Reality Checking the Forecasts

At the core of my climate video is a reality check on catastrophic warming forecasts, which demonstrates, as summarized in this post, that warming over the next century can’t be much more than a degree if one takes history as a guide.  The Reference Frame has a nice summary:

Well, we will probably surpass 560 ppm of CO2. Even if you believe that the greenhouse effect is responsible for all long-term warming, we have already realized something like 1/2 (40-75%, depending on the details of your calculation) of the greenhouse effect attributed to the CO2 doubling from 280 ppm to 560 ppm. It has led to 0.6°C of warming. It is not a hard calculation that the other half is thus expected to lead to an additional 0.6°C of warming between today and 2100.

Other derivations based on data that I consider rationally justified lead to numbers between 0.3°C and 1.4°C for the warming between 2000 and 2100. Clearly, one needs to know some science here. Laymen who are just interested in this debate but don’t study the numbers by technical methods are likely to offer nothing else than random guesses and prejudices, regardless of their "ideological" affiliation in the climate debate.