The First World Climate Conference recognized climate change as a serious problem in 1979. This scientific gathering explored how climate change might affect human activities. It issued a declaration calling on the world’s governments "to foresee and prevent potential man-made changes in climate that might be adverse to the well-being of humanity". It also endorsed plans to establish a World Climate Programme (WCP) under the joint responsibility of the World Meteorological Organization (WMO), the United Nations Environment Programme (UNEP), and the International Council of Scientific Unions (ICSU).

A number of intergovernmental conferences focusing on climate change were held in the late 1980s and early 1990s. Together with increasing scientific evidence, these conferences helped to raise international concern about the issue. Participants included government policy-makers, scientists, and environmentalists. The meetings addressed both scientific and policy issues and called for global action. The key events were the Villach Conference (October 1985), the Toronto Conference (June 1988), the Ottawa Conference (February 1989), the Tata Conference (February 1989), the Hague Conference and Declaration (March 1989), the Noordwijk Ministerial Conference (November 1989), the Cairo Compact (December 1989), the Bergen Conference (May 1990), and the Second World Climate Conference (November 1990).

The Intergovernmental Panel on Climate Change (IPCC) released its First Assessment Report in 1990. Established in 1988 by UNEP and WMO, the Panel was given a mandate to assess the state of existing knowledge about the climate system and climate change; the environmental, economic, and social impacts of climate change; and the possible response strategies. Approved after a painstaking peer review process, the Report confirmed the scientific evidence for climate change. This had a powerful effect on both policy-makers and the general public and provided the basis for negotiations on the Climate Change Convention.

In December 1990, the UN General Assembly approved the start of treaty negotiations. The Intergovernmental Negotiating Committee for a Framework Convention on Climate Change (INC/FCCC) met for five sessions between February 1991 and May 1992. Facing a strict deadline – the June 1992 Rio "Earth Summit" – negotiators from 150 countries finalized the Convention in just 15 months. It was adopted in New York on 9 May 1992.

The 1992 UN Framework Convention on Climate Change was signed by 154 states (plus the EC) at Rio de Janeiro. Twenty years after the 1972 Stockholm Declaration first laid the foundations of contemporary environmental policy, the Earth Summit became the largest-ever gathering of Heads of State. Other agreements adopted at Rio were the Rio Declaration, Agenda 21, the Convention on Biological Diversity, and Forest Principles.

The Convention entered into force on 21 March 1994. This was 90 days after the receipt of the 50^th instrument of ratification (after signing a convention a government must then ratify). The next critical date was 21 September when developed country Parties started submitting national communications describing their climate change strategies. Meanwhile, the INC continued its preparatory work, meeting for another six sessions to discuss matters relating to commitments, arrangements for the financial mechanism, technical and financial support to developing countries, and procedural and institutional matters. The INC was dissolved after its 11^th and final session in February 1995, and the Conference of the Parties (COP) became the Convention’s ultimate authority.

The Conference of the Parties held its first session in Berlin from 28 March - 7 April 1995. Delegates from 117 Parties and 53 Observer States participated in COP-1, as did over 2,000 observers and journalists. They agreed that the commitments contained in the Convention for developed countries were inadequate and launched the "Berlin Mandate" talks on additional commitments. They also reviewed the first round of national communications and finalized much of the institutional and financial machinery needed to support action under the Convention in the years to come. COP-2 was held at the Palais des Nations in Geneva from 8 - 19 June 1996.

The IPCC finalized its Second Assessment Report in December 1995. Published in time for COP-2, the Second Assessment Report was written and reviewed by some 2,000 scientists and experts world-wide. It was soon widely known for concluding that "the balance of evidence suggests that there is a discernible human influence on global climate." However, the Report did much more, for example confirming the availability of so-called no-regrets options and other cost-effective strategies for combating climate change.

The Kyoto Protocol was adopted at COP-3 in December 1997. Some 10,000 delegates, observers, and journalists participated in this high-profile event from 1 - 11 December. Because there was not enough time to finalize all the operational details of how the Protocol would work in practice, COP-4, held in Buenos Aires from 2-13 November 1998, agreed a two-year Plan of Action for completing the Kyoto rulebook. The agenda of COP-5, which took place in Bonn from 15 October – 5 November 1999, was based on this Plan.

A political agreement on the operational rulebook for the Protocol was reached at COP-6. Meeting from 6 to 25 November 2000, COP-6 made good progress but could not resolve all the issues in the time available. The meeting was suspended and then resumed from 16 to 27 July 2001 in Bonn. The resumed session reached agreement on the political principles of operational rulebook for the Kyoto Protocol. This agreement addressed the emissions trading system, the Clean Development Mechanism, the rules for counting emissions reductions from carbon "sinks", and the compliance regime. It also outlined a package of financial and technological support to help developing countries contribute to global action on climate change. The work of translating the Bonn Agreements into detailed legal texts was finalized at COP-7, which was held in Marrakech, Morocco, from 29 October to 9 November 2001. The Protocol is now ready for implementation.

The IPCC finalized its Third Assessment Report in early 2001. The Report concluded that the evidence for humanity’s influence on the global climate is now stronger than ever before, and it presented the most detailed picture to date of how global warming will affect various regions. It also confirmed that many cost-effective solutions to rising greenhouse gas emissions are available today; in many cases, however, governments will need to address various institutional, behavioral and other barriers before these solutions can realize their potential.