Climate change and the new world economy : implications for the nature and timing of policy responses

Abstract The world has recently moved to a new economic growth path, driven by the rapid growth of developing country economies. How this new path affects the vulnerability of key biophysical systems and its resulting policy implications are assessed using a risk-based approach. Greenhouse gas emissions based on current policies are projected to 2030, with aggressive reductions from 2030 to 2100. Probabilities for global mean temperature in 2100 are applied to damage functions for four key vulnerabilities. Five conclusions are reached. CO 2 emissions grow by 3.1% per annum over 2004–2030. Atmospheric CO 2 concentration levels >900 ppm CO 2 -e and warming of 2.2–4.7 °C are attained by 2100. The four key vulnerabilities face a very high risk of adverse outcomes. The current policy mix cannot adequately manage these risks, which can be reduced but not eliminated by early global action. Furthermore, the Intergovernmental on Panel Change's (IPCC) Special Report for Emission Scenarios (SRES) no longer provide a reliable tool for medium-term analysis in the new economy. Measures to reduce global fossil fuel consumption, accelerate the diffusion of existing non-fossil fuel technologies and to hasten the development of new technologies are urgently needed.