International Herald Tribune: Representatives from more than 160 countries began formal negotiations here yesterday on a treaty to mitigate climate change, with the secretary general of the United Nations, Ban Ki-moon, urging governments to help in "saving the planet." more stories like thisThe talks, which are scheduled to conclude at the end of 2009, come three months after a rancorous meeting in Indonesia that exposed deep fissures in how countries plan to battle global warming. "Saving …