LibDems save planet, or not

It looks as if there may is some quite bold and interesting stuff in Zero Carbon Britain: taking a global lead, a document put out yesterday by the Liberal Democrats (whose standing in the polls appears to be declining fast).

I haven't read it in full yet. Among things I will want to understand better are:

1. the implications of paragraph 2.1.5, which says:

In the short term, Liberal Democrats would seek to develop a post-2012 framework that allows different countries to participate according to their national circumstances through a ‘multi-stage’ approach. Each country would work towards the 2°C pathway, but the stringency of their commitments will depend on their economic, developmental and environmental circumstances. Industrialised country emissions would be allocated on a per capita basis, whereas developing countries will take on emission limitation targets or intensity targets or no commitments at all, depending on their level of development.

How do they know what the "2°C pathway" is and are they sure it is the right thing to look at (in the light of uncertainty around, e.g., tipping points?). [see footnote A]

If there still is a credible case for saying that there is such a thing as a "2°C pathway", can it be achieved without., e.g., a reduction in Chinese emissions in the "short term", and if so how?

2. the implications of paragraph 2.1.6, which says:

In the medium term, Liberal Democrats would seek an equitable allocation between countries of carbon emissions, with rights to emit allocated on a per capita basis.

What do they mean by "the medium term?"

Footnote A: See, for example, criticism of the 'naive realism' of this approach from David Stainforth et al as reported by Fred Pearce in New Scientist on 14 August, or my note on the Stainforth paper and its implications in The day after back on 8 July.

[P.S. 30 August: see Is a zero-carbon Britain possible? by Leo Hickman.]