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Comment on ‘Impact of Current Climate Proposals’ by Bjorn Lomborg Robert E.T. Ward December 2015 Centre for Climate Change Economics and Policy Working Paper No. 244 Grantham Research Institute on Climate Change and the Environment Working Paper No. 218 The Centre for Climate Change Economics and Policy (CCCEP) was established by the University of Leeds and the London School of Economics and Political Science in 2008 to advance public and private action on climate change through innovative, rigorous research. The Centre is funded by the UK Economic and Social Research Council. Its second phase started in 2013 and there are five integrated research themes: 1. Understanding green growth and climate-compatible development 2. Advancing climate finance and investment 3. Evaluating the performance of climate policies 4. Managing climate risks and uncertainties and strengthening climate services 5. Enabling rapid transitions in mitigation and adaptation More information about the Centre for Climate Change Economics and Policy can be found at: http://www.cccep.ac.uk. The Grantham Research Institute on Climate Change and the Environment was established by the London School of Economics and Political Science in 2008 to bring together international expertise on economics, finance, geography, the environment, international development and political economy to create a worldleading centre for policy-relevant research and training. The Institute is funded by the Grantham Foundation for the Protection of the Environment and the Global Green Growth Institute. It has nine research programmes: 1. Adaptation and development 2. Carbon trading and finance 3. Ecosystems, resources and the natural environment 4. Energy, technology and trade 5. Future generations and social justice 6. Growth and the economy 7. International environmental negotiations 8. Modelling and decision making 9. Private sector adaptation, risk and insurance More information about the Grantham Research Institute on Climate Change and the Environment can be found at: http://www.lse.ac.uk/grantham. This working paper is intended to stimulate discussion within the research community and among users of research, and its content may have been submitted for publication in academic journals. It has been reviewed by at least one internal referee before publication. The views expressed in this paper represent those of the author(s) and do not necessarily represent those of the host institutions or funders. Comment on ‘Impact of Current Climate Proposals’ by Bjorn Lomborg Forthcoming in Global Policy, Vol. 7, Issue 1, February 2016 Robert E.T. Ward Grantham Research Institute on Climate Change and the Environment and ESRC Centre for Climate Change Economics and Policy London School of Economics and Political Science Houghton Street London WC2A 2AE UK Lomborg (2015) suffers from a fundamental methodological flaw which means that it could not fulfil its aim, stated in the ‘Abstract’, to investigate “the temperature reduction impact of major climate policy proposals implemented by 2030”. Projections of global mean surface temperature for the period up to 2100 are based on cumulative annual global emissions of greenhouse gases up to the end of the century. While Lomborg (2015) purports to analyse the temperature changes associated with policies affecting emissions up to 2030, the author fails to acknowledge that the temperature projections to 2100 are determined primarily by assumptions that are made about cumulative annual global emissions over the 70-year period after 2030, rather than cumulative annual emissions during the period up to 2030. The results cited by Lomborg (2015) are almost entirely due to the assumptions he makes about the post-2030 annual emissions from the United States, European Union and China. In each of these cases, annual emissions are assumed not to reduce any further, and in most cases, to rise. In some cases, emissions are assumed to rise by the end of the century to levels that reverse completely the effects of emissions reductions by 2030, and in some cases they also reverse the effects of emissions reductions that have occurred in the period up to 2015. As such, most of the “scenarios” used by Lomborg (2015) assume that climate policies are abandoned or reversed after 2030, and it is this assumption that primarily determines the projected global mean surface temperature in 2100. Hence, Lomborg (2015) does not investigate “the temperature reduction impact of major climate policy proposals implemented by 2030”. In the case of the United States, Figure 3 illustrates the assumptions made about annual emissions in relation to the pledge contained in the ‘intended nationally determined contribution’ (INDC) that was submitted to the secretariat of the United Nations Framework Convention on Climate Change (UNFCCC) on 31 March 20151. The INDC indicates that “the United States intends to achieve an economy-wide target of reducing its greenhouse gas emissions by 26-28 per cent below its 2005 level in 2025 and to make best efforts to reduce its emissions by 28%”. Figure 3 shows this reduction in emissions. However, the INDC also notes: “This target is consistent with a straight line emission reduction pathway from 2020 to deep, economy-wide emission reductions of 80% or more by 2050”. Lomborg (2015) disregards this statement, without explanation. Instead, he assumes for his “Optimistic USINDC” scenario that annual emissions by the United States remain at about the same level of around 4.6 gigatonnes of carbon-dioxide-equivalent (Gt CO2e) for the period between 2025 and 2100. For his ‘Pessimistic USINDC”, Lomborg (2015) assumes that annual emissions by the United States rise asymptotically to just under 6 Gt CO2e, exceeding current annual emissions levels during the 2070s. Hence this scenario completely reverses emissions reductions to be achieved by 2030 as well as emissions reductions achieved over about the past five years. Neither of these scenarios corresponds to expected policies beyond 2030. In the case of the 28 Member States of the European Union, Figure 7 shows the assumptions made about annual emissions in relation to the pledge contained in the INDC that was submitted to the secretariat of the UNFCCC on 6 March 20152. The INDC indicates that “the EU and its Member States are committed to a binding target of an at least 40% domestic reduction in greenhouse gas emissions by 2030 compared to 1990”. Figure 7 shows this reduction. However, the INDC also states that the 2030 target is “in line with the EU objective, in the context of necessary reductions according to the IPCC by developed countries as a group, to reduce its emissions by 80-95% by 2050 compared to 1990”. Lomborg (2015) ignores this statement, without explanation. Instead, he assumes for his “Optimistic EUINDC” scenario that annual emissions by the European Union rise gradually after 2030, exceeding current levels during the 2070s and reaching about 4.6 Gt CO2e by 2100. Hence this scenario assumes the reversal of emissions cuts achieved by 2030 as well as the reversal of reductions since about 2010. For his ‘Pessimistic EUINDC”, Lomborg (2015) assumes that annual emissions by the European Union climb even more steeply, exceeding current levels in about 2040 and eventually rising to about 6.7 Gt CO2e by 2100. Hence this scenario reverses all emissions cuts achieved since 1990 until the present day and those intended by 2030, with emissions due to be almost 50 per cent higher by the end of the century compared with today, and about 100 per cent higher than the target for 2030. Neither of these scenarios corresponds to expected policies beyond 2030. In the case of China, Figure 9 shows the assumptions made about annual emissions in relation to the pledge contained in the INDC that was submitted to the secretariat of the UNFCCC on 30 June 20153. The INDC indicates that China pledges “to lower carbon dioxide emissions per unit of GDP by 60% to 65% from the 2005 level”. Figure 9 shows a projection for annual emissions resulting from a 60 per cent cut in emissions intensity by 2030. However, the INDC also pledges that China will “achieve the peaking of carbon dioxide emissions around 2030 and making bets efforts to peak early”. Lomborg (2015) ignores this statement, without explanation. Instead, he assumes for his “Optimistic China INDC” scenario that annual emissions by China continue to rise gradually after 2030 until about 2060, exceeding 20 Gt CO2e from about 2050 up to 2100, compared with 11 Gt CO2e today and about 16 Gt CO2e in 2030. Hence this scenario assumes that emissions will increase by about a third after 2030, instead of reaching their peak in 2030. For his ‘Pessimistic China INDC”, Lomborg (2015) assumes that annual emissions by China climb even more steeply, 20 Gt CO2e during the 2040s and reaching about 22 Gt CO2e from 2060 up to 2100. Hence this scenario assumes that emissions increase by more than 45 per cent after 2030 instead of peaking. Neither of these scenarios corresponds to expected policies beyond 2030. Overall, Lomborg’s “optimistic” scenarios for the United States, European Union and China assume that their collective annual emissions rise from about 23 Gt CO2e in 2030 to more than 29 Gt CO2e in 2100. His “pessimistic” scenarios mean collective emissions would rise to more than 34.5 Gt CO2e. It is clear that the post-2030 assumptions largely obliterate the benefits of the emissions cuts up to 2030. It is for this reason that Lomborg (2015) projects that his “optimistic World INDCS” scenario means a rise in global mean surface temperature of 4.5°C by 2100, with the “pessimistic World INDCs” leading to an even bigger rise. The overwhelming majority of this warming is due to the assumptions by Lomborg (2015) about post2030 emissions. These temperature rises far exceed the warming projected by other studies that have analysed the INDCs. For instance, the International Energy Agency (2015) and Gütschow et al. (2015) have both projected that they would lead to a warming of 2.7°C by 2100. Indeed, both INDC scenarios described by Lomborg (2015) far exceed the temperature rises projected in ‘business as usual’ scenarios that omit the impact of the INDCs (eg Gütschow et al., 2015). This shows just how extreme the assumptions about post-2030 emissions made by Lomborg (2015) really are – they suggest that the INDCs would lead to an increase in warming compared with scenarios without the INDCs. Lomborg (2015) hides this fact by choosing to compare his scenarios against the most extreme scenario (RCP8.5) described by the Intergovernmental Panel on Climate Change (2013), which assumes strong growth in annual emissions throughout this century, leading to carbon dioxide concentrations in the atmosphere of more than 900 parts per million by 2100 (compared with the pre-industrial concentration of 280 parts per million and about 400 parts per million today) and a mean rise in global surface temperature of 4.3°C. Hence, a comparison of temperature projections based on the scenarios of Lomborg (2015), which depend largely on his extreme assumptions about post-2030 emissions, with RCP8.5 cannot be reasonably presented as an investigation into “the temperature reduction impact of major climate policy proposals implemented by 2030”. Notes 1. Available at: http://www4.unfccc.int/submissions/INDC/Published%20Documents/United%20St ates%20of%20America/1/U.S.%20Cover%20Note%20INDC%20and%20Accomp anying%20Information.pdf 2. Available at: http://www4.unfccc.int/submissions/INDC/Published%20Documents/Latvia/1/LV03-06-EU%20INDC.pdf 3. Available at: http://www4.unfccc.int/submissions/INDC/Published%20Documents/China/1/Chin a's%20INDC%20-%20on%2030%20June%202015.pdf References Gütschow, J., Jeffery, L., Alexander, R., Hare, B., Schaeffer, M., Rocha, M., Höhne, N., Fekete, H., van Breevoort, P. and Blok, K. (2015) ‘INDCs lower projected warming to 2.7°C: significant progress but still above 2°C’, Climate Action Tracker Update. Available from: http://climateactiontracker.org/assets/publications/CAT_global_temperature_updat e_October_2015.pdf Intergovernmental Panel on Climate Change (2013) Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp. International Energy Agency (2015) ‘Energy and Climate Change’, World Energy Outlook Special Briefing for COP21. Available from: http://www.iea.org/media/news/WEO_INDC_Paper_Final_WEB.PDF Lomborg. B. (2015) ‘Impact of Current Climate Proposals’, Global Policy, doi: 10.1111/1758-5899.12295