Regional costs and benefits of alternative post-Kyoto climate regimes: Comparison of variants of the Multi-stage and Per Capita Convergence regimes

For the Annex I regions, reduction targets are more dependent on the stabilisation level than on the type of regime chosen. In 2025, most regimes show emissions reductions for Annex I regions of 25-50% compared to their 1990 levels. 

For the non-Annex I regions, the results are generally more differentiated and differ strongly per regime and in time. Under all regimes, early participation of (major) non-Annex I regions is needed. Four groups of regions with similar efforts can be identified with respect to their abatement costs as percentage of GDP. 

The study also found that climate policies can induce significant co-benefits, such as a decrease in the sulphur and nitrogen oxide emissions. 

Overall, the analysis shows that in evaluating the implications of various regimes, it is not sufficient to evaluate only the allocation of the emissions compared to baseline. Abatement costs and changes in energy trade will also have to be assessed. The gains from participating in global-emissions trading and realising reduced air pollution damage and/or abatement costs can make early participation of (large) developing countries in global GHG control possible at low costs or even net gains. However, the level and form of commitment will have to be well chosen - and not be too strict - to balance economic risks and political viability.