And, year after year, those reports are criticized for being too conservative.
Over the weekend, the BBC reported on a new push for an international investment in computers capable of modeling the complex evolution of the global climate. Climate scientists, the BBC charged, had “failed to predict flood and heat intensity” — a failure exposed in the recent heat wave in the United States and Canada and in the recent flooding in Europe. The article included the above indictment of the IPCC’s estimates.
“The IPCC’s reports tend to be both conservative and consensus,” Bill McGuire, emeritus professor at University College London, told the network. “They’re conservative, because insufficient attention has been given to the importance of tipping points, feedback loops and outlier predictions; consensus, because more extreme scenarios have tended to be marginalized.”
Speaking to Axios, Lawrence Berkeley National Laboratory’s Michael Wehner similarly argued that climate scientists had erred in favor of less extreme predictions, in part out of concern that they might seem alarmist. But for anyone who has been tracking the IPCC’s reports over time, that the effects of climate change might extend beyond the projected estimates was always clear.
In 2003, John Houghton, then the IPCC co-chair, conceded that some people believed the temperature projections included in the group’s first report — released in 1991 and which informed the international Kyoto climate accord — showed that “the IPCC was far too conservative and should have been bolder” even then. In 2005, he adopted that position himself, telling a Senate committee that “IPCC reports have consistently proved to be too conservative” in their estimates.