The world could have a '50-50 chance' of avoiding global warming of more than 2˚C, regarded by many scientists as the threshold for dangerous climate change, if a strong political agreement can be reached at the United Nations conference in Copenhagen this month, and then implemented, according to two reports launched this week (1 December 2009) by Nicholas Stern at the London School of Economics and Political Science.
Speaking ahead of a major speech about the prospects for the Copenhagen meeting, Lord Stern, chair of the Grantham Research Institute on Climate Change and the Environment, said: 'It is possible to create a 50-50 chance of avoiding a rise in global average temperature of more than 2˚C, which many scientists regard as the threshold for 'dangerous' climate change. To do this we need to halt and reverse the growth of annual emissions of carbon dioxide and other greenhouse gases, reducing them from about 47 billion tonnes in 2010 to about 44 billion tonnes in 2020, and decreasing to much less than 20 billion tonnes in 2050. If you add up the most ambitious of the intentions to reduce emissions that have been expressed so far, they are, if delivered, around 2 billion tonnes higher than the overall 2020 goal.'
He added: 'Although we are making some progress on commitments for cuts in greenhouse gas emissions, a major challenge is for rich countries to provide sufficient financial support to help developing countries to reduce their emissions and to adapt to those impacts that cannot now be avoided. The rich countries should find US$50 billion, or about 0.1 per cent of their gross domestic product, a year by 2015 to help the developing countries, over and above existing commitments on development aid.'
Lord Stern said: 'The European Union can continue to show leadership on climate change, and position itself at the forefront of the dynamic and exciting transition to a low-carbon economy, by highlighting its readiness to commit to its stronger target of reducing emissions by 30 per cent by 2020 compared with 1990. It should also push for an agreement by the rich countries to provide US$50 billion to the developing countries by 2015, and make its own strong contribution. The UK has been a leader through its climate change legislation and strategic action plan, and in arguing for strong financial support for the developing world. It should continue this leadership and contribute at least $3 billion per year by 2015, based on its relative wealth. The Government has a key opportunity to make clear commitments in the Pre-Budget Report next week.'
Lord Stern concluded: 'An agreement now lies in the hands of world leaders who can make decisions across the full range of political issues that relate to climate change. They must demonstrate determination and vision. We must have an agreement that will ensure future generations can enjoy the opportunities for sustainable growth that are offered by the low-carbon economy, and that are free from the severe risks that would arise from unchecked climate change. We cannot afford the cost of failure on climate change.'
Dr Nicola Ranger, a research fellow at the Centre for Climate Change Economics and Policy and co-author of the assessment of global annual emissions paths, said: 'We have carried out a scientific and economic assessment of the range of paths for global annual emissions that are consistent with a 50 per cent chance of avoiding a rise of more than 2˚C. All of these pass through a window of between 40 and 48 billion tonnes in 2020 and then decrease to between 14 and 17 billion tonnes in 2050. In view of the risks from delayed action and the economic benefits of acting early, it would be smart to aim towards the bottom of this window in 2020.'
Dr Alex Bowen, a principal research fellow at the Grantham Research Institute on Climate Change and the Environment and co-author of the assessment of global annual emissions paths, said: 'It appears entirely feasible to lower global annual emissions to 44 billion tonnes or below by 2020 if effective policies are introduced now and countries take advantage of 'low-hanging fruit' such as energy efficiency measures. However weak or delayed action to reduce emissions in the near term would require much stronger cuts after 2020, which would be likely to increase significantly the economic costs of meeting a 2˚C target, and might make it impossible.'
A podcast of the public lecture by Nicholas Stern on Deciding our Future in Copenhagen: will the world rise to the challenge of climate change? is now online here.
Nicholas Stern was second permanent secretary at HM Treasury between 2003 and 2007. He also served as head of the Government Economic Service, head of the review of economics of climate change (the results of which were published in The Economics of Climate Change: the Stern review' in October 2006), and director of policy and research for the Commission for Africa. His previous posts included senior vice-president and chief economist at the World Bank, and chief economist and special counsellor to the president at the European Bank for Reconstruction and Development. He was recommended as a non-party-political life peer by the UK House of Lords Appointments Commission in October 2007. Baron Stern of Brentford was introduced in December 2007 to the House of Lords, where he sits on the independent cross-benches.
The Grantham Research Institute on Climate Change and the Environment (http://www.lse.ac.uk/grantham) was launched at the London School of Economics and Political Science in October 2008. It is funded by The Grantham Foundation for the Protection of the Environment (http://www.granthamfoundation.org/).
Lord Stern is also chair of the Centre for Climate Change Economics and Policy (http://www.cccep.ac.uk/), which is hosted by the University of Leeds and the London School of Economics and Political Science. It is funded by the UK Economic and Social Research Council (http://www.esrc.ac.uk/) and Munich Re (http://www.munichre.com/). He is also I.G. Patel Professor of Economics and Government and director of the India Observatory at London School of Economics and Political Science.
2 December 2009