Contraction and Convergence

Contraction and convergence describes a concept of climate change, which consists of two dimensions: contraction refers to the necessary reduction of greenhouse gas emissions to curb global warming. Convergence means, just divide the total amount of emissions decline to all people.

The convergence idea assumes that every person the same carbon dioxide emission amount is granted. As the world's population, currently about 7 billion people (2011) will increase to up to 10 billion people in 2100, while the global CO2 emissions are to be reduced, it follows that also the personal CO2 budget over time must decrease.

The concept was developed in 1990 by the Global Commons Institute in three years' work. 2007, it was first discussed in the German-speaking world under the name Carbon justice of the general public.

Meanwhile, the scope of the concept has been expanded not only greenhouse gas emissions are to be reduced and unified world, but the entire nature of man consumption. This proposal is formulated, inter alia, published by the Wuppertal Institute study Fair Future. WWF developed the Living Planet Report for the entire ecological " footprint" of mankind a similar model for the future, which was designated S & S (Shrink and Share ) to avoid confusion.

Been criticized, among others, the concept of economist Nicholas Stern, who at the UN Climate Conference in Bali in 2007 called it a "spectacular weak form of justice." Reason for this is that when adopted achieving the convergence, the industrialized countries have historically been expelled multiples of greenhouse gases as developing countries.

A further development of the concept, the historical emissions ( responsibility) and current efficiency ( Capacities ) takes the States in a multi - indicators model, is the model of the Greenhouse Development Rights ( GDRs ) of the Institute Eco - Equity, sponsored by the Heinrich Böll Foundation, and ChristianAid.