According to this information sheet, "if nothing is done to reduce emissions, current climate models predict a global warming of about 2°C between 1990 and 2100." Of course they do, but are the predictions correct? Since they come from models that are admittedly imperfect in many important respects and, on top of that, are fed greenhouse gas emission scenarios that are founded on assumptions, one can get a wide range of answers, much wider, in fact, than the 1 to 3.5°C warming that the Information Kit suggests.
In light of these fundamental problems with the global warming predictions of the climate models, it seems unnecessary to comment on any of their more specific or regional predictions, as the Information Kit truly notes that these latter predictions "are much more uncertain." For example, the Kit states that the frequency and intensity of extreme weather events such as storms and hurricanes may change in some parts of the world; but the explanatory text admits that the models cannot even tell us if they will increase or decrease.
The final point of this section sternly warns that "rapid and unexpected climate transitions cannot be ruled out." We agree. It is very difficult to totally rule out almost anything. Is it not, therefore, even easier to not rule out a mere 1°C extension of the lower boundary of the range of global warming that may be expected to accompany a doubling of the air's CO2 content? If we must heed the warning of rapid and unexpected climate transitions, we should be willing to entertain the possibility that a doubled atmospheric CO2 concentration may produce no change in climate at all, due to some "unexpected" feedback that perhaps no one has yet identified.