Scientific and political processes
Assessing the science of climate change is the responsibility of the Intergovernmental Panel on Climate Change (IPCC), established by the United Nations in 1988. It produces periodic reports on the state of play in climate science, gathering input from many hundreds of experts and developing a consensus on the current state of the climate, factors affecting it and possible future scenarios.
The latest IPCC report, its fourth, was published in spring 2007.
World leaders gathered at Rio de Janeiro in 1992 at the first Climate Change Convention (or Earth Summit), agreeing to stabilise global greenhouse gas emissions.
The Earth Summit has been followed by meetings aimed at turning this general aim into specific legally binding agreements (or protocols). Perhaps most significant was the 1997 meeting in Kyoto, where most industrialised countries agreed to legally binding reductions in emissions. The USA explicitly rejected the Kyoto Protocol in 2001. Russia signed up in 2004.
At Montreal in 2005, the Montreal Action Plan was agreed to extend the Protocol beyond its original expiry date of 2012. A formula for post-2012 was agreed at Bali in 2007. In December 2007, Australia, the last remaining major dissenter nation besides the USA, agreed to sign up to Kyoto.
Economic perspectives
Of many analyses of the economic impact of climate change, the most influential is the Stern Review, undertaken by former Chief Economist and Senior Vice-President of the World Bank Nicholas Stern (Lord Stern of Brentford) in 2006. His report argued that an investment of 1 per cent of GDP was necessary to prevent a recession of up to 20 per cent of GDP - much worse than others had predicted.
The Stern Review was criticised both for being too bleak and for being too optimistic. In 2008, Stern upgraded his estimate of the investment needed to 2 per cent of GDP, as warming was happening faster than predicted.
“We underestimated the risks...we underestimated the damage associated with temperature increases...and we underestimated the probabilities of temperature increases.” Lord Stern.