Unlike previous global warming models, a new study suggests that high carbon dioxide levels may have less impact on the rate of global warming.

Researchers said the study, funded by the U.S. National Science Foundation, predicts the doubling of atmospheric carbon dioxide from pre-industrial standards will raise temperatures an average of 2.3 degrees C, as compared to the 2007 United Nations' Intergovernmental Panel on Climate Change estimate of 3 degrees C.

Other estimates predicted temperature rise of up to an average of 10 degrees C, which is unlikely, researchers said.

"When you reconstruct sea and land surface temperatures from the peak of the last ice age 21,000 years ago - which is referred to as the Last Glacial Maximum - and compare it with climate model simulations of that period, you get a much different picture," lead author Andreas Schmittner told BBC News.

"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," he added.

The researchers based their study on ice age land and ocean surface temperature obtained by examining ices cores, bore holes, sea floor sediments and other factors. Comparing these with paleoclimatic data, the researchers found very small differences in ocean temperatures then compared to now.

"Yet the planet was completely different - huge ice sheets over North America and northern Europe, more sea ice and snow, different vegetation, lower sea levels and more dust in the air," Schmittner said.

"It shows that even very small changes in the ocean's surface temperature can have an enormous impact elsewhere, particularly over land areas at mid- to high latitudes."

He warned that unabated use of fossil fuels could lead to similar warming of sea surfaces today.