Trees are feasting on decades of carbon dioxide emissions and growing bigger as a result, according to a new study of U.S. forests.
Scientists tracked wood volume in 10 different tree groups from 1997 to 2017, finding that all except aspen-birch grew larger. Over that same period, carbon dioxide levels went from 363 parts per million to 405 parts per million, owing largely to the burning of fossil fuels. More abundant CO2 accelerates photosynthesis, causing plants to grow faster, a phenomenon known as “carbon fertilization.” The findings were published in the journal Nature Communications.
The study suggests that even as warming threatens forests by fueling drought, insect infestations, and wildfires, rising CO2 levels mean that tree-planting is an increasingly cost-effective method of fighting climate change, as the same number of trees can sequester more carbon, said Brent Sohngen, an environmental scientist at Ohio State University and coauthor of the study.
“While we’re putting billions of tons of carbon dioxide into the atmosphere, we’re actually taking much of it out just by letting our forests grow,” Sohngen said in a statement. “We should be planting more trees and preserving older ones, because at the end of the day they’re probably our best bet for mitigating climate change.”