Climate change DOUBT: Study shows carbon dioxide levels in atmosphere are OVERSTATED
CLIMATE change forecasts may be overestimates due to a failure to take into account how plants absorb carbon dioxide, scientists warned today. ● They said the impact of rising CO2 levels on plant growth has been underestimated by 16 per cent. And as plants absorb CO2, this has led to overestimates of how much of the greenhouse gas is left in the atmosphere. Climate sceptics said the study by American scientists is yet more proof that the science of climate change is not settled and is instead much more complicated than previously thought. And one leading climate scientist said the paper suggests that cuts in emissions of greenhouse gases may not need to be as deep to keep global warming below what is seen as the critical increase of 2C. This casts doubt on the drive for costly anti-pollution measures such as wind farms. Climate change is widely blamed on man's burning of fossil fuels such as coal, oil and gas which release greenhouse gases such as carbon dioxide that trap the heat in the atmosphere. The study in the Proceedings of the National Academy of Sciences focusses on the slow diffusion of CO2 in plant leaves, with particular attention to the mesophyll or their inner tissue. It concludes: "Carbon cycle models that lack explicit understanding of mesophyll diffusion will underestimate historical and future terrestrial carbon uptake. "Consequently, they will overestimate historical and future growth rates of atmospheric CO2 concentration due to fossil fuel emissions, with ramifications for predicted climate change."