Bloomberg: Global warming certainly has one politician's attention. In his weekly address President Obama cited climate change as Earth's single biggest threat. Today, theres no greater threat to our planet than climate change, Obama said. Climate change can no longer be denied or ignored. Obama pointed out that 2014 was the warmest year on record, and that 14 of the 15 hottest years measured have occurred since the start of this century. The first three months of 2015 have been the hottest start...