worse than we thought – atmospheric concentration of CO2!

jaw_droppingThe MIT Integrated Global System Model is used to make probabilistic projections of climate change from 1861 to 2100.

Since the model’s first projections were published in 2003 substantial improvements have been made to the model and improved estimates of the probability distributions of uncertain input parameters have become available.

The new projections are considerably warmer than the 2003 projections, e.g., the median surface warming in 2091 to 2100 is 5.1°C compared to 2.4°C in the earlier study.

Their median projection for the atmospheric concentration of carbon dioxide in 2095 is a jaw-dropping 866 ppm. ClimateProgress, 23 Feb 2009