Nature can help reduce greenhouse gas, but only to a point

FLAGSTAFF, Ariz.--Plants apparently do much less than previously thought to counteract global warming, according to a paper to be published in next week's online edition of Proceedings of the National Academy of Sciences.

The authors, including Bruce Hungate of Northern Arizona University and lead author Kees-Jan van Groenigen of UC Davis, discovered that plants are limited in their impact on global warming because of their dependence on nitrogen and other trace elements. These elements are essential to photosynthesis, whereby plants remove carbon dioxide, a greenhouse gas, from the air and transfer carbon back into the soil.