The world must avoid backsliding in fighting global warming and work out a “Green New Deal” to fix its twin climate and economic crises, UN Secretary-General Ban Ki-moon said on Thursday. “We must recommit ourselves to the urgency of our cause,” Ban told about 100 environment ministers at Dec. 1-12 UN talks in Poland which are working on a new climate treaty but have been overshadowed by worries about recession. “Yes, the economic crisis is serious,” he said. “Yet when it comes to climate change, the stakes are far higher. The climate crisis affects our potential prosperity and peoples' lives, both now and far into the future.” “There can be no backsliding on our commitments,” he said of efforts to shift from fossil fuels towards renewable energies. Ban urged leadership on the climate from US President-elect Barack Obama and from the European Union. An EU summit ending Friday will try to break the bloc's deadlock on a plan to cut greenhouse gas emissions by a fifth by 2020, compared to 1990 levels.