Contraction and Convergence

Once convergence is achieved, all countries' entitlements would continue to decline, following the contraction event necessary for compliance with the United Nations Framework Convention on Climate Change (UNFCCC).

Both the fundamental concept of Contraction and Convergence and the specific formulas advocated by the Global Commons Institute can be adjusted to accommodate a wide range of carbon emission restrictions, from moderate to more stringent measures, depending on the desired level of acceptable risk associated with greenhouse gas concentrations.

However, proponents of Contraction and Convergence assert that the suggested safe level for stabilizing greenhouse gas concentrations is significantly lower than what some propose.

In support of this position, the GCI references their numerical analysis of the overly optimistic assumptions regarding carbon sinks found in the UK Climate Act.

In response to these concerning trends, the Global Commons Institute (GCI) developed Contraction and Convergence (C&C) as a framework to mitigate the adverse effects associated with these disparities.

Following the launch of the Garnaut Review, researchers at Monash University collaborated to publish the first empirical C&C target based on human life expectancies across nations.

[8] However, animations of C&C as 'Climate Justice without Vengeance' show the financial implications of negotiating an 'accelerated convergence', an issue that remains directly relevant to achieving the 'global climate deal' still sought for COP-16 and beyond.

The contraction aspect of C&C was demonstrated by the UK Government Special Representative for Climate Change Sir David King at a debriefing to the International Energy Agency after COP21 in January 2016.