How to set a stabilisation target

David’s right below about the lack of specifics on stabilisation levels.  But it’s worth remembering the lessons of Ken Livingstone’s Congestion Charge in London: start with lax targets, then ratchet them up later, after people have got used to the principle of having them.

What would this mean in the global climate policy context?  Agree the principle of having a target; set it as high as we like (1,000ppm, anyone?) – and then build in triennial or quinquennial review by policymakers.

Then, when the damages really start stacking up and a sharp intake of breath is heard from electorates and policymakers, we can avoid the usual kneejerk policy responses that tend to follow scary events; and instead, simply ratchet the target down to a credible figure, like 450.

In the meantime – presto! – the policymakers who agreed the principle of a stabilisation target in the first place will have moved on to greater things (a job as a Middle East peace envoy, perhaps), leaving the heavy lifting to their successors.