This week world leaders have met in New York and Pittsburgh to discuss global warming.  These high-level meetings are aimed at providing a much needed boost to international efforts to secure a strong agreement to address global warming in Copenhagen, Denmark this December.

What emerged from the UN Climate Summit earlier in the week and what are the expected outcomes for the G20 meeting occurring in Pittsburgh?  I travelled to NY on Tuesday and am now in Pittsburgh for the G20 meeting.  I'll answer your questions from Pittsburgh in a live chat on Friday, Sept. 25, at 10 a.m. EDT here on NRDC's Switchboard.