George Monbiot does a good job in explaining the implications of work by Susan Solomon et al, Myles Allen et al, and Malte Meinhausen, although his 'rough sum' showing that we cannot afford to burn already known reserves was, I think, already old news when the Stern report articulated it some years ago, and the optimism at the end of his piece seems a bit strained.
As he rightly says, the 10:10 campaign will be on the wrong track if it allows business the get-out clause of reduced emissions intensity.
In the event that Britain does achieve an absolute reduction of 10% in its emissions within a year the impact on the global emissions trajectory will be very modest, and in any case few rapidly growing, up-and-coming countries will see Britain as a model.
Within Britain, if one were being hugely optimistic, he might imagine 20% of households and major players in the economy 'taking a [temperance] pledge' to reduce their carbon footprint by 10%: a 2% reduction in UK emissions that has no guarantee of being sustainable. Only a massive investment programme, most probably led by government, would do the job...or an economic meltdown on the scale of the old German Democratic Republic.
In 2007 I spent some time helping to convince the editor of the UN Human Development Report (for which I was contributing a background paper and some advice) that the 2007 report should endorse a 450ppm ceiling. At the time such the number was considered to be the very edge of what the mainstream would accept as rhetoric. My own view was that the sensible -- although obviously unachievable -- target should be way below 350 (something that Pachauri recently endorsed, but only as a human being).
I'm finding it increasingly hard to be optimistic these days. Over a game of chess I recently told Paul Kingsnorth that I was more sympathetic to the position outlined by George Monbiot in their recent exchange than I was to his: the consequences of giving up on 'civilisation' just seem too horrible to contemplate.
But whatever one's rhetoric of choice, the actual behaviour of industrial civilisation is more like the character Harry Angel played by Mickey Rourke in the movie Angel Heart. Or as it goes elsewhere, "I weep for you", the Walrus said, "I deeply sympathise."
Of course, it would be nice if, as is the case in so many predictions about the future, I were plain wrong. Perhaps the future isn't as bad as it used to be!