The United Nations Framework Convention on Climate Change (UNFCCC) is an international environmental treaty. It was adopted in New York on May 9, 1992, and opened for signature at the 1992 Earth Summit in Rio de Janeiro, entering into force on March 21, 1994. The Convention was created to address the threat of anthropogenic (human-caused) climate change. Its ultimate objective, stated in Article 2, is the "stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system".
The UNFCCC functions as a framework, establishing principles rather than legally binding emission targets for individual nations. A key mechanism is the principle of "common but differentiated responsibilities" (CBDR), which recognizes that developed countries, categorized as Annex I and Annex II parties, bear the primary responsibility for mitigation and providing financial resources to developing countries (Non-Annex I). The supreme decision-making body is the Conference of the Parties (COP), which meets annually.
The UNFCCC is the foundational treaty for subsequent, more specific climate agreements. It connects directly to the 1997 Kyoto Protocol and, more recently, the 2015 Paris Agreement. The Paris Agreement, which entered into force in 2016, is the current operational mechanism. It replaced the Kyoto Protocol's top-down targets with a bottom-up approach where all parties submit voluntary, self-determined climate pledges called Nationally Determined Contributions (NDCs). The UNFCCC remains the parent treaty, but the Paris Agreement has fundamentally changed the implementation structure by requiring commitments from all nations.