Washington, Nov 27 (IANS): The most draconian projections of rising temperatures due to the doubling of atmospheric carbon are unlikely, says a new study.

The rate of global warming may be less severe than projected by the Intergovernmental Panel on Climate Change report in 2007.

Study authors from Oregon State University say that global warming is real and that increases in atmospheric CO2 will have multiple serious impacts, the Science journal reported.

"Many previous climate sensitivity studies have looked at the past only from 1850 through today, and not fully integrated paleoclimate date, especially on a global scale," said Oregon researcher Andreas Schmittner, who led the study.

"When you reconstruct sea and land surface temperatures from the peak of the last Ice Age 21,000 years ago... and compare it with climate model simulations of that period, you get a much different picture," a Oregon statement quoted him as saying.

"If these paleoclimatic constraints apply to the future, as predicted by our model, the results imply less probability of extreme climatic change than previously thought," Schmittner added.