I know Rachel’s already posted about Gavin’s TED talk, but it’s worth posting again. I thought I might also highlight the slides from another talk that Gavin gave at the Royal Society. You can also listen to the talk.
What’s interesting about Gavin’s Royal Society talk, is that it’s about using Global Circulation Models (Global Climate Models – GCMs) to model our past climate, in particular the mid-Holocene, the Last Glacial Maximum (LGM), and the last Millenium. It also probably has one of the best quotes on this topic that I’ve encountered
If we had observations of the future, we obviously would trust them more than models, but unfortunately …… observations of the future are not available at this time. (Knutson & Tuleya – 2005).
I don’t want to say too much about this as it’s not something I’m that familiar with, but as I understand it these are the same models that are being used to understand how different emissions pathways (RCPs) will influence our future climate. This type of modelling therefore seems useful as it’s another way of testing the models. You can also use it as another estimate of climate sensitivity, although I’m unclear as to whether or not this can be regarded as an independent estimate. It does, however, seem to give ECS estimates that are consistent with other methods – as shown in the figure below, which I’ve taken from Gavin’s talk slides.
Anyway, that’s all I was going to say. I’m sure there are some regular commenters who understand the significance of the paleo-model comparisons better than I do. The main point of this post was simply a chance to highlight Gavin’s excellent TED talk, which you can view below.