Global CO2 Models May Have Underestimated Plant Absorption
New research has questioned previous greenhouse gas models by suggesting that CO2 absorption by plants plays a greater role than previously thought.
Scientists from the University of Texas and Oak Ridge National Laboratory in Tennessee analysed mesophyll diffusion, the process by which CO2 spreads slowly within the inner tissue of leaves. Results suggest that between 1901 and 2010 the amount of carbon taken up by plants rose from 915 billion tonnes to 1,057 billion tonnes, a 16% increase. The researchers say that the findings may explain why levels of CO2 in the atmosphere are not rising as quickly as many current models predict.
Whilst greeting the work with interest, leading climate scientist Peter Rayner of the University of Melbourne pointed out that it does little to change the whole picture of climate change. “We already knew nature was working hard to hold CO2 concentrations in check,” he said. “This gives one explanation of how. The total effect over the 20th century is about 130 billion tonnes of CO2. That sounds like a lot but is less than four years of fossil fuel emissions. When it comes to controlling changes in CO2 in the atmosphere, nature is interesting but humans are in control. It’s our problem and our choice.”
The research has been published in the journal Proceedings of the National Academy of Sciences.