Climate change as an issue first came to real prominence in the 1980s and, faced with the mounting evidence of global warming, some 154 heads of state met at the "Earth Summit" in Rio de Janeiro in 1992. This summit resulted in the signing of the UN Framework Convention on Climate Change (UNFCCC) which aimed, on a voluntary basis, to "achieve stabilization of greenhouse gas concentrations in the atmosphere at a low enough level to prevent dangerous anthropogenic interference with the climate system".
Despite this treaty, emissions continued to rise and in 1997 this led to the signing of the legally binding Kyoto Protocol at the third Conference of UNFCC Parties (COP-3). This entered into force in 2005 following ratification by Russia and stipulates that:
Altogether the Kyoto Protocol had, as of December 2007, been ratified by some 176 countries (all its signatories apart from the USA and Kazakhstan) and, despite it's limitations, this remains today the most important international agreement for tackling climate change.
Looking to the future, a “roadmap” for developing a framework for greenhouse gas emissions reduction after 2012 was agreed at the Bali conference in 2007 (COP-13). This requires that negotiations on a successor to the Kyoto Protocol should commence at the Poznan conference in late 2008 (COP-14) and be concluded at a major summit in Copenhagen in 2009 (COP-15) at which a new protocol is hoped to be signed.