Thanks. I will have to get 'The Rational Optimist'. Matt Ridley's book 'Nature via Nurture' impacted me a lot when it first came out.

The online course 'Physics for Future Presidents' taught me a lot about how to evaluate energy sources. I would recommend it to anyone interested in learning the physics concepts behind many hotly debated areas, whom currently has little knowledge or exposure in this area.

As far as Matt Ridley's writing, can you speak to whether these are the same arguments: http://online.wsj.com/article/SB1000142405274870342120457632... ?

Summarized, Ridley argues here that the "renewable/non-renewable" distinction is quantitative (not qualitative), and that renewable energy harvesting devices are built from non-renewable materials.

Some of the arguments in that article are repeated in the book, but it's not the main thrust of the chapter I was referring to. I'm afraid I gave the book to my brother after I read it, so I can't give you an authoritative summary of the arguments in the book. As best as I can recall, the argument was renewables generally have such low power density (W/m^2) and high energy cost ($/J) that they are unlikely to be an effective solution to climate change, should climate change be as severe as we fear it might be. (Ridley is not a climate change denier, but he does think scientists' worst fears are exaggerated.

Here's an audio interview with Ridley that might cover some of the same stuff in the book: http://www.econtalk.org/archives/2010/10/ridley_on_trade.htm...