NASA Finds Trees and Insect Outbreaks Affect Carbon Dioxide Levels

Winds and changing climate converted parts of Oklahoma, Kansas, Colorado and Texas into a giant ’dust bowl’ in the 1930s. In response, the 1937 ’Shelterbelt Project’ involved the planting of trees to reduce erosion and provide relief from the biting winds that blew soil from farms and drove people west to California. Now, almost 75 years later, NASA scientists have found that planting trees also can significantly reduce carbon dioxide in the atmosphere.

Tree planting and insect control could greatly affect Earth’s greenhouse gases – those gases in the atmosphere that warm the planet – according to NASA scientists who presented their findings this December during the American Geophysical Union’s fall meeting in San Francisco.

“Planting trees on marginal agricultural lands could ’sequester’ carbon and offset at least one-fifth of the annual fossil fuel emission of carbon in the United States,” said Christopher Potter, a scientist at NASA Ames Research Center in California’s Silicon Valley. “Scientists also have found that outbreaks of plant-eating insects may be linked with periodic droughts and heat waves in North America, which can trigger large seasonal losses of carbon dioxide back to the atmosphere.” Potter added.

NASA scientists report a satellite-driven computer model that predicts forest re-growth conservatively projects that 0.3 billion metric tons of carbon could be ’stored’ each year in trees growing on relatively low-production crop or rangeland areas in the United States.

The second study involves large-scale disturbances to greenhouse gases detected using global satellite data. “A historical picture is emerging of periodic droughts and heat waves, possibly coupled with herbivorous insect outbreaks, as among the most important causes of ecosystem disturbances in North America,” Potter said.

According to scientists, the reason insects affect the planet’s carbon dioxide level is that the six-legged creatures eat and kill trees and other vegetation. When the amount of greenery is reduced on Earth, the remaining plants take in less carbon dioxide. As a result, say scientists, more of this gas remains in the air, instead of being trapped in wood, fiber, leaves and other foliage parts.

The findings about tree planting and insect control are the subjects of two technical papers, co-authored by Potter. Other co-authors of the paper related to tree planting, include Matthew Fladeland, also of NASA Ames, and Steven Klooster, Vanessa Genovese and Marc Kramer, all from California State University, Monterey Bay, Calif., all of whom are co-located at NASA Ames.

Potter’s co-authors for the second ’insect’ study include: Pang-Ning Tan, Michigan State University, East Lansing, Mich.; Vipin Kumar, University of Minnesota, Minneapolis; and Klooster.