Soil Holds Potential to Slow Global Warming, Multi-University Research Team Finds

Oct 5, 2017

What does soil have to do with climate change?

Managed well, soil’s ability to trap carbon dioxide is potentially much greater than previously estimated, according to a Stanford University-led research team that includes a Texas A&M University expert. They found that soil could significantly offset increasing global emissions.

Published in an Annual Review of Ecology, Evolution and Systematics article and a Global Change Biology paper, their work  emphasizes the need for more research into how soil – if managed well – could mitigate a rapidly changing climate. More research is needed to unlock soil’s potential to mitigate global warming, improve crop yields and increase resilience to extreme weather, the experts said.

Dr. Julie Loisel, assistant professor in Texas A&M’s Department of Geography contributed to the research and is a co-author of the Global Change Biology article.

“Soils are a frontier of carbon cycle science because they're deep, dark, heterogeneous and hard to sense with our satellites,” Loisel said. “But now is a great time to rescue data, tap into new technologies, and build better computer models that embrace the complexity of this biological, chemical, mineralogical, and physical enigma.”

Organic matter in soil, such as decomposing plant and animal residues, stores more carbon than do plants and the atmosphere combined. Unfortunately, the carbon in soil has been widely lost or degraded through land-use changes and unsustainable forestry and agricultural practices, fires, nitrogen deposition and other human activities, the experts said.

“Dirt is not exciting to most people,” said Stanford Earth system science professor Rob Jackson. “But it is a no-risk climate solution with big co-benefits. Fostering soil health protects food security and builds resilience to droughts, floods and urbanization.”

The greatest near-term threat comes from thawing permafrost in Earth’s northern reaches, which could release massive amounts of carbon into the atmosphere.

“Soil scientists and modelers have the knowledge and tools to reduce uncertainties pertaining to quantifying soil organic matter stocks and associated processes,” Loisel said.

Improving how the land is managed could increase soil’s carbon storage enough to offset future carbon emissions from thawing permafrost, the researchers found. Among the possible approaches: reduced tillage, year-round livestock forage and compost application. Planting more perennial crops, instead of annuals, could store more carbon and to reduce erosion by allowing roots to reach deeper into the ground. 

The researchers also found that about 70 percent of all sequestered carbon in the top meter of soil is in lands directly affected by agriculture, grazing or forest management – an amount that surprised the authors.  

Funding for the research came from the U.S. Department of Agriculture, the Gordon and Betty Moore Foundation, the National Science Foundation, the Swedish Research Council, the Inter-American Institute Collaborative Research Network, the Comision Sectorial de Investigacion Cientıfica and the Proyecto Plurianuales de Investigacion, the U.S. Geological Survey, the Bolin Climate Research Center at Stockholm University, the EU JPI Climate consortium, the U.S. Department of Energy and the Pacific Northwest National Laboratory.

By Leslie Lee, in conjunction with the Stanford Woods Institute for the Environment