Geoengineering and Public Trust Doctrine Andrew Lockley, Gideon Futerman and D’Maris Coffman*

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Geoengineering and Public Trust Doctrine Andrew Lockley, Gideon Futerman and D’Maris Coffman* CCLR 2|2020 85 Geoengineering and Public Trust Doctrine Andrew Lockley, Gideon Futerman and D’Maris Coffman* Geoengineering (the deliberate modification of the climate system), has been discussed as a technique to control Anthropogenic Global Warming (AGW).1 Public Trust Doctrine (PTD) is used to hold assets that are not in private ownership in a form of collective ownership for public benefit; it is familiarly applied to the shoreline between tides. Several variants of PTD exist, yet all variants serve to limit private ownership. The version arising from Anglo-Amer- ican common law creates duties and responsibilities on the sovereign to maintain and pre- serve assets in public trust. We consider various types of geoengineering to protect example assets currently under PTD, finding a compelling case for action in a variety of contexts. This introduces a paradoxical situation, where it may theoretically be easier to compel states to undertake geoengineering to protect a beach, than to protect the whole planet. We note that, whilst PTD obligations are atomised in nature, the inherent commonality of the threat po- tentially serves to reduce this fragmentation, and to encourage common action amongst states. However, we note the failure of recent legal proceedings, which exposes practical lim- itations on the ability of PTD to compel climate action generally – and thus its applicabili- ty to geoengineering. I. Introduction – SRM: Solar Radiation Management is a suite of techniques based on the principle of modifying The difficulties in swiftly decarbonising the global the Earth’s radiation balance through partial re- economy have resulted in a renewed consideration flection of sunlight. Advocates of SRM suggest var- of geoengineering as an alternative and supplement ious schemes: marine cloud brightening (MCB); to mitigation and adaptation. In its modern usage, cirrus cloud thinning (CCT); and stratospheric geoengineering is understood to mean the deliberate aerosol injection (SAI). The resulting SRM-modi- modification of the climate system. Geoengineering fied climate would either be drier, or warmer, than has two key strands: the pre-industrial world. Furthermore, warming is – CDR/GGR: Carbon Dioxide Removal relates to re- not the only severe risk from CO2 emissions (e.g. moval of atmospheric CO2 – directly, or indirectly ocean acidification is also a major threat). More- (e.g. by treating seawater). The set of technologies over, there are major risks and controversies which known as Greenhouse Gas Removal (GGR)2 addi- make policymakers reluctant to deploy SRM at tionallyincludesremovalofsecondaryGreenhouse present.4 Gases (GHGs), such as methane, and halocarbons. Cost is the major impediment to CDR deployment When the term geoengineering is used without clar- 3 (50 EUR/ton CO2 is suggested by IEAGHG ). ification in this article, it should be taken to refer to DOI: 10.21552/cclr/2020/2/4 3 International Energy Agency Greenhouse Gas R&D Programme (IEAGHG), ‘Potential for Biomass CO Capture and Storage’ * Andrew Lockley, CPM, UCL Bartlett. Gideon Futerman, Im- 2 (eenews, 6 July 2011) <https://www.eenews.net/assets/2011/08/ manuel College. D’Maris Coffman, CPM, UCL Bartlett. For Cor- 04/document_cw_01.pdf> accessed 28 June 2020. resspondence: <[email protected]> 4 Other authors have provided helpful summaries of relevant 1 National Academy of Sciences, Climate Intervention: Reflecting arguments and literature, in the field of SRM governance. See Sunlight to Cool Earth, (National Academies Press: Washington, only J L Reynolds, ‘Solar Geoengineering to Reduce Climate DC 20001, 2015); J G Shepherd et al, ‘Geoengineering the Cli- Change: A Review of Governance Proposals’ (2019) 475 Proceed- mate: Science, Governance and Uncertainty’ (Royal Society: ings of the Royal Society A: Mathematical, Physical and Engineer- London 2009). ing Sciences 2229, 20190255; J A Flegal et al, ‘Solar Geoengi- 2 G Lomax et al, ‘Reframing the Policy Approach to Greenhouse neering: Scientific, Legal, Ethical, and Economic Frameworks’ Gas Removal Technologies’ (2015) Energy Policy 78, 125–136. (2019) 44 Annual Review of Environment and Resources 1. 86 CCLR 2|2020 both SRM and CDR. With the exception of afforesta- Future deployment of geoengineering may be tion initiatives and suchlike, to date no large-scale made by commercial firms,11 or by states and their geoengineering has been deployed. Nevertheless, ex- proxies. Likewise, two models for the possible future perts concur that neither CDR nor SRM are likely to commercial commissioning of geoengineering exist pose insurmountable engineering challenges.5 How- – depending on whether states, or private citizens ever, some forms, e.g. space mirrors, are currently and firms, are the ultimate customers.12 prohibitively expensive.6 An important risk of SRM is the threat of ‘termi- Despite the absence of historical deployments, nation shock’. This would occur if the deployment geoengineering has a prominent place in current were to be interrupted,13 due to the short lifetime of global warming discourses and debates. CDR, in par- SRM aerosols. Abrupt SRM termination is danger- ticular, is becoming embedded in major internation- ous, as the rate of increase of global temperature is a al agreements as the third leg of the mitigation, adap- major risk factor for the biosphere.14 Accordingly, tation, geoengineering tri-partite response to climate regulatory processes and procedures for SRM must change. The recent Paris treaty projects large-scale ensure that any exit from a programme is orderly and CDR deployment in the latter half of the 21st centu- thus does not expose the climate to avoidable risk of ry.7 Conversely, SRM is not part of the current poli- termination shock. One viable method for achieving cy mix. This may well change, as SRM techniques this is a smooth transition to CDR. In this case, SRM can be rapidly and inexpensively deployed. SRM is simply acts as a bridge, constraining temporary tem- also cost effective,8 with estimates of operational perature rises, whilst CDR deployment is awaited. costs as little as $1bn/yr to deliver a 1 W m−2 solar SRM is not a homogenous commodity and one ki- flux change; with the upper bound for deployment lo of injection is not automatically equivalent to an- costs being, according to McClellan, a little more than other. Various classes of SRM are fundamentally dif- $2 billion USD per year9. Another study has the fig- ferent: SAI is more long-lasting; MCB is more tem- 15 ure for halving the temperature change at between porarily and spatiallyPowered by TCPDF (www.tcpdf.org) controllable. There also ex- $2 billion and $2.5 billion USD10. These estimates ists the less well studied cirrus cloud thinning.16 SAI could potentially be reduced significantly by deliv- is much more persistent than is MCB (approximate- www.lexxion.eu ery via drone aircraft, and similar automation else- ly two years vs. days). SAI deployments are global in where in the supply chain; drone technologies are effect, tending to be spread rapidly on zonal winds,17 evolving quickly, although the authors are not aware and spread more slowly poleward by the Brewer-Dob- of calculations regarding this at present. Either way, son circulation.18 SAI broadly remains within the direct costs of SRM are negligible as a percentage of Northern or Southern hemisphere, according to the global GDP. locus of injection.19 5 Royal Society, ‘Geoengineering the Climate: Science, Gover- 13 K McCusker, et al, ‘Rapid and Extensive Warming Following nance and Uncertainty’ (Royal Society, 2020) <https:// Cessation of Solar Radiation Management’ (2014) 9 Environmen- royalsociety.org/~/media/Royal_Society_Content/policy/ tal Research Letters 2, 024005. publications/2009/8693.pdf> accessed 10 February 2020. 14 D MacMartin et al, ‘Solar Geoengineering to Limit the Rate of 6 K Schrogl and L Summerer, ‘Climate Engineering and Space’ Temperature Change’ (2014) 372 Philosophical Transactions of (2016) Acta Astronautica 129, 121–129. the Royal Society A: Mathematical, Physical and Engineering Sciences 2031), 20140134–20140134. 7 S Lewis ‘The Dirty Secret of the Paris Climate Deal’ (Foreign Policy, 17 December 2015) <https://foreignpolicy.com/2015/12/ 15 J Latham, ‘Amelioration of Global Warming by Controlled En- 17/the-dirty-secret-of-the-paris-climate-deal-carbon-capture hancement of the Albedo and Longevity of Low-level Maritime -negative-emissions-global-warming/> accessed 20 May 2016. Clouds’ (2002) Atmos Sci Lett 3, 52–58. 8 J McClellan, D Keith and J Apt, ‘Cost Analysis of Stratospheric 16 D L Mitchell and W Finnegan, ‘Modification of Cirrus Clouds to Albedo Modification Delivery Systems’ (2012) 7 Environmental Reduce Global Warming’ (2009) 4 Environmental Research Research Letters 3, 034019. Letters 4, 045102. 9 ibid 17 C Brühl et al, ‘Stratospheric Sulfur and its Implications for Radiative Forcing Simulated by the Chemistry Climate Model EMAC’ (2015) 10 W Smith and G Wagner, ‘Stratospheric Aerosol InJection Tactics 120 Journal of Geophysical Research: Atmospheres 5, 2103–2118. and Costs in the First 15 Years of Deployment’ (2018) 13 Environ- mental Research Letters 12, 124001. 18 D Keith, ‘Photophoretic Levitation of Engineered Aerosols for Geoengineering’ (2010) 107 Proceedings of the National Acade- 11 A Lockley, ‘Licence to Chill’ (2016) 18 Environmental Law my of Sciences 38, 16428–16431. Review 1, 25–40. 19 J Haywood et al, Asymmetric Forcing from Stratospheric Aerosols 12 A Lockley, ‘State Procurement of Geoengineering,
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