Dear Aubrey

With pleasure I support your initiative.

With all the best wishes

Markus Vogt

Contraction and convergence

One of the most interesting concepts for a common contract on CO2 justice is currently being debated under the title contraction and convergence (C&C). This combines a contract which fixes an upper limit for global CO2 emissions (contraction) with a gradual introduction of a distribution of emission rights according to egalitarian principles (convergence).

Basis for the fixing of a global upper limit is consensus within society about level of the ecological risk that can be justified. However, ecological risks can neither be calculated from a natural threshold nor predicted with any certainty. And yet there is a broadly accepted consensus within current political negotiations that global warming by 2°C or a 450ppm concentration of CO2 can be taken as just such a threshold. 56 Following the principle of risk avoidance the C&C concept uses this rather low upper limit, although climate researchers disagree as to whether it is still a realistic goal.

For the process of negotiating CO2 reduction rates the C&C concept accepts the historical distribution as the basis for proportionally-fixed contributions (grandfathering). This is however only the starting point for what then becomes a process with fixed and binding stages, aimed at gradually drawing closer to an egalitarian pro capita distribution of emission rights. The grandfathering principle eases the transition for countries with a high level of emissions. It can be justified ethically as property protection and pragmatism.

“And while a convergence that begins with grandfathering can be ethically justified as easing the transition on high-emitting countries, consistency would seem to demand a similar ‘back end’ mechanism by which emission in low-emitting countries would be allowed to temporarily overshoot the global average, if, that is, ‘easing the transition’ is indeed the justification for initial grandfathering.”

The post-Kyoto negotiations have not yet reached a decision between the two types of model described here as contraction and convergence and responsibility and capacity. C&C offers a realistic opportunity for strategic north-south alliances and is currently enjoying growing support, for example in Great Britain.
Climate Justice - An ethical analysis of the conflicts, rights and incentives surrounding CO2
by Prof. Dr. Markus Vogt, LMU Munich







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