Agence France-Presse: Senator John Kerry vowed Tuesday to overcome the odds and approve US action to curb carbon emissions, raising the specter of millions of refugees unless climate change is addressed. While offering no timetable, the ally of President Barack Obama rejected predictions that Senate approval of a climate bill — which would offer a boon to troubled talks on a new global treaty — had become politically impossible. “I’m excited. I know that’s completely contrary to any conventional …