CO2 Sensitivity Decrease
The new models predict that given a doubling in CO2 levels from pre-industrial levels, the Earth's surface temperatures will rise by 1.7 to 2.6 degrees C.
That is a much tighter range than suggested by the Intergovernmental Panel on Climate Change (IPCC)'s 2007 report, which suggested a rise of between 2 to 4.5 degrees C.
The new analysis also reduces the expected average surface temperatures to just over 2 degrees C, from 3.
The authors stress the results do not mean threat from human-induced climate change should be treated any less seriously, explained palaeoclimatologist Antoni Rosell-Mele from the Autonomous University of Barcelona, who is a member of the team that came up with the new estimates.
But it does mean that to induce large-scale warming of the planet, leading lead to widespread catastrophic consequences, we would have to increase CO2 more than we are going to do in the near future, he said.