EnvironmentSmith School of Enterprise and the Environment21in tackling climate change. At Cancun, the issue was essentially put aside in the final agreements and decisions on it postponed for a further year. This did allow advances to be made in other areas that were introduced in the Copenhagen Accord. It remains unlikely that anything other than a severely weakened legally binding agreement would be signed by the major emitters of CO2. The future of the Kyoto Protocol does not look bright [6].In order to make rapid and realistic progress, focus needs to shift from form to function. Concentrating on creating a legally binding document will not produce the desired action. Instead, negotiations should focus on areas where progress has been made. For example, real progress was made in the areas of deforestation, technology, finance and adaptation. Concentrating and solidifying agreement on these areas will be considerably more productive. In addition, the pledge and review process provides a critically important new pathway for immediate action.Pledge-and-ReviewThe pledge-and-review process adopted by the Copenhagen Accord marked a move towards national-based action in mitigating and adapting to climate change. This approach was cemented via the integration of the voluntary commitments into the UNFCCC process at Cancun. This shift away from the top-down action has stimulated discussion about the relative merits of top-down versus bottom-up approaches [28]. In reality, both bottom-up and top-down policies are compatible and necessary. In developed and emerging countries the bottom-up approach is the only feasible way of ensuring participation. The pledge-and-review process marks a useful way to stimulate national action, and enables China and the US to participate. While the 'review' part of the pledge-and-review system was largely absent, and in fact was steered away from by the BASIC countries at Copenhagen, a large degree of transparency is embedded in the system. At Cancun progress was made in the area of monitoring and verification. Credit for this goes largely to the Indian Environment Minister. The publication of the pledges raises the level of ambition in the commitments as well as increasing pressure on all nations to meet them [29]. It is hoped that national commitments will therefore be met. A registry for developing countries to set out NAMAs for support by developed countries has also been set out. This is a useful tool as, at present, developed countries have a tendency to hold back finance due to scepticism over the end use of such money [30]. In this forum, developing countries can set out specific plans for action so that investors know where the money will be going, and this could stimulate increased funding. It also challenges developed countries using this as a line of defence over lack of financial support. Temperature and Emissions TargetsAn important step was made with the agreement on the target to limit anthropogenic warming to 2 ?C. This is a good 'goal'. One of us has pointed out on many occasions, since 2005, that there is a high degree of uncertainty in translating a specific limitation on an asymptotic figure for temperature rise to a stabilisation target figure for GHG emissions. For example, if the asymptote for GHG atmospheric levels is 450 ppm CO2 equivalent, the best available science produces a rather broad probability distribution function [31] peaking at 2.1 ?C but with a so-called 'fat tail' to high temperatures. Even at this low level of GHGs, there is a 20 per cent probability - based on current science - that the ultimate temperature increase would be more than 3 ?C. The scientific message is clear: the risk of a dangerously high temperature at any level above the present (387 ppm CO2; approximately 420 ppm CO2 equivalent) is relatively high. GHG emissions must be reduced, in order to manage this risk downward at the fastest rate that can be achieved. Paths to maintain a GHG asymptote below 450 ppm CO2 equivalent were developed some years ago by the UK Government and one path to 550 CO2 equivalent was published in the UK Government's Stern Report [32]. 4Chapter 4Chapter 4: Learning from the Negotiation Process

22Smith School of Enterprise and the EnvironmentSmith Figure 4 shows the business as usual emissions trajectories prior to 2007(curve a, 2007) and after the global debt crisis (curve b, 2009). Trajectories are also shown for stabilisation at 550 ppm CO2 equivalent (curve c) and 450 ppm CO2 equivalent (curves d, e and f). Curves d, e and f all represent pathways which achieve the same objective; stabilisation at 450 ppm. These curves demonstrate that it is the total emissions over the time period shown that determines the asymptote, not the rate of emissions. It is the build up of CO2 and other GHG's in the atmosphere which causes the temperature to rise. As recently pointed out [33], it is therefore possible to estimate the total amount of fossil fuel (expressed as C) burnt to CO2 that would generate an estimated mean temperature rise of 2 ?C. This is 1 trillion tonnes of carbon, with a standard uncertainty of 1.6 to 2.6 ?C. Over half of this amount has already been emitted. (Note that this estimate excludes other GHGs).The curves in figure 4 can be simply restated. In 2010, global anthropogenic activity is resulting in the emission of 36 bn tonnes of CO2 equivalent, as shown on the upper business-as-usual curve. Curve d demonstrates that global emissions should be reduced to 18 bn tonnes by 2050, i.e. a 50 per cent decrease. Taking 18 billion tonnes per annum as averaged across the expected population of 9 billion by mid-century yields 2 tonnes per person. Based on this figure, the UK Government revised its commitment of a 60 per cent reduction by 2050 made in 2003 to a reduction of 80 per cent, made in 2007. Currently UK emissions are at 10 tonnes per person per annum, so the British commitment equates to a reduction to 2 tonnes by 2050. This unilateral commitment, followed now by the EU, represents an interesting political and ethical statement. It suggests that the emissions target per country by mid-century could be determined Chapter 4Chapter Figure 4- Predicted future greenhouse emissions according to several different scenarios; trajectory a represents the 2007 business-as-usual predicted emissions; b shows the 2009 business-as-usual predicted emissions following the global economic collapse; c shows an emissions trajectory enabling stabilisation at 550 ppm CO2 equivalent; d, e and f show three different pathways to stabilisation at 450 ppm CO2 equivalent. Note: Emissions expressed in gigatonnes of carbon, to convert to gigatonnes of carbon dioxide multiply by 3.67. Adapted from UK Department of Environment, Food and Rural Affairs.