Agence France-Presse: President Barack Obama will seek to galvanize international support in the fight against climate change on Tuesday when he addresses the United Nations, with time running out on his hopes of leaving a lasting environmental legacy. Obama has warned that failure to act on climate change would be a "betrayal" of future generations, but faced with a Congress reluctant to even limit greenhouse gas emissions -- let alone ratify an international agreement -- his options appear limited. Tuesday`s climate...