In the Norwegian project, however, researchers have arrived at an estimate of 1.9C as the most likely level of warming.
Manmade climate forcing
"In our project we have worked on finding out the overall effect of all known feedback mechanisms," says project manager Terje Berntsen, who is a professor at the University of Oslo's Department of Geosciences and a senior research fellow at the Center for International Climate and Environmental Research Oslo (CICERO). The project has received funding from the Research Council of Norway's Large-scale Programme on Climate Change and its Impacts in Norway (NORKLIMA).
"We used a method that enables us to view the entire earth as one giant 'laboratory' where humankind has been conducting a collective experiment through our emissions of greenhouse gases and particulates, deforestation, and other activities that affect climate."
For their analysis, Professor Berntsen and his colleagues entered all the factors contributing to human-induced climate forcings since 1750 into their model. In addition, they entered fluctuations in climate caused by natural factors such as volcanic eruptions and solar activity. They also entered measurements of temperatures taken in the air, on ground, and in the oceans.
The researchers used a single climate model that repeated calculations millions of times in order to form a basis for statistical analysis. Highly advanced calculations based on Bayesian statistics were carried out by statisticians at the Norwegian Computing Center.
2000 figures make the difference
When the researchers at CICERO and the Norwegian Computing Center applied their model and statistics to analyse temperature readings from the air and ocean
|Contact: Thomas Keilman|
The Research Council of Norway