The United Nations Climate Change Conference in Copenhagen, which begins Dec. 6, is being hailed as the biggest international move on global warming since the Kyoto Treaty. But hopes aren’t too high for this round of talks, largely because of the high cost of technologies needed to reduce carbon dioxide emissions. Officials say that without a renewed effort to cut emissions, world temperatures may rise by up to 7.2 degrees by 2100, which would cause a host of environmental and health problems—even natural disasters. Yvo de Boer of the U.N. says ideal takeaways from the conference would be emission goals for industrialized nations, emissions-free energy goals for developing nations, promises of technology from industrialized nations to make progress possible in the developing world, and an agreement on how to proceed. But both industrialized and developing nations are skeptical of the economic ramifications of a new set of emissions goals. “The issue is not whether you are for or against climate change, but rather how much you are willing to sacrifice to slow climate change,” says Yale economist Robert Mendelsohn. “If we sought a moderate policy that will eventually lead to substantial reductions of greenhouse gases, it is very likely one could get global agreement in Copenhagen."