By Kirsty McHugh, OUP UK
Next week sees the beginning of the United Nations Climate Change Conference, held in Copenhagen. The aim of the conference is to reach an ambitious global agreement including all the countries in the world. This week OUPblog will be posting a series of Countdown to Copenhagen blogs from some of our authors. Kicking things off is Professor Mark Maslin, who is the Head of Department and Director of the Environment Institute at University College London, and the author of Global Warming: A Very Short Introduction.
Climate change is the most important science issue of the 21st century, challenging the very structure of our global society. The COP 15 meeting at Copenhagen provides a real opportunity for global society to decide how to deal with this major threat. We already know that atmospheric carbon dioxide has risen from a pre-industrial level of 280 ppmv to 389 ppmv by 2009. This has already caused climate change; with clear evidence for a 0.75°C rise in global temperatures and 22 cm rise in sea level during the 20th century. In the last 150 years the twelve warmest years on record have all occurred in the last thirteen years: 1998 was the warmest, followed by 2005, 2002, 2003 and 2004, while 2008 was the 10th warmest year on record. The threat of climate change has been assessed in the Intergovernmental Panel on Climate Change (IPCC) 2007 synthesis report. Based on 23 complex climate models they predict that global temperatures by 2100 could rise by between 1.1°C and 6.4°C (best estimates being 1.8˚C to 4˚C). Sea level could rise by between 28 cm and 79 cm, more if the melting of Greenland and Antarctica accelerates. The potentially effects of climate change on human society are devastating, including drastic changes in global health, agriculture, the economy, water resources, coastal regions, storms and other extreme climate events, and biodiversity. The IPCC states that the scientific evidence for global warming is unequivocal and there is very high confidence that this is due human activity. This view is supported by a vast array of learned organisations, including the Royal Society and American Association for the Advancement of Science. This is why the negotiations at COP15 at Copenhagen are so important.
I believe a legally binding agreement to limited global warming to a maximum of 2˚C above pre-industrial temperatures is required at Copenhagen. This has profound implications as the science tell us this is equivalent to putting a total of a trillion tonnes of carbon in the atmosphere. As we have already emitted half a trillion tonnes the political challenge at Copenhagen and COP16 in Mexico is how to limit the world to just another half a trillion tonnes of carbon. The first challenge is the essential involvement of Developing countries in long-term carbon reduction targets because the scale their current and future pollution. Of course this will only occur is the rich countries such as the EU and USA lead the way with stringent cuts. It is also moral imperative, however, that people in the poorest countries have the right to develop and to obtain the same life style we currently enjoy. We also need massive investment in alternative/renewable power sources and low carbon technology. One of the key ways that Developing Countries may be encouraged to achieve reduction targets given a positive lead by the western world would be through carbon trading and other financial incentives. The second challenge at Copenhagen is to produce an agreement on how to reduce carbon emissions from deforestation. Currently land use changes emit about 20% of the all the carbon pollution. I believe at Copenhagen there could be a real binding agreement agreed to fund an international reduction program.
Though Copenhagen is politically challenging there is a strong economic argument for action; Lord Stern argues if we do everything we can now to mitigate emission and adapt to climate change it will cost us 2% of World GDP every year. However, if we do nothing then the impacts of climate change could cost between up to 20% of World GDP every year. I would argue that even if the cost-benefit of solving global warming is less than suggested by Lord Stern there is an undeniable ethical case of preventing the deaths of tens of millions of people and the increase in human misery for billions. My feeling is that the possibility of a fully comprehensive deal at Copenhagen is unlikely but it is an essential stepping-stone for one to be signed at COP16 in Mexico next year. This is because currently the USA do not have a Cap-and-Trade carbon system agreed. By next year, hopefully the Waxman-Markey Bill may have passed through both Houses and be ready to be enacted. I do, however, believe there may be surprises at Copenhagen such as a major deal on saving the rainforests.