A new study just released by the Massachusetts Institute of Technology predicts that the Earth's median surface temperature could rise 9.3 degrees Fahrenheit (5.2 degrees Celsius) by 210o, about twice what was predicted just six years ago. The study cations that it will take "rapid and massive action" to prevent a rise this large.
Another article in Nature magazine claims that without major curbs on fossil fuel use, the earth will warm 2 degrees Celsius by 2050. More than 100 nations support the goal of keeping warming below 2C.
About three-quarters of the world's fossil fuel reserves must be left unused if this goal is to be met. In the last 250 years we burned a half trillion tonnes of carbon. At our present rate we will burn the next half trillion in 40 years.
Author Myles Allen comments that "Climate policy needs an exit strategy; as well as reducing carbon emissions now, we need a plan for phasing out net emissions entirely."