PlanetEarth: ue Nelson:This time in the Planet Earth Podcast, the untapped energy in big cities and how a new map can reveal its potential. I'm Sue Nelson and I'm in Leeds on a bright and cloudy day with a hint of grey revealing the showers that may well appear later. In fact it is fair to say that Britain is well known for its weather - it can be sunny, wet and windy within the space of an hour, sometimes, and discussing the weather has almost become a national pastime, but researchers here are more interested...