Integrated Assessment of Long-term Climate Policies: Part 2 – Model Results and Uncertainty Analysis.

An integrated assessment model (IAM) is applied to explore options for long-term climate policy by identifying permitted emission corridors. The options are determined under various assumptions about constraints related to acceptable impacts of climate change in terms of alterations induced in natural ecosystems in protected areas and about acceptable mitigation costs, burden sharing principles, and implementation flexibility. The results show that about 25% of the protected areas worldwide will witness ecosystem transformation in the next century even if the costs of emission reduction are allowed to reach 2% of per-capita consumption. An uncertainty analysis surveys the implications of modifying selected key model variables on the existence and shape of the emission corridors. Within plausible ranges of parameter variations, the emission corridor turns out to be rather sensitive to impact constraints, climatic constraints like the magnitude and rate of the global mean temperature increase, and to aerosol emission scenarios. [ABSTRACT FROM AUTHOR]