Diplomats from 192 nations are attending the U.N. climate-change conference in Copenhagen, which opened on Monday, in what may be the world's last, best chance to protect the world from a global-warming calamity. The conference is the culmination of two years of negotiations, and the first week of the two-week gathering will focus on refining the text of a draft treaty. According to conference president Connie Hedegaard, the key will be finding a way to funnel public and private funds to poor countries for years to come to help them combat climate change. President Obama will be one of the 110 heads of state to attend the last few days of the conference. His trip suggests that an agreement is closer.