Cross-published on the Live Earth blog. More than 190 countries will gather at the UN Climate Change Conference this December 7-18 in Copenhagen to determine the environmental fate of our planet (see the Guardian’s ongoing coverage for baseline facts). With less than 40 days remaining before the Copenhagen conference, a new effort –Hopenhagen — seeks to unite citizens across the world in political action. The Hopenhagen site features a petition, which will be delivered to the conference. The goal: Get participating countries to seal the deal and sign an effective climate pact. More than 340,000 people have already signed the petition. There is a mandatory Hopenhagen Facebook fan page. In one of the more interesting Facebook applications I have seen …