New research suggests climate models don't give plants enough credit for absorbing excess carbon dioxide from the air. But is the discrepancy enough to make a difference in global climate change?
Earth's plant life may soak up more carbon dioxide from the atmosphere than previously thought, according to a new study. And since CO2 emissions from burned fossil fuels are also the main driver of man-made climate change, that raises an obvious question: Are trees saving the world from us?
It's widely known that plants need CO2 for photosynthesis, but the study's authors say current computer models of Earth's climate underestimate how much CO2 is absorbed by vegetation overall. That's because most climate models don't factor in the way CO2 diffuses inside a leaf's mesophyll tissue, causing the models to misjudge plants' global CO2 intake by as much as 16 percent.
More photosynthesis is good, but can a 16 percent discrepancy slow down climate change? Some news coverage and commentary has suggested it might, raising the possibility trees and other land plants could buy us more time to curb greenhouse gas emissions. Yet several prominent scientists — including a co-author of the new study — tell MNN such interpretations are mostly hot air.
"No, it would not reduce the urgency of reducing emissions," says Lianhong Gu, an environmental scientist at Oak Ridge National Laboratory who helped produce the study. "The climate change associated with fossil fuel use is much bigger than the response of plants to CO2."