Paris - More than 50 nations are attending a world-first conference on phasing out fossil fuels in Colombia next week as the Iran war underscores how dependent countries remain on planet-heating coal, oil and gas.Ministers arrive in the Caribbean city of Santa Marta against a backdrop of wartime fuel shortages, soaring prices and a scramble for energy security in what the International Energy Agency has called the biggest oil supply shock ever.The gathering was born out of frustration with consensus-based United Nations climate talks, where efforts to negotiate a fossil fuel exit strategy have stalled.