It will be difficult for China and India to live off their own renewables
David Mackay has written in detail about the question 'Can Britain live off its own renewables' in his new book (http://www.withouthotair.com).
The broad answer to this question is that to make an impact renewable energy sources need to be 'country sized' and Britain does not really have 'country sized' areas to devote to energy generation, except perhaps offshore in the Atlantic or in foreign far-flung deserts (and even then there remain formidable technical, political and economic barriers).
Renewable energy sources have a power density around 1-5Watts per square metre. To achieve 5000Watts per person requires1000-5000-square metres per person. To power the entire population requires 50,000-300,000km2 of land (between one fifth and all the land in Britain).
Here are some interesting figures for other countries:
Country__Population__Area (km2)_Density(km-2)_Land pp (m2)
Broadly speaking, this suggests that it will be difficult for China and India to live off their own renewables. Asia is where the future of the global economy (and of future emissions growth) lies. Of course, we see that for US (and in the future for the world in total) this constraint is not as important; but this shouldn't distract us from the need to find a solution that can be adopted in Asia too.
This the view that renewables are the whole answer may be somewhat US centric.
For reasonably local alternatives to coal in USA, China and India it may be that 'renewables' may be only part of the answer. Achieving a cost of electricity lower than coal must be our number one objective, but fundamentally we need an energy source that will suit India and China too.