We are at a proverbial crossroads when it comes to climate change and avoiding its worst impacts. Total annual global greenhouse gas emissions need to drop to a net of 41 gigatons of carbon dioxide equivalent (GtCO2e) in order to have a chance of limiting warming to 1.5 degrees Celsius. Total annual global emissions of greenhouse gases (GHG) in 2012 were 52 GtCO2e.
Although the situation may seem dire, there is something that can help sequester vast amounts of carbon dioxide emissions, and it is called regenerative organic agriculture for soil-carbon sequestration. More than 100 percent of current annual carbon emissions could be sequestered by switching to regenerative organic agriculture, according to a new report from the organic farming nonprofit Rodale Institute.
Regenerative organic agriculture is a term coined by Robert Rodale, son of American organic pioneer and Rodale Institute founder J.I. Rodale. It is an organic farming system that does not use synthetic pesticides, which can do damage to the soil, or nitrogen fertilizer, which causes nitrous oxide, a GHG 300 times more potent than carbon dioxide. Nitrous oxide accounts for about 40 percent of all GHG emissions globally. Regenerative organic agriculture uses conservation tillage, cover crops, residue mulching, composting and crop rotation and can “easily” keep annual emissions within the desirable range of 41 to 47 GtCO2e by 2020, according to the report.
The most common agricultural practices today are doing the opposite of sequestering emissions: GHG emissions from the agriculture sector accounted for 9 percent of total GHG emissions, according to Environmental Protection Agency (EPA) estimates. GHG emissions from agriculture have increased by 19 percent since 1990.
The practices used in regenerative organic agriculture not only pose the best chance for sequestering vast amounts of carbon, but they are also good for the soil. They “minimize biota disturbance and erosion losses while incorporating carbon rich amendments and retaining the biomass of roots and shoots,” the reports authors wrote. All of those things contribute to carbon sequestration.
Take conservation tillage, which is not widely practiced in organic farming but is “integral to soil- carbon sequestration,” the report states. Switching to conservation tillage would improve soil structure plus reduce carbon emissions while contributing to increases in soil organic carbon. No-till farming systems are also a part of regenerative organic agriculture as they have the best chance of reversing the “trend of soil organic carbon losses in agriculture” when used with cover-cropping and enhanced crop rotations. No-till organic farming has been shown to increase soil organic carbon by 9 percent after two years and 21 percent after six years.
Conventional farming already uses cover crops. Travel to California’s San Joaquin Valley and you might see cover crops planted between vineyard rows. Cover crops are very good for the soil as they discourage wind and water erosion. They also increase soil carbon and reduce nitrogen leaching. The report cites other benefits of cover cropping, including reduced weed pressure, decreased water runoff, improved soil structure and water infiltration and reduced evaporation.
Image credit: Chesapeake Bay Program