The graph shows three different scenarios, differing in the amount of carbon dioxide projected to be emitted, something Hansen could not have known in advance.
The top line is the most extreme projection, if civilizations’ carbon use intensity went up significantly. The bottom line is what would happen if carbon intensity dropped significantly starting in the year 2000. The middle line is what would happen with business as usual.
The solid line represents the actual ongoing instrumental temperature record up to 1988.
Ten years after James Hansen’s testimony to congress, climate change denier extraordinaire Patrick Michaels appeared before it. He challenged James Hansen’s projections made in the above graphs.
This is what actually happened, Michaels claimed, and this is what Hansen said would happen. Then Michaels presented the following graph to congress, claiming it represented what Hansen said in 1988. See, said Michaels triumphantly, Hansen’s projections were way out of line.
Except that the graph that Michaels used represented Hansen’s projections only if carbon use increased significantly in the interim. It didn’t. In fact, carbon use in 1998 paralleled what Hansen had projected in the other two scenarios. If he wanted to be intellectually honest, those two were the projections that Michaels should have presented to congress.
The fact that he didn’t present them at all, in fact erased them, demonstrates Michaels to be far from intellectually honest.
So how good were Hansen’s projections in the other two scenarios? As you can see by the graph below, which is the same graph from 1988 updated with instrumental data to 1998, that Hansen’s projections, far from being wrong, were dead-on accurate.
Michaels deliberately misled, that is, lied to congress about Hansen’s work. His nose is so long, it enters a room two minutes before he does.
For your interest, here is Hansen’s diagram updated to 2005, still bulls-eyeing his original predictions.
If Patrick Michaels is the best the climate change deniers can muster to defend their cause, then their cause is intellectually bankrupt.
But we all knew that anyway, didn’t we?