Because they’re the real experts and they know better.
We know the sun is virtually erupting with magnetic storms, whose output fluctuates dramatically. It would similarly be impossible to predict how that energy affects our spinning planet....when it hits our atmosphere, day or night, at what intensity, what part of planet is most affected (land or sea, moist or humid, hot or cold air), etc.
It seems plain as day and night that's why weather can't be predicted with any certainty even for more than a few hours. The big ball in the sky runs in overdrive some of the time, and then coasts along at a leisurely pace at others.
------------------------------------end of theory
The CJR author seemed a bit dumb-founded at times, trying to determine what makes the neanderthals gw deniers. Notice he avoided some of the known events like the Mid Evil Warming Period which immediately casts suspicions on some grandiose warming theory.