I've begun listening to the Reith Lectures, a series of five weekly presentations by Jeffrey Sachs. I gather from his introduction that the audience is formidable, but so are his ambitions. Sachs feels that we're careening towards a big, thick brick wall, and he's using his Reith lectures to call for a course correction.
Seems like something one might want to hear. BBC 4 Reith Lectures 2007: Sachs and the modern world - by mp3, podcast and rss has directions on how to subscribe. I've got two in iTunes so far.