France's President Francois Hollande warned Tuesday that the world is headed for an environmental catastrophe. The French leader said that world leader must begin "serious work" on renewable energy and other eco-friendly initiatives. Speaking at the Future Energy Summit in Abu Dhabi, which brought together policymakers and experts in green technology, Hollande urged for more investments in renewable energy and efforts to renovate older cities for greater energy efficiency. He added that he hoped Paris could host an international climate conference in 2015. Follow Ynetnews on Facebook and Twitter