Future global warming will not only depend on the amount of emissions from man-made greenhouse gasses, but will also depend on the sensitivity of the climate system and response to feedback mechanisms. By reconstructing past global warming and the carbon cycle on Earth 56 million years ago, researchers from the Niels Bohr Institute among others have used computer modelling to calculate the potential perspective for future global warming, which could be even warmer than previously thought. The results are published in the scientific journal, Geophysical Research Letters. Global warming from greenhouse gas emissions depends not only on the size of the emissions, but also on the warming effect that the extra amount of gas has on the atmosphere. This effect, called climate sensitivity, is usually defined as the warming caused by the doubling of the amount of CO2 in the atmosphere. Climate sensitivity depends on a number of properties of the earth’s climate system, such as the composition of clouds and cloud cover. “The research shows that climate sensitivity was higher during the past global, warm climate than in the current climate. This is bad news for humanity as greater climate sensitivity from warming will further amplify the warming,” says Professor Gary Shaffer, University of Magallanes, Chile, and the Niels Bohr Institute, University of Copenhagen.
From Niels Bohr Institute, University of Copenhagen
Photo Credit John Vlahakis