Today's podcast guest is bioecologist and ecological economist Dr. William Rees, professor emeritus of the University of British Columbia’s School of Community and Regional Planning. Rees is best known for his development of the "ecological footprint" concept as a way to measure the demand a particular population places on the environmental resources it needs to survive.

Since the beginning of modern agriculture (around 1800), human activity has increased demand on planetary resources at an exponential rate. More energy has been expended -- and more resources consumed -- in the past 40 years than in all of human existence beforehand. That is placing a greater and greater strain on ecosystems that are now dangerously depleted.

Click the play button below to listen to Chris' interview with Dr. William Rees (67m:45s).

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