The United Nations Framework Convention on Climate Change (UNFCCC) is an international environmental treaty that serves as the foundational document for global climate action. It was adopted on May 9, 1992, and opened for signature at the United Nations Conference on Environment and Development (UNCED), or the Earth Summit, in Rio de Janeiro. The treaty entered into force on March 21, 1994, with the purpose of combating "dangerous human interference with the climate system" by stabilizing greenhouse gas concentrations in the atmosphere.
The Convention works by establishing general obligations and a structure for international cooperation, rather than setting concrete, legally binding emission targets for all countries. Its core mechanism is the principle of "common but differentiated responsibilities" (CBDR), which acknowledges that all countries must act, but developed nations should take the lead due to their greater historical emissions and capacity. The supreme decision-making body is the Conference of the Parties (COP), which meets annually to assess progress.
The UNFCCC is a framework that connects to subsequent, more specific legal instruments. The Kyoto Protocol, adopted in 1997, was the first to impose legally binding emission reduction targets, but only on developed countries. The most significant recent development is the Paris Agreement, adopted in 2015, which superseded the Kyoto Protocol's structure. The Paris Agreement brought all nations together under a binding agreement to limit global temperature rise to well below 2°C and pursue efforts for 1.5°C above pre-industrial levels, primarily through voluntary national climate action plans called Nationally Determined Contributions (NDCs).