The man who helped usher in the environmental movement in the 1960s and '70s has been rethinking his positions on cities, nuclear power, genetic modification and geo-engineering. This talk at the US State Department is a foretaste of his major new book, sure to provoke widespread debate.
http://www.ted.com/talks/stewart_brand_proclaims_4_environmental_heresies.html
or on youtube: http://www.youtube.com/watch?v=TUxwiVFgghE
for those who aren't familiar with him, he was the creator of the 'whole earth catalog' in the late 60s. he's promoting his new book, whole earth discipline – think i'm going to give it a read.