The Wall Street Journal looks at the IAC report and considers one of its key findings, namely that the IPCC has downplayed uncertainties in the science of global warming. In the process they consider McShane and Wyner's paper on the reliability (or lack of it) of proxy-based temperature reconstructions and also a new paper on the sensitivity of the Amazon rainforest to drought. It looks as though this sensitivity is not really understood because nobody knows how the Amazon will respond to rising CO2 levels.
As the Journal puts it:
None of this proves or disproves anything, except that our understanding of how our climate works is still evolving. Is it too much to ask the climate establishment to acknowledge as much?