Growing perennial grasses could help curb climate change

Climate change is driving up temperatures and causing more frequent heatwaves in the American Midwest. However, according to a new study led by the University of Maryland, growing one particular type of perennial grass – the giant miscanthus – could cut Midwest warming by one degree Celsius. These findings offer new insights into nature-based mitigation strategies for climate change, and could have a significant impact on environmental conservation, agricultural sustainability, and food crop and energy production.   

The giant miscanthus grows up to ten feet tall, and has wide bamboo-like stems and green leaves, creating a large canopy that could help lowering regional summer temperatures, while increasing humidity, rainfall, and overall crop productivity. This plant is noninvasive, water-efficient, requires little fertilizer, and can grow on marginal land, or land with little or no agricultural or industrial value due to poor soil conditions. Thus, the Midwest heartland – known for its large amount of marginal land that often goes unused – could offer the perfect conditions for the cultivation of this grass.

“Growing perennial grasses on marginal land not only can reduce soil erosion, restore carbon stocks, and provide feedstocks for biofuels and bioproducts, but can also be an effective mitigation strategy to contain regional climate change, preventing the U.S. agricultural heartland from the warming-and-drying trend currently projected,” said study co-author Xin-Zhong Liang, an environmental scientist at the University of Maryland.

By pairing a dynamic crop growth model with a regional climate model, Dr. Liang and his colleagues have found that the giant miscanthus has the potential not only to cool the land, but also to increase summer precipitation by 14 to 15 percent. While the temperature declines will be greatest in regions with the most miscanthus, the changes in precipitations could occur even hundreds of miles beyond, due to atmospheric circulation.

“Global temperatures will continue to rise due to climate change, even if we are able to curb greenhouse gas emissions and develop new technologies for carbon removal,” said Laura Lautz, a program director in the Division of Earth Sciences of the National Science Foundation (an organization which funded the current study). “This research adds to our toolbox of strategies to minimize the impacts of future warming, increase food security, and improve the resilience of agricultural systems.” 

The study is published in the journal GCB-Bioenergy.

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By Andrei Ionescu, Earth.com Staff Writer