Obama: Climate action an economic and security 'imperative'

US President Barack Obama said Tuesday global warming posed economic and security risks that had to be tackled immediately, but insisted the climate problem could be solved. If global warming continues, "then before long we are going to have to devote more and more of our economic and military resources not to growing opportunity for our people but to adapting to the various consequences of a changing planet," Obama said. "Climate change is a massive problem, it's a generational problem," Obama