[microtonal]

But it should make the scientists more circumspect about public policy recommendations.

From the article:

Climate models have been doing a fine job projecting warming for a long time. A recent study compared models as old as 1970 with observations made in the decades since. Some models warmed up too much, and some too little, but 14 of 17 past projections turned out to be consistent with the measured path of global average temperatures.

Scientists can not give definite answers in such complex systems, but it is the closest we can get in extrapolating the trajectory that we are on and computing what the effect of various measures is.

I am not sure what else one could base policy on.