Welcome to European Tribune. It's gone a bit quiet around here these days, but it's still going.
Frank, you've written an impeccable introduction to the subject, and I laud you for it. I actually may copy bits of it, if I get the chance. :)

As for the hesitation if there is a consensus on the thermohaline circulation shutting down: the current consensus is that there is no such thing as a weakening in the thermohaline circulation.

And I'm in a bit of a hurry, so here goes:

  1. the method Bryden used is simply unable to make announcements of a 30% decline, as shown in a Nature publication here;
  2. the first results of the RAPID programme which uses continuous monitoring (unlike Bryden) shows that the variability in the MOC is so large that it invalidates the work of Byrden entirely (and note that Bryden is a co-author), publication abstract here;
  3. I tried to convey that latter message in this diary;
  4. A recent NASA study with different methodologies confirms there is no detected weakening of the conveyor belt, see press release here.

Furthermore, climate models infer, with current projected temperature increases, only an actual slowdown around 2100. And lastly,

RealClimate: Atlantic circulation change summary

Everyone quoted is however agreed on one thing: "the notion that [a future change in the themohaline circulation] may trigger a mini ice age is a myth". The evidence of previous changes for instance at the Younger Dryas or during the 8.2 kyr event is quite strong, and significant coolings were observed particular around the North Atlantic, but even such localised coolings are not predicted to occur if the circulation slows as an effect of global warming.

by Nomad on Thu Dec 9th, 2010 at 06:05:05 AM EST

Others have rated this comment as follows:


Top Diaries

Occasional Series