improved pasture management, effective erosion control, and restoration of mangroves, salt marshes, and sea grasses.
Scientists say that more carbon resides in soil than in the atmosphere and all plant life combined; there are 2,500 billion tons of carbon in soil, compared with 800 billion tons in the atmosphere and 560 billion tons in plant and animal life. And compared to many proposed geoengineering fixes, storing carbon in soil is simple: It’s a matter of returning carbon where it belongs.”