Cristian Retamal, Chile's former negotiator at the annual UN climate talks, hopes this week's conference in Colombia will lead to the start of a new global political movement. Retamal is in Colombia's northern coastal city of Santa Marta, where representatives from more than 50 countries are meeting for the first-ever conference on transitioning away from the fossil fuels that are heating the planet. They aim to come up with a practical, equitable plan to help the world reduce its dependence on coal, oil and natural gas , and identify which legal, economic and social measures are needed to do so. The conference, taking place from April 24 to 29, was created amid frustration at last year’s UN climate conference . Despite support from a broad coalition of more than 80 countries, the talks failed to nail a binding mandate to phase out fossil fuels, due to a veto led by petrostates like Russia and Saudi Arabia .…