The graph below shows the predictions of James Hansen’s 1988 climate model overlaid (in blue) with observed temperatures. Hansen’s scenarios B and C have turned out to be very good predictions of what actually happened.
Of course, it is an article of faith amongst the global warming skeptics that the models are wrong, so what do they do?
Well, there are only two things you can do to make Hansen look bad — you can misrepresent the results of his model, or you can misrepresent the instrumental record.
The first approach is the one taken by Pat Michaels, who dishonestly erased scenarios B and C from Hansen’s graph. The second approach is the one taken by Willis Eschenbach over at Climate Audit. If you move your mouse over the figure above, you can see Eschenbach’s version. By doctoring the instrumental measurements so that they were all lower, he makes it look like Hansen’s model predicted more warming that what was actually observed.
The trick Eschenbach used was to use a single year for the baseline instead of the thirty year average that is normally used. Yes, it’s another version of the disingenous baseline game that produced all those bogus “global warming ended in 1998″ claims. Given the year to year variability of climate, by choosing the right year to use as a baseline you can manufacture almost any result you want.