For years, despite a steady accumulation of science showing the clear and present dangers of global climate change, efforts toward an effective international response have been at a virtual standstill. The principal reason is that the United States has refused to play. But with Washington now seemingly on a course to enact mandatory limits on US greenhouse gas emissions, it is plausible to begin envisioning a multilateral solution to this quintessentially global challenge. It is, in other words, time to contemplate a new climate change treaty.
The urgency of the task is irrefutable. The Intergovernmental Panel on Climate Change’s latest assessment concluded with 90 percent confidence that human activity is warming the planet and warned of irreversible and potentially catastrophic consequences if emissions continue unabated. Politically as well, the next few years represent a critical window for action. The emission limits assumed by most industrialized countries under the Kyoto Protocol expire in 2012. What momentum the treaty has achieved and the multibillion-dollar carbon market it has spawned may well be lost unless a new agreement can be forged.
detail: http://hir.harvard.edu/articles/1594/1/