The United Nations Framework Convention on Climate Change was adopted on 9 May 1992, in New York, and opened for signature at the UN Conference on Environment and Development in June 1992 at Rio, where it received 155 signatures. The Convention entered into force on 21 March 1994 (90 days after the 50th ratification).
Since the adoption of the Convention, the INC has met six times. The sixth session of the INC (INC-6) identified those tasks specified in the Convention to be carried out by the COP at its first session (COP-1) and decided that these tasks would form a large part of INC work in preparing for COP-1. During these INC sessions, scientific work was done on improving the methodologies for measuring emissions from various sources, but the larger scientific problem of choosing the best methodology to measure the removal of carbon dioxide by "sinks" remains. The other major task before negotiators was to work on the difficult issue of financial support for implementation, particularly for developing country Parties who will require new and additional resources to obtain data and implement necessary measures.