Poor farming practices and deforestation are threatening to compound climate change by degrading the soil, according to a report set to be formally published next week. Soil erosion both limits the growth of carbon-absorbing plants, and releases the carbon that the ground has already absorbed, BBC News explains.
Soil holds three times the amount of carbon contained in the atmosphere.
The report is authored by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), and will be formally presented on Monday, May 6th, following their meeting this week.
Over three billion people, nearly half of the world’s population, are dealing with degraded soils, according to the group’s chairman, Professor Sir Bob Watson, former leader of the Inter-governmental Panel on Climate Change (IPCC).
“There’s no question we are degrading soils all over the world. We are losing from the soil the organic carbon and this undermines agricultural productivity and contributes to climate change. We absolutely have to restore the degraded soil we’ve got.”
Scientists are still unclear on the full extent of global soil degradation, but some regions stand out in how they’ve been affected. Soil scientists in India and China, the world’s largest nations, have voiced concerns that soil decline could inhibit their food production. In South America, rapid deforestation is driving soil degradation. Sub-Saharan Africa has also seen severe degradation.
In the US, some areas are recovering as forests return to land abandoned by small farms, while other areas are still in decline. In southwest England, corn farming leaves soil exposed, leading to losses when heavy rainfall occurs, which is expected to become more common with climate change.
Allowing forests to grow back is the most straightforward solution. But some farmers are also changing their approach to farming to benefit the soil, planting cover crops in winter to protect the soil, for example.
“The thin layer of soil covering the Earth’s surface represents the difference between survival and extinction for most terrestrial life. Only 3% of the planet’s surface is suitable for arable production and 75 billion tons of fertile soil is lost to land degradation every year,” says Cranfield University soil expert Professor Jane Rickson.
According to Rickson, only about one centimeter of soil is formed every 300 years.
“Governments have focused on climate change far more than they have focused on loss of biodiversity or land degradation. All three are equally important to human wellbeing.”