This paper aims to show the work that one of the main supranational organizations has been doing on the environment, which since the 1970s, is urging States to harmonize economic and social policies. The OECD is concerned about climate change and therefore calls for the early adaptation of development policies to this phenomenon. With a view to meeting the challenges arising from the heavy dependence on natural resources and seeking to curb their degradation, the Organization has set economic and environmental projections to 2030, and has proposed important strategies for its realization until the middle of the millennium.