¹ Keith, D.W., ‘Geoengineering the Climate: History and Prospect’ (2000) 25(1) Annual Review of Energy and the Environment, pp. 245–84, at 245CrossRefGoogle Scholar; Shepherd, J.G. et al. ., Geoengineering the Climate: Science, Governance and Uncertainty (The Royal Society, 2009), at p. 1.Google Scholar

² See, e.g., Environmental Pollution Panel, Restoring the Quality of Our Environment (President’s Science Advisory Council, 1965); Schelling, T.C., ‘Climatic Change: Implications for Welfare and Policy’, in US National Research Council, Changing Climate (National Academies Press, 1983), pp. 449–82Google Scholar; US National Research Council, Policy Implications of Greenhouse Warming: Mitigation, Adaptation, and the Science Base (National Academies Press, 1992)Google Scholar; Keith, n. 1 above.

³ Parson, E.A. & Ernst, L.N., ‘International Governance of Climate Engineering’ (2013) 14(1) Theoretical Inquires in Law, pp. 307–38Google Scholar; E. Parson et al., ‘“Mechanics” of SRM Research Governance’, background paper for the Solar Radiation Management Governance Initiative, Mar. 2011, available at: http://www.srmgi.org/files/2011/09/SRMGI-Mechanics-background-paper.pdf.

⁴ See, e.g., Barrett, S., Environment and Statecraft (Oxford University Press, 2003)Google Scholar; Kemfert, C., ‘Climate Coalitions and International Trade’ (2004) 32(1) Energy Policy, pp. 455–65Google Scholar; Aldy, J. & Stavins, R., Architectures for Agreement (Cambridge University Press, 2007)Google Scholar; Hovi, J. et al. ., ‘Implementing Long-Term Climate Policy’ (2009) 9(3) Global Environmental Politics, pp. 20–39Google Scholar; Bernauer, T., ‘Climate Change Politics’ (2013) 16(1) Annual Review of Political Science, pp. 421–48.Google Scholar

⁵ See, e.g., Asilomar Scientific Organizing Committee, The Asilomar Conference Recommendations on Principles for Research into Climate Engineering Techniques (Climate Institute, 2010)Google Scholar; US National Research Council, Advancing the Science of Climate Change: America’s Climate Choices (National Academies Press, 2010), at pp. 377–88Google Scholar; Shepherd et al., n. 1 above, at p. 1; Bipartisan Policy Center, Geoengineering: A National Strategic Plan for Research on the Potential Effectiveness, Feasibility, and Consequences of Climate Remediation Technologies (Bipartisan Policy Center, 2011), at p. 3.

⁶ B.J. Soden et al., ‘Global Cooling after the Eruption of Mount Pinatubo: A Test of Climate Feedback by Water Vapor’ (2002) 296(5568) Science, pp. 727–30, at 727.

⁷ Parson, E.A. & Keith, D.W., ‘End the Deadlock on Governance of Geoengineering Research’ (2013) 339(6131) Science, pp. 1278–9.Google Scholar

⁸ Keith, D.W., Parson, E.A. & Morgan, M.G., ‘Research on Global Sun Block Needed Now’ (2009) 463(28) Nature, pp. 426–7, at 426.Google Scholar

⁹ McClellan, J. et al. ., Geoengineering Cost Analysis: Final Report (Aurora Flight Sciences Corporation, 2011)Google Scholar; Pierce, J.R. et al. ., ‘Efficient Formation of Stratospheric Aerosol for Climate Engineering by Emission of Condensable Vapor from Aircraft’ (2010) 37(18) Geophysical Research Letters, pp. 1–5.Google Scholar

¹⁰ McClellan et al., ibid.

¹¹ Barrett, S., ‘The Incredible Economics of Geoengineering’ (2008) 39(1) Environmental and Resource Economics, pp. 45–54, at 49Google Scholar; Keith et al., n. 8 above.

¹² Teller, E. et al. ., Active Climate Stabilization: Practical Physics-based Approaches to Prevention of Climate Change (Lawrence Livermore National Laboratory, 2002)Google Scholar; Levitt, S.D. & Dubner, S.J., SuperFreakonomics: Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance (Harper Collins, 2009), at pp. 235–300.Google Scholar

¹³ Bala, G. et al. ., ‘Impact of Geoengineering Schemes on the Global Hydrological Cycle’ (2008) 105(22) Proceedings of the National Academy of Sciences, pp. 7664–9, at 7664.Google Scholar

¹⁴ Robock, A. et al. ., ‘Regional Climate Responses to Geoengineering with Tropical and Arctic SO₂ Injections’ (2008) 113(D16) Journal of Geophysical Research: Atmospheres (1984–2012), D16101.CrossRefGoogle Scholar

¹⁵ Doney, S.C. et al. ., ‘Ocean Acidification: The Other CO₂ Problem’ (2009) 1 Marine Science, pp. 169–92.Google Scholar

¹⁶ MacCracken, M.C., ‘On the Possible Use of Geoengineering to Moderate Specific Climate Change Impacts’ (2009) 4(4) Environmental Research Letters, 045107.Google Scholar

¹⁷ See, e.g., informal consultations undertaken by the Solar Radiation Management Governance Initiative (SRMGI) (e.g., at http://www.srmgi.org/events/african-involvement-in-solar-geoengineering); discussions at geoengineering side events at Copenhagen climate meetings, Dec. 2009 (presentation slides and video of discussions at http://www.cigionline.org/articles/2009/12/cop-15-side-event-international-governance-geoengineering-research); UK public dialogue on geoengineering (summary report ‘Experiment Earth: Report on a Public Dialogue on Geoengineering’, Aug. 2010, available at: http://www.nerc.ac.uk/about/consult/geoengineering-dialogue-final-report.pdf.

¹⁸ Within the exclusive economic zones (EEZ) of other nations and the airspace over them, the legal status of CE activities would depend on the interpretation of certain provisions of the United Nations Convention on the Law of the Sea (UNCLOS), (Montego Bay (Jamaica), 10 Dec. 1982, in force 16 Nov. 1994, available at: http://www.un.org/depts/los), particularly the regime for ‘marine scientific research’: see A. Hubert, ‘The New Paradox in Marine Scientific Research: Regulating the Potential Environmental Impacts of Conducting Ocean Science’ (2011) 42(4) Ocean Development & International Law, pp. 329–55.

¹⁹ For detailed discussions of the limited applicability of existing treaty obligations to CE, see, e.g., Parson et al., n. 3 above; A. Ghosh & J. Blackstock, ‘SRMGI Background Paper: International’, background paper for the SRMGI, Mar. 2011, at p. 16, available at: http://www.srmgi.org/files/2011/09/SRMGI-International-background-paper.pdf; Shepherd et al., n. 1 above, at p. 40; see also Ralph Bodle et al., Regulatory Framework for Climate-related Geoengineering Relevant to the Convention on Biological Diversity (Convention on Biological Diversity, 2012), UNEP/CBD/SBSTTA/16/INF/29.

²⁰ Montreal Protocol on Substances that Deplete the Ozone Layer, Montreal (Canada), 16 Sep. 1987, in force 1 Jan. 1989, available at: http://ozone.unep.org.

²¹ Kyoto Protocol to the United Nations Framework Convention on Climate Change, Kyoto (Japan), 10 Dec. 1997, in force 16 Feb. 2005, available at: http://unfccc.int/kyoto_protocol/items/2830.php.

²² Protocol to Abate Acidification, Eutrophication and Ground-level Ozone, Gothenburg (Sweden), 30 Nov. 1999, in force 17 May 2005, available at: http://www.unece.org/env/lrtap.

²³ Geneva (Switzerland), 13 Nov. 1979, in force 16 Mar. 1983, available at: http://www.unece.org/env/lrtap.

²⁴ Although not explicitly restricted to these, the primary focus of the Treaty is emissions from large stationary sources, so the applicability of its emissions limits to national participation in a CE programme that spreads SO₂ in the atmosphere would require a substantial further negotiation by Parties. Moreover, even if Parties agreed that national distribution of SO₂ as part of a CE programme counted towards national emissions limits, Parties with the largest budgets could accommodate CE programmes within these, and there are specific reasons why these limits would not constrain CE conducted by Russia, the US or Canada, even if it did for other states. For these three nations alone, emissions limits apply only to part of their national territory: the European part of Russia, roughly the south-eastern quarter of Canada, and the lower 48 states of the US. Moreover, emissions limits for the US and Canada are characterized as ‘indicative values’ rather than binding limits. Finally, Russia and Canada are Parties to the underlying Convention, but not to this Protocol. See the 1999 Gothenburg Protocol, ibid., Art. III, and Annex II, including Tables 1 and 2.

²⁵ Convention on the Prohibition of Military or Any Hostile Use of Environmental Modification Techniques, Geneva (Switzerland), 18 May 1977, in force 5 Oct. 1978, available at: http://www.icrc.org/applic/ihl/ihl.nsf/INTRO/460.

²⁶ At the 30^th Meeting of Contracting Parties to the London Convention and 3^rd Meeting of Contracting Parties to the London Protocol, delegates adopted Resolution LC-LP.1(2008), which states that ‘ocean fertilization activities other than legitimate scientific research should not be allowed’, and that such other activities are ‘contrary to the aims of the Convention and Protocol and do not currently qualify for any exemption from the definition of dumping in Article III.1(b) of the Convention and Article 1.4.1 of the Protocol’: see International Maritime Organization, Resolution LC-LP.1(2008) on the Regulation of Ocean Fertilization, 30^th Meeting of Contracting Parties to the London Convention and 3^rd Meeting of Contracting Parties to the London Protocol, adopted 31 Oct. 2008, available at: http://www.imo.org/blast/mainframemenu.asp?topic_id=1969.

²⁷ Rio de Janeiro (Brazil), 5 June 1992, in force 29 Dec. 1993, available at: http://www.cbd.int/convention/text.

²⁸ COP 10 Decision X/33, Biodiversity and Climate Change, Nagoya (Japan), 2010, available at: http://www.cbd.int/decision/cop/?id=12299.

²⁹ The Decision invites Parties and other governments to ensure, inter alia, that ‘no climate-related geo-engineering activities that may affect biodiversity take place, until there is an adequate scientific basis on which to justify such activities and appropriate consideration of the associated risks for the environment and biodiversity and associated social, economic and cultural impacts, with the exception of small scale scientific research studies that would be conducted in a controlled setting in accordance with Article 3 of the Convention, and only if they are justified by the need to gather specific scientific data and are subject to a thorough prior assessment of the potential impacts on the environment’ (ibid., para. 8(w)).

³⁰ Williamson, P. & Turley, C., ‘Ocean Acidification in a Geoengineering Context’ (2012) 370(1974) Philosophical Transactions of the Royal Society, pp. 4317–42.Google Scholar

³¹ International Maritime Organization, ‘Statement of Concern Regarding Iron Fertilization of the Oceans to Sequester CO₂’, LC-LP.1/Circ.14, 13 July 2007, endorsed by the 29^th Consultative Meeting and the 2^nd Meeting of Contracting Parties, Nov. 2007, available at: https://www.whoi.edu/cms/files/London_Convention_statement_24743_29324.pdf.

³² Resolution LC-LP.1, n. 25 above; Resolution LC-LP.2(2010) on the Assessment Framework for Scientific Research Involving Ocean Fertilization, 32^nd Consultative Meeting of the Contracting Parties to the London Convention and 5^th Meeting of the Contracting Parties to the London Protocol, International Maritime Organization, adopted on 14 Oct. 2010, available at: http://www.imo.org/blast/mainframemenu.asp?topic_id=1969.

³³ The situation under the London Protocol is slightly more complicated. This protocol was negotiated under the London Convention, an earlier treaty that it is intended to eventually replace. The US is not a party to the London Protocol but is a party to the earlier Convention. Consequently, if a decision controlling ocean fertilization were to be adopted in some form that was binding under both the Protocol and the Convention, the US would be bound by it as a party to the Convention.

³⁴ Vienna (Austria), 22 Mar. 1985, in force 22 Sep. 1988, available at: http://ozone.unep.org/pdfs/viennaconvention2002.pdf. Art. 2 states: ‘Parties shall take appropriate measures … to protect human health and the environment against adverse effects resulting or likely to result from human activities which modify or are likely to modify the ozone layer’.

³⁵ N. 18 above. Part XII, e.g., Art. 192: ‘States have the obligation to protect and preserve the marine environment’; Art. 194:1: ‘States shall take … all measures consistent with this Convention that are necessary to prevent, reduce, and control pollution of the marine environment from any source, using for this purpose the best practicable means at their disposal and in accordance with their capabilities’.

³⁶ Rio Declaration on Environment and Development, 14 June 1992, Principle 2, available at: http://tiny.cc/Rio-Declaration-1992. See also International Court of Justice (ICJ), Legality of the Threat or Use of Nuclear Weapons, General Assembly Advisory Opinion, ICJ Reports (1996), at p. 22.

³⁷ ICJ, Case Concerning Pulp Mills on the River Uruguay (Argentina v. Uruguay), Judgment, 20 Apr. 2010, ICJ Reports (2010), at p. 14.

³⁸ G. Wagner & M.L. Weitzman, ‘Playing God’, Foreign Policy, 24 Oct. 2012, available at: http://www.foreignpolicy.com/articles/2012/10/22/playing_god?page=0,2&wp_login_redirect=0

³⁹ See, e.g., Victor, D.G., ‘On the Regulation of Geoengineering’ (2008) 24(2) Oxford Review of Economic Policy, pp. 322–6, at 324Google Scholar; David, W.D., ‘What Does “Green” Mean? Anthropogenic Climate Change, Geoengineering, and International Environmental Law’ (2009) 43 Georgia Law Review, pp. 901–50, at 926Google Scholar; Squillace, M., ‘Climate Change and Institutional Competence’ (2010) 41 University of Toledo Law Review, pp. 889–908, at 899Google Scholar; Shepherd et al., n. 1 above, at p. 50.

⁴⁰ I owe this provocative idea to discussions with David Keith.

⁴¹ Concern about the potential for conflict from control of weather and climate is as old as thermonuclear weapons. John von Neumann, leader of the pioneering computer project that performed early calculations of the behaviour of both thermonuclear weapons and weather forecasting, suggested that control of weather and climate held even greater potential for international conflict than nuclear weapons: see J. von Neumann, ‘Can We Survive Technology?’ (June 1955) Fortune, p. 151; see also the discussion in Dyson, G., Turing’s Cathedral (Pantheon Press, 2012), at pp. 158–74.Google Scholar

⁴² Morgan, M.G. & Ricke, K., Cooling the Earth through Solar Radiation Management: The Need for Research and Approach to its Governance (International Risk Governance Council, 2011)Google Scholar; Ricke, K. et al. ., ‘Regional Climate Response to Solar Radiation Management’ (2010) 3 Nature Geoscience, pp. 537–41.Google Scholar

⁴³ MacMartin, D.G. et al. ., ‘Management of Trade-offs in Geoengineering through Optimal Choice of Non-Uniform Radiative Forcing’ (2013) 3 Nature Climate Change, pp. 365–8.Google Scholar

⁴⁴ To take this speculation even further, risks of conflict might be most severe if CE exhibits intermediate degrees of regional controllability. With no regional controllability, only crude limitation of aggregate global climate risk would be possible. With moderate controllability, inter-regional trade-offs would be likely to emerge – e.g., one intervention might increase the risk of drought in Region A, while another shifts it to Region B. But, as controllability increases further, there might emerge some ability to simultaneously optimize in multiple regions, so if the control mechanism is trusted by all – a large assumption, to be sure – inter-regional trade-offs and associated conflicts might decrease.

⁴⁵ L. Lane, ‘Geoengineering: Assessing the Implications of Large-Scale Climate Intervention’, statement presented at Hearing No. 111-62, US House of Representatives Committee on Science and Technology, Washington, DC (US), 5 Nov. 2009, at pp. 39–41, available at: http://www.gpo.gov/fdsys/pkg/CHRG-111hhrg53007/pdf/CHRG-111hhrg53007.pdf; see also Parson & Keith, n. 7 above.

⁴⁶ Parson & Keith, n. 7 above.

⁴⁷ See, e.g., J. Emmerling & M. Tavoni, ‘Geoengineering and Abatement: A “Flat” Relationship under Uncertainty’, Fondazione Eni Enrico Mattei Working Paper No. 31.2013, 16 Apr. 2013, available at: http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2251733; J.B. Moreno-Cruz and D.W. Keith, ‘Climate Policy under Uncertainty: A Case for Solar Geoengineering’ (2012) Climatic Change, available at: http://link.springer.com/article/10.1007/s10584-012-0487-4/fulltext.html.

⁴⁸ Discussions of the moral hazard problem can be found in all the major reviews and assessments of CE, e.g., Shepherd et al., n. 1 above; Bipartisan Policy Center, n. 5 above; Asilomar Scientific Organizing Committee, n. 5 above. For more extended discussions see, e.g., Gardiner, Stephen M., A Perfect Moral Storm: The Ethical Tragedy of Climate Change (Oxford University Press, 2011)Google Scholar; Hale, B., ‘The World that Would Have Been: Moral Hazard Arguments against Geoengineering’, in Preston, C.J. (ed), Engineering the Climate: The Ethics of Solar Radiation Management (Lexington Books, 2012)Google Scholar; A. Lin, ‘Does Geoengineering Present a Moral Hazard?’ (2013) 40 Ecology Law Quarterly (forthcoming), available at: http://ssrn.com/abstract=2152131, 23 Aug. 2012.

⁴⁹ Suggestions for such alternative forums for action have been widely made. See, e.g., Victor, D.G., The Collapse of the Kyoto Protocol and the Struggle to Slow Global Warming (Princeton University Press, 2004)Google Scholar; Dessler, A. & Parson, E.A., The Science and Politics of Climate Change (Cambridge University Press, 2009)Google Scholar; The Leaders-20 (L20) Project, ‘Meeting Report: Key Elements in Breaking the Climate Change Deadlock’, Paris (France), 31 Mar.-1 Apr. 2008, available at: http://www.l20.org/publications/38_qF_Paris-Meeting-Report-Final.pdf; R.B. Stewart, M. Oppenheimer & B. Rudyk, ‘Building a More Effective Global Climate Regime through a Bottom-Up Approach’ (2013) 14(1) Theoretical Inquiries in Law, pp. 273–306.

⁵⁰ The Group of Eight + Five (G8+5) nations include the US, Russia, Japan, Germany, United Kingdom (UK), France, Italy, and Canada, plus China, India, Brazil, Mexico, and South Africa. To these 13, the Major Economies Forum adds Australia, South Korea, and Indonesia, plus the European Union (EU). To these 17, the G-20 adds Turkey, Saudi Arabia, and Argentina. See Parson et al., n. 3 above.

⁵¹ See, e.g., Parson & Ernst, n. 3 above.

⁵² For the seminal discussion of the credibility of threats see Schelling, T.C., The Strategy of Conflict (Harvard University Press, 1960).Google Scholar

⁵³ Sagoff, M., ‘The Poverty of Economic Reasoning about Climate Change’ (2010) 30 Philosophy and Public Policy Quarterly, pp. 8–15.Google Scholar

⁵⁴ Parson & Keith, n. 7 above

⁵⁵ Parson & Ernst, n. 3 above.