My weblog of October 28 stirred up quite some dust here in Holland. The Director-in-chief of KNMI was upset enough to send me an e-mail (the first ever!) explaining the official position of his institute. He wrote that KNMI supports the choice of 130 cm of sea-level rise as a worst-case estimate based on the worst-case scenario of IPCC. I responded by writing that I felt it was his duty to declare in public that Professors Kabat and Vellinga had made statements that go far beyond this extreme scenario, and were badly damaging legitimate concerns about climate change that way. He did not respond to that. I also sent him a draft of this second weblog, giving him the chance to respond or to prepare a weblog himself. He didn’t react to that either.
In the meantime, my mailbox was inundated. One Dutch climate scientist, who wishes to remain anonymous because of possible loss of job security, sent me the letter reproduced below. I need not comment on the Climate of Fear apparently prevailing in the Dutch climate research community.
My respondent wrote: “I recently learned that there has been some debate about the contribution of KNMI, the Royal Netherlands Meteorological Institute, to the report by the Delta Commission. In this report, the Commission gives an estimate for the sea-level rise in the Netherlands in a “worst-case” scenario. Following the presentation of the report, two members of the Commission, Pavel Kabat and Pier Vellinga, stated that the sea level rise in this scenario - 130 cm rise in 2100 - is actually not a worst-case scenario, but a very likely one. This is a bit awkward, as you would think that everyone contributing to the report has agreed that this is actually a plausible-yet-very-unlikely scenario, and that by definition it cannot get worse than the worst possible case.”
“In a magazine interview, Pavel Kabat said: “I think we can easily reach or exceed 130 cm. We have given a cautious estimate of ice-cap meltdown. A new British study presents even higher figures.” In an official lecture at Wageningen University, Pier Vellinga said: “It is very likely that we have to act within thirty years or less if we wish to prevent the Earth from warming up six to ten degrees in the next two centuries and the sea level from rising six meters or more.”
“Clearly, Kabat and Vellinga claim that the danger far exceeds the conclusions in the report to which they themselves have contributed. Normally you would expect that this would provoke an angry response from the other contributors. However, the Dutch climate research community has remained conspicuously silent. I would be willing to respect KNMI’s choice to remain silent, but only if everyone involved agrees that 130 cm is indeed an upper limit, based on a culmination of unfavorable scenarios. On its website, KNMI states that the policy with regard to coastal defense for the coming period continues to be based on the KNMI-2006 scenarios. KNMI agrees on 130 cm as a plausible upper limit, but will adjust that number in the light of new observational evidence.”
“But how on earth are you going to validate the estimate of an upper limit? I would love to have explained in detail how we are going to establish, based on observations, whether or not the 130 cm is plausible. What methods, which observations, which time frames are required? By definition, validating something that is only a possibility is not possible beforehand. Since it is only a possibility it might not even occur.”
“To complicate matters further, recent scientific publications show that we are not even capable of determining sea level rise during the last 5 years (2003-2007), while this is a period with by far the best available observations (Willis, JGR-oceans, 2008; Wunsch, J. Climate, 2008). Estimates range from zero rise to 3 mm/year; it is suggested in the literature that 3 mm might be an overestimation. These findings were recently presented at a KNMI seminar. Yet no mention of these new findings anywhere.”
“KNMI could adopt another attitude. Take the KNMI or IPCC scenarios as starting point, and make very clear that these are the most likely results. Then take the scenario from the Delta-report - the background report indicates that even for the worst-case scenario the possibility exists of zero sea level rise despite the 6 degrees warming if all conditions are favorable - and draw the conclusion that it is simply not possible to derive anything meaningful from the worst-case scenario. It would have been possible that the worst-case scenario would have narrowed down uncertainties, but alas, that is not the case. This fact - the large uncertainty margin - could just as well be used to develop policy, a policy that can be adapted according to the progress of our knowledge and understanding. There are various possibilities for such a policy and there are plenty of scientists and researchers who promote developing these ideas.”
“I feel I have an obligation to warn society about people like Vellinga. I consider him dangerous because of his alarmism, his unfounded speculations about climate change, and his misrepresentation of the findings in the Delta-report. Also, it would be good for the reputation of KNMI if it would adopt a more critical attitude. If KNMI does not accept and promote the idea that in the end it is all about truth, finding the truth, being objective and letting scientists be scientists, discussing and disagreeing with one another, then KNMI cannot be considered an independent scientific institute anymore. Independence and authenticity, that is what separates scientists from politicians or the common people.”
That was my respondent’s reaction to the official position of KNMI. Like him, I am reluctantly willing to go along with 130 cm as an upper limit obtained by an accumulation of extreme assumptions, but only if no statements beyond that extremely unlikely scenario are tolerated. KNMI is in danger of losing its reputation as an authoritative scientific institution. As a retired KNMI research chief, I feel both ashamed and dismayed.