The principle recognizes historical difference in the contributions of developed and developing States to global environment problems, and differences in their respective economic and technical capacity to tackle these problems. Despite their common responsibilities, important differences exist between the stated responsibilities of developed and developing countries. The principle of common but differentiated responsibility includes two fundamental elements. The first concerns the common responsibility of States for the protection of the environment, or parts of it, at the national, regional and global levels. The second concerns the need to take into account the different circumstances, particularly each State’s contribution to the evolution of a particular problem and its ability to prevent, reduce and control the threat.
Common responsibility describes the shared obligations of two or more States towards the protection of a particular environmental resource. Common responsibility is likely to apply where the resource is shared, under the control of no state, or under the sovereign control of a state, but subject to a common legal interest. The concept of common responsibility evolved from an extensive series of international laws governing resources labeled as ‘common heritage of mankind’ or of ‘common concern.’ Differentiated responsibility of States for the protection of the environment is widely accepted in treaty and other State practices. It translates into differentiated environmental standards set on the basis of a range of factors, including special needs and circumstances, future economic development of countries, and historic contributions to the creation of an environmental problem.
In summary, States have common responsibilities to protect the environment and promote sustainable development, but due to different social, economic, and ecological situations, countries must shoulder different responsibilities. The principle therefore provides for asymmetrical rights and obligations regarding environmental standards, and aims to induce broad State acceptance of treaty obligations, while avoiding the type of problems typically associated with a lowest common denominator approach. The principle also reflects the core elements of equity, placing more responsibility on wealthier countries and those more responsible for causing specific global problems. Perhaps more importantly, the principle also presents a conceptual framework for compromise and co-operation in effectively meeting environmental challenges.