Gerbrand Komen 7 December 2011:
(with two clickable links added on 12. December 2011)
On 31 August 2011 Fred Singer gave a lecture at the Royal Netherlands Meteorological Institute (KNMI). This lecture was followed by a discussion on two propositions, which had been proposed to Dr Singer beforehand (on 25 July 2011; see schedule):
- A Climate scientists must communicate uncertainties and their consequences.
- B None of current climate models overcome chaotic uncertainty
Proposition B was one of the conclusions of Dr. Singer in his lecture. In essence, Sybren Drijfhout argued that this proposition was incorrect, because:
- It was based on a case study which did not allow generalization.
- KNMI had made runs with a ‘current climate model’ which actually did overcome ‘chaotic uncertainty’ (i.e. noise due to variability).
In his reaction on 31 August Dr. Singer ignored proposition A, and he did not comment on proposition B, saying that he first wanted to study the arguments of Dr. Drijfhout.
On 17 October 2011 I initiated an e-mail exchange, hoping to arrive at a joint statement. Initially there was some encouraging convergence. However, the final mails in this exchange, in December 2011, made further convergence unlikely.
I believe it is important that I present my conclusions:
- Both Singer and van den Hurk endorse proposition A.
- Drijfhout refuted Singer’s conclusion (proposition B). Singer’s reaction is inadequate.
(Adapted with permission from