Yesterday wrapped up the C40 Large Cities Climate Summit here in NYC. London hosted the first summit in 2005. C40 Cities is made up of a group of the world's largest cities committed to tackling climate change. Cities are responsible for three-quarters of the world’s energy consumption, so we can have a major impact when acting together to improve our effect on global warming.

For more info, check out C40 Cities. And read Mayor Bloomberg’s keynote address to the summit here.