Climate OptiOns for the Long term (COOL) - Global Dialogue Synthesis Report

It took as its 20020621 point a stabilisation of CO₂ concentrations at 450 ppmv (or 550 CO₂ equivalent) around 2100, translated into a emission reduction of 15-25% by 2050 compared to 1990 levels. It was found that such an emission reduction is technically feasible at limited economic costs provided that the world develops in an economically and politically favourable way (open world) and major social and institutional barriers can be overcome. It requires an early involvement of developing countries in global emission control and the establishment of a global emission trading system to reduce emissions in a cost-effective way. This seems to require the development of a comprehensive international climate regime as an ad hoc incremental evolution of the climate regime is unlikely to keep the option of stabilising CO₂ concentrations at 450 open. It is crucially important to account for the large inertia in the both natural and human systems. Near-term climate policymaking needs to take a long-term perspective either by formulating provisional long-term climate targets, or by systematically reflecting on long-term implications of near-term decision making. Moreover, the project has resulted in a list of desirable short-term actions.