Researchers found planting cover crops, optimizing grazing, and sowing legumes on rangelands could capture carbon from the atmosphere and store it in the soil. If these changes are implemented globally, the study suggests it could help drop global temperatures.
The study set out to model the potential impacts on climate change in the event of widespread adoption of agricultural management approaches known to increase soil carbon storage.
Through their models, the researchers calculated that when combined with aggressive carbon emission reduction, improved agricultural management could reduce global temperatures by about half a degree Fahrenheit by 2100. Further, they predict that with the addition biochar, a controversial soil additive obtained by burning crop residue in an oxygen-free environment, these practices could offset even more warming, potentially as much as 0.7 degrees Fahrenheit.
Those numbers may sound small, but in terms of global climate change the difference could potentially be huge. NASA’s global climate change factsheet states the planet’s average surface temperature has risen about 1.62 degrees Fahrenheit since the late 19th century, and the Intergovernmental Panel on Climate Change established carbon-reduction goals to limit average global warming to 3.6 degrees Fahrenheit above pre-industrial averages by 2100.
By focusing on low-tech methods of soil conservation already widely used to improve soil fertility and decrease erosion, the study’s authors point out that sequestering carbon may be a side effect of soil improvement but could have a big impact without requiring the adoption of new or unknown technologies.
“Agriculture is often portrayed as the villain in climate change,” said Whendee Silver, senior author and UC Berkeley professor of environmental science, policy and management. “What is exciting is that, not only can agriculture contribute to solving the problem, but it can do so in a way that actually improves agricultural soils.”
The study by UC Berkeley grad student Allegra Mayer, Silver, Zeke Hausfather of UC Berkeley’s energy and resources group and Andrew Jones of Lawrence Berkeley National Laboratory, was published Wednesday in the online journal Science Advances.