Study of CO2 absorption by leaves suggests models overestimate atmospheric levels

BBC : One of the variables that climate models include is a measure of how much atmospheric carbon dioxide is absorbed by plants. According to a new study of the absorption process by Lianhong Gu of Oak Ridge National Laboratory and his colleagues, the amount plants absorbed between 1901 and 2010 was actually 16% higher than most models had estimated. To reach that conclusion, Gu’s team studied mesophyll diffusion—the way that CO₂ spreads within leaves. Their analysis of several climate models has also led them to believe that the amount of atmospheric CO₂ has been overestimated by 17%. They say their finding regarding plants’ CO₂ absorption would account for that discrepancy. Although the researchers’ work may lead to an adjustment of climate models, it is unlikely to alter the general implications of increasing levels of atmospheric CO₂ on climate change.