RP Sr has had two previous attempts to knock holes in the IPCC WG I and they were both embarassing failures ( and  (the latter expanded at 2a)). Emboldened by this, he’s had a third go which is just as bad.
Am I being too cruel and unkind here? I’m assuming anyone posting to the blogosphere on other peoples “errors” is fair game.
Anyway, this time its back to the dreaded butterfly effect (James, cover your eyes). There’s an RC post on it here (see-also my early post on the old blog); RPs first take on it is here and all the arguments get hashed out in the comments there (oh, and don’t miss the follow up which is even worse but probably easier to follow). Clearly RP hasn’t changed his views since; clearly no-one else agrees with him, and James previous comment “I’m more than a little surprised to see a State Climatologist apparently misunderstand this” still applies.
His point 2 is more interesting but still probably wrong. RP objects to “”Projecting changes in climate due to changes in greenhouse gases 50 years from now is a very different and much more easily solved problem than forecasting weather patterns just weeks from now”. Assuming “just weeks” means more than three, then the statement is trivially true since exact weather prediction out past this time appears to be impossible.