Roger Pielke Jr:
There is a new paper out by Brysse et al. in Global Environmental Change (here $) which includes as co-authors Naomi Oreskes (author of Merchants of Doubt) and Michael Oppenheimer (long-time IPCC contributor and a contributing lead author for the AR5). The authors report a remarkable finding — they have identified a shortcut to divining the true state of knowledge of the science of climate change.
As the authors’ explain:
Evidence from recent analyses suggests that scientists, particularly acting in the context of large assessments, may have underestimated the magnitude and rate of expected impacts of anthropogenic climate change. We suggest that this underestimation reflects a systematic bias, which we label “erring on the side of least drama (ESLD)”.
What ESLD therefore means is that when scientists make a claim about climate change, particularly via the IPCC and other assessments, the presence of a systematic bias means that the odds are that things are really much, much worse. ESLD therefore offers a short cut to anticipating where climate science is headed.
An important reason for this bias, the authors assert, is of course none other than those evil skeptics:
[O]ne possible reason why scientists may have underestimated the threat of anthropogenic warming is the fear that if they don’t, they will be accused by contrarians (as was Schneider) of being alarmist fear-mongers. That is to say, pressure from skeptics and contrarians and the risk of being accused of alarmism may have caused scientists to understate their results.
Not only is the accusation of a systematic bias an insult to the integrity of practicing scientists, but the entire paper is built on an empirical foundation that does not touch the ground.
Let’s take a closer look at the data claimed to support the ESLD hypothesis. The paper examines literature on IPCC predictions for temperature and sea level, hurricanes, and the role of greenhouse gases from permafrost melting in climate models.
- It finds that sea level is running well below the 1990 IPCC prediction and above the 1995 and 2001 predictions (if anyone can make sense of 2007 IPCC predictions then you get a bonus point).
- It finds that observed temperature increases are consistent with the predictions of all 4 IPCC assessments.
- It finds that the IPCC accurately reflects the community understanding on hurricanes.
- It finds that peramfrost melting is not included in climate models, representing ” potentially profound bias in the climate projections—not toward overestimation of climate change, but toward its underestimation.”
- They also cite Arctic sea ice and some science on rainfall.
So here is my tally: 3 sea level predictions + 4 temperature predictions + AR4 hurricanes + permafrost + rainfall + Arctic sea ice = 9 data points. Of these 9, the scientific community has been accurate on 5, overestimated the near term evolution in 1 case and underestimated in 3. Are you convinced of ESLD?
