The World Summit on Sustainable Development (WSSD) is likely to see the Kyoto Protocol finally coming into force. While this will be a moment to celebrate, there is no cause to be complacent. Although a step in the right direction, the Kyoto Protocol was always an imperfect agreement and has been made all the more imperfect by the fact that the world's largest polluter has decided to stay out of the consensus and those who have agreed to join have demanded and received changes that have weakened the Protocol considerably. It is time, therefore, to begin thinking about the shape of the global climate regime in its post-Kyoto phase.