Contraction and Convergence
"Contraction & Convergence (C&C) offers an intellectual framework for reaching international agreement on reducing greenhouse gas emissions. C&C was developed in the 1990s by the Aubrey Meyer of the UK-based Global Commons Institute.
Contraction describes a path of emissions reductions to reach a safe level of greenhouse gases in the atmosphere. Convergence describes a narrowing of the current emissions gap among the world's peoples — to gradually achieve equitable per capita shares of global greenhouse gas production." (http://www.peopleandplace.net/our_compass/2009/3/25/contraction_and_convergence)