Bertrand Russel Annhilates Planet

In the video:

Global Warming Alarmist Calls For Eco-Gulags To Re-Educate Climate Deniers - Alex Jones Tv 1/2
http://www.youtube.com/thealexjoneschannel#p/u/41/j5FipVfEWGw

At about 5mins30secs he states: "Bertrand Russell, he said wipe out major cities to redesign the planet."

I'd like to see the source of that quote or paraphrase. Anyone?

thanks

Ebook: "Impact of Science on Society" by Bertrand Russell
http://www.scribd.com/doc/30042334/The-Impact-of-Science-on-Society-by-Bertrand-Russell