Contraction and Convergence

Description:
With the “Contraction and Convergence” approach, all countries would agree on a global target of, e.g., 450 ppm stable atmospheric concentration of carbon dioxide in the atmosphere. They would also agree on a path of yearly global emissions that lead to that concentration level (contraction). In a second step, the global emission limit for each year would be shared among all countries, including developing countries, so that per-capita emissions converge by a specific date, e.g. 2050 (convergence). The defined targets for each country can be reviewed and revised when new scientific findings require it.

This approach allows for full emissions trading. As all countries participate, those countries with less allowances than needed (e.g. industrialized countries) can buy allowances from other countries that receive excess allowances (e.g. least developed countries). If stringent stabilization levels such as 450 ppmv CO₂ are to be reached, convergence to a per capita emission level below current Non-Annex I average is needed. Consequently, benefits from transfer of resources will be limited to the least developed countries and to the first decades of operation of the system.

This approach has very simple rules. Two major issues need to be negotiated and agreed upon: the target atmospheric concentration of CO₂ and the date, at which the entitlements would converge at equal per capita allocations.

Further Research by:
The Global Commons Institute
RIVM
Ecofys

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