Toronto Star: Canada is backing strong warnings from U.S. President Barack Obama about the need for nations to act on the urgent, growing threat of climate change. In an address to a business audience here Wednesday, Obama laid out the threat of climate change, saying the patterns and the science don't lie and that no nation is immune to the consequences. Temperatures and sea levels are rising, ice caps are melting, storms are strengthening, he said. If we want to prevent the worst effects of climate...