In case you missed it: "Smoking gun" email from BBC's Jonathan Renouf to Keith Briffa: "Your essential job is to "prove" to Paul that what we're experiencing now is NOT just another of those natural fluctuations we've seen in the past"

Email 1683

date: Wed, 7 Sep 2005 13:56:57 +0100 from: "Jonathan Renouf" subject: Final thoughts to: "Keith Briffa"

Hi Keith, Good to talk to you this morning. Just a few thoughts to reiterate what we're hoping to get out of filming tomorrow. 1) Your interview appears at a crucial point in the film. Up until now our presenter (Paul Rose, he'll be there tomorrow) has followed two conflicting thoughts. On the one hand he's understood that the world is currently getting warmer. But on the other he's discovered lots of historical stories (the Bronze Age, the MWP, the LIA) which tell him that climate changes naturally all the time. In trying to resolve this paradox he's come across this thing called the hockey stick curve, and he's come to you to explain it to him.

2) Your essential job is to "prove" to Paul that what we're experiencing now is NOT just another of those natural fluctuations we've seen in the past. The hockey stick curve is a crucial piece of evidence because it shows how abnormal the present period is - the present warming is unprecedented in speed and amplitude, something like that. This is a very big moment in the film when Paul is finally convinced of the reality of man made global warming.

3) The hockey stick curve shows that what Paul thought were big climate events (the Bronze Age maximum, the MWP, the LIA) actually when looked at in a global context weren't quite as dramatic as he thought. They're there, but they are nothing like as sudden or big.

4) Paul can question you on things like: How reliable is the hockey stick curve? How do you work out past climate (cue for you to talk about proxies)? What drives all the "natural" fluctations in climate (this can be answered in very broad terms eg it's down to changes in the sun's output, volcanoes etc)

5) In terms of filming my first choice is to do it as a projection in Zicer, where you show the Mann curve, then flick up as many other ones as you think are important (within reason!) and elaborate the point that what's happening now is unprecedented compared to these historic records. In my ideal world, you walk right up to the projector image and point things out on the screen, with parts of the projected image falling on your heads and shoulders. Stills of tree rings or anything else climate related eg ice cores, corals, would also work as powerpoints, because you could talk about them as egs of proxies.

Hopefully this makes it clear what I'm trying to achieve. Look forward to tomorrow. All best Jonathan [Renouf, Series Producer, BBC]

Hat tip: M. Hulme (as far as I know, this is NOT warmist Mike Hulme)