Blue and Green: As recently as the 1990s Bogotá, the capital of Colombia, was associated more with violence, drug wars and murder than sustainability. Foreigners saw the city as one the worlds most dangerous places to visit and cocaine was one of its most famous exports. Its journey towards redemption gathered momentum in 1998, with the appointment of Enrique Pealosa as mayor. As well as cleaning up the capitals image, one of Pealosas priorities was to make rapid improvements to mobility. While most of us...