I know because I have been in similar meetings with many of the same people on this NAS panel. The one I recall was requested by Rep. John Dingell (D- Mich). The meeting was chaired by Eric Barron, from Penn State, a member of the NAS panel. There were about 15 participants, the same number involved in this most recent report. And what “we” said seven years ago looks a lot like what the cademy said last week.
The other dissenter was MIT’s Richard Lindzen. For several hours, we raised a number of objections concerning facts and uncertainties about climate change. Finally Barron announced that if we didn’t stop objecting he was going to stop the meeting.
This is how legitimate scientific dissent was handled!
Did similar things happen with the new report? The two likely dissenters were Lindzen and John Wallace, who chairs the Atmospheric Science Department at the University of Washington. Wallace personally believes we should lower our use of fossil fuels, but scientifically agrees that warming may well be overestimated.
Want proof that groupthink smothered inconvenient dissent? Here are four glaring examples:
1. Lindzen recently published a bombshell paper in the Bulletin of the American Meteorological Society demonstrating there is a huge tropical “thermostat” that regulates planetary warming. This reduces the likely warming in the next century to, at most around 1.6ºC - the low end of the NAS’ range. I find no mention of this paper in the new report.
2. The first sentence of the report talks about how changes in the Earth’s greenhouse effect are “causing surface air temperatures and subsurface ocean temperatures to rise.” How much future warming does this imply? When the observed rise in ocean temperatures is coupled to a predictive climate model, the warming for the next 100 years again comes out at the low end, around 1.4ºC.
3. Almost all of our climate models predict that once human warming starts, it takes place at a constant rate - not an ever-increasing one. Therefore, the warming rate that has been established in recent decades should be the most likely one for the next 100 years, unless all those climate models are wrong. Again, it works out to 1.4ºC.
4. The physics of the greenhouse effect requires that warming begins to damp off if the increase in a greenhouse compound is constant. So the only way that the computer models can predict a constant warming rate for the next 100 years is to assume that the greenhouse gases go in at ever-increasing (exponential) rates.
They are not doing this. Despite the prior beliefs of every atmospheric scientist on the NAS panel, the increase in the last 25 years has been constant, not exponential.
This will tend to reduce, rather than maintain warming in coming decades. A non-exponential increase in greenhouse gases will drive the warming right down to its bottom, or 1.4ºC in this century.
Is there a pattern here? You bet. By far the most consistent interpretation of the facts is that warming is destined to be modest. Further, the atmosphere has already told us that two- thirds of this will take place in the winter, with three-quarters of that in the dead of Siberia, northwestern Canada and Alaska.
The logical question to ask is why the academy didn’t put all of these obvious things together. The answer is simple: The people who put this and the U.N. reports together have been touting big warming for nearly two decades.
Reversing course, and saying anything else would have been self-destructive to the public’s somewhat misplaced faith in science.