Thomas Homer-Dixon, Director of the Trudeau Centre for the Study of Peace and Conflict at the University of Toronto, recently published a book, The Upside of Down, in which he delineates a set of "techtonic stresses," including the scarcity of oil and global climate change, that could cause "a catastrophic breakdown of national and global order" but also "open up extraordinary opportunities for creative, bold reform of our societies." I recently spoke to Thomas Homer-Dixon about his book, the complexity of an effective response to global climate change, and multilateralism.