Common But Differentiated Responsibilities

Common But Differentiated Responsibilities (CBDR) is a principle that was formalized in the United Nations Framework Convention on Climate Change (UNFCCC) of Earth Summit in Rio de Janeiro, 1992. The CBDR principle is mentioned in UNFCCC article 3 paragraph 1.., and article 4 paragraph 1. It was the first international legal instrument to address climate change and the most comprehensive international attempt to address negative impacts to global environment. The CBDR principle acknowledges that all states have shared obligation to address environmental destruction but denies equal responsibility of all states with regard to environmental protection.

In the Earth Summit, states acknowledged disparity of economic development between developed and developing countries. Industrialization proceeded in developed countries much earlier than it did in developing countries. CBDR is based on the relationship between industrialization and climate change. The more industrialized a country is, the more likely that it has contributed to climate change. States came to an agreement that developed countries contributed more to environmental degradation and should have greater responsibility for climate change mitigation than developing countries should. The CBDR principle could therefore be said to be based on the polluter-pays principle where historical contribution to climate change and respective ability to combat climate change become measures of responsibility for environmental protection.

Concept of CBDR evolved from notion of "common concern" in Convention for the Establishment of an Inter-American Tropical Tuna Commission of 1949 and "common heritage of mankind" in United Nations Convention on the Law of the Sea, 1982.