If the current logjam is to be unblocked, the diplomatic process must find a means of answering this question. The only one so far proposed is called Contraction and Convergence . An increasing number of governments in Europe and the South are signalling that they too see it as the basis of a long-term solution. Contraction refers to the need to reduce global emissions of greenhouse gases to a level that would result in establishing what science regards as a probably tolerable atmospheric concentration. Effectively this would create a global budget of greenhouse gas emissions.
Convergence allocates shares in that budget to the emitting nations on the basis of equity.
This has three components. Second, the current situation whereby allocations are generally proportional to wealth would cease. Third, allocations should converge over time to a position where entitlements are proportional to population. After convergence, all countries would contract their greenhouse gas emissions equally until the necessary contraction limit is reached. No inflation of national budgets in response to rising populations would be permitted after an agreed set date.