A collection of “low-tech, time-tested forest, farm, and land management techniques” could offset 21% of the United States’ greenhouse gas emissions, InsideClimate News reports, although it would take a carbon price of at least US$100 per ton for those strategies to meet U.S. targets under the 2015 Paris Agreement.
“It’s the same as if every car and truck in the country stopped polluting the climate,” said Joseph Fargione, science director for The Nature Conservancy North America region and lead author of the study published last week in the journal Science Advances. “There’s much bigger potential than most people realize.”
Carbon Brief’s coverage includes a graph and a map that illustrate the main potential in the study.
Fargione coordinated a team of 38 researchers who “spent more than two years looking at ‘natural climate solutions’—a range of strategies that includes planting trees in cities, preventing the conversion of natural grassland to farmland, and shifting to fertilizers that produce less greenhouse gas emissions,” InsideClimate states. And although the $100 per ton carbon price would be needed to meet the country’s Paris targets, “the report finds that many of these solutions cost a fraction of that—or nothing at all—and have additional benefits and incentives, including cleaner water, better air, and more productive soil.”
“There’s a range of reasons that people might choose to invest in these natural climate solutions beyond carbon,” Fargione told ICN, noting that forest thinning practices in California would improve carbon storage while reducing the risk of cataclysmic wildfires.
Out of a list of 21 natural climate solutions, the team identified reforestation as the most important, with potential to store or draw down nearly 307 million tonnes of carbon, mainly in the country’s northeastern and south-central regions. Natural forest management strategies, including extended harvest cycles and reduced-impact logging, would mitigate another 267 megatonnes.
The study found another 440 megatonnes of carbon dioxide storage per year in various changes in agricultural practices, writes InsideClimate reporter Georgina Gustin. The research team “looked at a number of solutions in agriculture, including avoiding the conversion of grassland to cropland, using cover crops planted in the off-season that add carbon to the soil, and using fertilizer more judiciously.” Their list of solutions included use of biochar to build healthier soil, and “alley cropping” techniques that place trees between crops.
The research also identified more than 12 million acres of cropland that could be restored to grasslands, forests, or wetlands, with no impact on food production.