Agence France-Presse: New York Mayor Michael Bloomberg joined UN chief Ban Ki-moon here Monday in galvanizing world action to roll back climate change, an issue he described as "just as important" as nuclear proliferation and terrorism. "We are damaging our planet. Nobody knows at what rate but at any rate it is not good," Bloomberg told reporters after addressing a UN General Assembly debate on the impact of global warming. "We have to do something about it and we have to …