Canada is emerging as the largest supplier of energy to the United States. It's electricity, natural gas and oil are all being shipped to America, but environmentalists there and here say it's coming with a hefty price tag.
Animal manure on industrial farms can wreak environmental havoc. At the University of Guelph in Ontario, microbiologist Cecil Forsberg has found a solution to the problem. He genetically modified pigs to produce low-phosphorous manure.
As climate change cuts the flow of the Colorado river, drought-like conditions in the American Southwest may become the norm.