NUSA DUA, Indonesia (AFP) — World climate negotiators set a 2009 deadline Saturday for a landmark treaty to fight global warming after two weeks of intense haggling led to a climbdown by an isolated United States. UN Secretary General Ban Ki-moon, who flew to the Indonesian island of Bali for a late appeal for flexibility, praised the deal as a "pivotal first step" to confront climate change, "the defining challenge of our time." Following gruelling all-night talks, the conference of 190 nations finally launched a process to negotiate a new treaty for when the UN Kyoto Protocol's commitments expire in...