AlJazeeraEnglish | 29 November 2010 | Experts believe 2010's severe weather changes hit the poorest communities around the world hardest. This is further evidence of the devastating effects of global warming. The Cancun UN climate summit will seek a commitment to keep global carbon dioxide emissions low, after the failure in the last climate meeting in Copenhagen. Though the challenges remain the same there are those who question whether the Cancun summit can combine mapping out a global vision on how to deal with climate change along with finding ways to pay for it. Al Jazeera's Mariana Sanchez reports from Mexico City.