Skip to content

On Monday an independent review found that the U.N.’s Intergovernmental Panel on Climate Change has downplayed uncertainties surrounding climate science. The review also found that the IPCC needs more robust safeguards against conflicts of interest, that it had committed “unnecessary errors” by failing to meet its own standards, that it had inadequately flagged its use of nonscientific sources, that it made claims with “high confidence” based on “weak evidentiary basis,” and that it gave short shrift to dissenting scientists.

And for all that, the review added that the IPCC “has been successful overall and has served society well.”

This week’s report, in keeping with three earlier investigations into the University of East Anglia’s Climatic Research Unit, limited its inquiry to the “processes and procedures” of the IPCC. While it found those wanting, it also saw no need to question their scientific result.

That’s too bad, since the state of the science has moved on considerably since the IPCC concluded in its 2007 report that climate change was “unequivocal.” A forthcoming paper in Annals of Applied Statistics details the uncertainties in trying to reconstruct historical temperatures using proxy data such as tree rings and ice cores. Statisticians Blakeley McShane and Abraham Wyner find that while proxy records may relate to temperatures, when it comes to forecasting the warming observed in the last 30 years, “the proxies do not predict temperature significantly better than random series generated independently of temperature.”

Also, last month, New Phytologist published a series of papers examining the Amazon rain forest’s vulnerability to drought, following years of increasingly dire predictions that anthropogenic carbon emissions and global warming will kill off Amazon trees. Climatologist Peter Cox, a co-author on four of those papers, told us, “One of the things that turns out to be important is the extent to which tropical forests respond positively to CO2 increases.”

The specifics of that relationship remain “a key uncertainty,” Mr. Cox said, and recent findings have raised more questions than they’ve answered. But the fact that higher CO2 levels can make plants more efficient at using water means that not only might rain forests survive CO2-induced drought better than previously thought, but that carbon emissions overall might even be good for rain forests, up to a point. That’s news, even if it has been little reported.

And while you’ve probably heard (frequently) that this summer appears to be the warmest on record, you may not have been told that an unusually cold spell in the Antarctic brought a chill to southern South America and is responsible for the deaths of six million fish and thousands of alligators, turtles and river dolphins, according to Nature News.

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?

The Wall Street Journal, 2 September 2010