A Reuters article on Monday reported on a phenomenon that doesn’t seem to be well recognized or understood outside the soil science and erosion control communities, but that has frightening implications. Among the problems caused by accelerated erosion, the article says, is the potential release of large amounts of carbon and other greenhouse gases to the atmosphere.
A recent report from the United Nations’ Environment Programme is the source of Reuters’ information, but the idea isn’t new. For example, this 2001 article from Erosion Control examines the relationship between soil erosion and the release of greenhouse gases; basically, organic matter in disturbed soil decays more quickly than that in intact soil and releases more carbon, methane, and nitrous oxide.
According to the UN report’s figures, the top meter of soil stores about three times more carbon than that currently in the atmosphere. Poor agricultural practices, deforestation, and other activities that degrade the soil and cause more rapid release of carbon; the report estimates that since the 19th century, 60% of the carbon stored in soils and vegetation has been lost due to agriculture and urbanization.
The report recommends using financial incentives for improved land use, including trading of carbon credits for soils. It also calls for development of a consistent way to measure changes in soil carbon.