During the Climate Change negotiations in Cancun Mexico, Dr Mark New of Oxford University, UK, expert in this area will discuss that the closer we get to 4C warming the less able the Earth is able to absorb CO2.
Assuming that all Global negations are adhered to in the future, they wouldn’t be enough to stem the rise in temperature to only 2C. Stressed by Bob Watson, of the chief scientist at the Department for Environment, Food and Rural Affairs states, "Two degrees is now a wishful dream."
http://www.guardian.co.uk/environment/2010/nov/28/cancun-climate-summit-weather/print