Final report of the FP7 CSA project EuTRACE European Transdisciplinary Assessment of Climate Engineering The European Transdisciplinary Assessment of Climate Engineering (EuTRACE) Removing Greenhouse Gases from the Atmosphere and Reflecting Sunlight away from Earth Editors: Stefan Schäfer, Mark Lawrence, Harald Stelzer, Wanda Born, Sean Low Editors: Stefan Schäfer, Mark Lawrence, Harald Stelzer, Wanda Born, Sean Low Lead authors: Paola Adriázola, Gregor Betz, Olivier Boucher, Stuart Haszeldine, Jim Haywood, Peter Irvine, Jon-Egill Kristjansson, Mark Lawrence, Tim Lenton, Helene Muri, Andreas Oschlies, Alexander Proelss, Tim Rayner, Wilfried Rickels, Lena Ruthner, Stefan Schäfer, Jürgen Scheffran, Hauke Schmidt, Vivian Scott, Harald Stelzer, Naomi Vaughan, Matt Watson Contributing authors: Asbjørn Aaheim, Alexander Carius, Patrick Devine-Right, Anne Therese Gullberg, Katherine Houghton, Rodrigo Ibarrola, Jasmin S. A. Link, Achim Maas, Lukas Meyer, Michael Schulz, Simon Shackley, Dennis Tänzler Project advisory board: Bidisha Banerjee, Ken Caldeira, Mike Childs, Harald Ginzky, Kristina Gjerde, Timo Goeschl, Clive Hamilton, Friederike Herrmann, David Keith, Tim Kruger, Doug Parr, Katherine Redgwell, Alan Robock, David Santillo, Pablo Suarez Project coordinator: Mark Lawrence The EuTRACE project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 306993. It brought together a consortium of 14 partner institutions that worked together to compile this assessment report. Consortium members represented various disciplines with expertise on the topic of climate engineering. The views expressed in this report are not necessarily representative of the views of the institutions at which the authors are employed. Citation: Schäfer, S.; Lawrence, M.; Stelzer, H.; Born, W.; Low, S.; Aaheim, A.; Adriázola, P.; Betz, G.; Boucher, O.; Carius, A.; Devine-Right, P.; Gullberg, A. T.; Haszeldine, S.; Haywood, J.; Houghton, K.; Ibarrola, R.; Irvine, P.; Kristjansson, J.-E.; Lenton, T.; Link, J. S. A.; Maas, A.; Meyer, L.; Muri, H.; Oschlies, A.; Proelß, A.; Rayner, T.; Rickels, W.; Ruthner, L.; Scheffran, J.; Schmidt, H.; Schulz, M.; Scott, V.; Shackley, S.; Tänzler, D.; Watson, M.; Vaughan, N. (2015) The European Transdisciplinary Assessment of Climate Engineering (EuTRACE): Removing Greenhouse Gases from the Atmosphere and Reflecting Sunlight away from Earth. Funded by the European Union’s Seventh Framework Programme under Grant Agreement 306993. 2_ EuTRACE Report EuTRACE is a joint project of EuTRACE Report_3 Final report of the FP7 CSA project EuTRACE Contents Preface 12 Executive Summary 13 1 Introduction 16 1.1 The context: climate change 16 1.2 Engineering the climate as a proposed response to climate change 18 1.3 Understanding climate engineering: the role of scenarios and numerical climate modelling 22 1.4 Historical context and overview of this report 25 2 Characteristics of techniques to remove greenhouse gases or to modify 27 planetary albedo 2.1 Greenhouse gas removal 27 2.1.1 Afforestation 28 2.1.2 Biomass energy with carbon capture and storage (BECCS) 28 2.1.3 Biochar 31 2.1.4 Additional biomass-based processes: non-forest, burial, use in construction, and algal 32 CO2 capture 2.1.5 Direct air capture 32 2.1.6 Enhanced weathering and increased ocean alkalinity 33 2.1.7 Ocean fertilisation, including ocean iron fertilisation (OIF) 34 2.1.8 Enhancing physical oceanic carbon uptake through artificial upwelling 36 2.1.9 Cross-cutting issues and uncertainties 37 2.1.9.1 Lifecycle assessment of greenhouse gas removal processes 37 2.1.9.2 CO2 storage availability and timescale 38 2.2 Albedo modification and related techniques 40 2.2.1 Stratospheric aerosol injection (SAI) 41 2.2.2 Marine cloud brightening (MCB) / marine sky brightening (MSB) 44 2.2.3 Desert reflectivity modification 46 2.2.4 Vegetation reflectivity modification 47 2.2.5 Cirrus cloud thinning 48 2.2.6 Results from idealised modelling studies 49 2.2.7 General effectiveness and constraints of modifying the planetary albedo 55 2.2.8 Carbon cycle climate feedbacks between modifying the planetary albedo and removing 56 greenhouse gases from the atmosphere 4_EuTRACE Report Contents 3 Emerging societal issues 58 3.1 Perception of potential effects of research and deployment 58 3.1.1 Moral Hazard 58 3.1.2 Environmental responsibility 60 3.1.3 Public awareness and perception 61 3.1.4 Participation and consultation: questions from example cases 63 3.2 Societal issues around potential deployment 70 3.2.1 Political dimensions of deployment 73 3.2.2 Economic analysis 74 3.2.2.1 Assessing costs and benefits 74 3.2.2.2 Socio-economic insights from climate engineering scenarios 76 3.2.3 Distribution of benefits and costs 77 3.2.4 Compensation 80 4 International regulation and governance 82 4.1 Emerging elements of a potential climate engineering regime in the activities of 83 international treaty bodies 4.1.1 UNFCCC – Climate engineering as a context-specific response to climate change? 84 4.1.2 LC/LP – Climate engineering as an activity or technical process? 86 4.1.3 CBD – Climate engineering judged in light of its effects on the environment? 88 4.1.4 Outlook: bringing together the regulatory approaches of context, activities and effects 89 4.2 The EU law perspective: considering a potential regulatory strategy for climate engineering 90 including application of the approaches of context, activities and effects 4.2.1 EU Primary Law – An overarching context for climate engineering regulation and 91 competences for its implementation within the EU 4.2.2 EU Secondary Law 92 4.2.3 Taking a regional perspective on climate engineering 93 EuTRACE Report_5 Final report of the FP7 CSA project EuTRACE 5 Research options 94 5.1 Background 94 5.2 Arguments for and concerns with climate engineering research 96 5.2.1 Arguments in favour of climate engineering research 96 5.2.2 Concerns with climate engineering research 97 5.3 Knowledge gaps and key research questions 98 6 Policy development for climate engineering 103 6.1 Policy context 103 6.2 General policy considerations for climate engineering 105 6.2.1 Urgency, sequencing and multiple uses of climate engineering research 105 6.2.1.1 Urgency and timeliness of climate engineering research 105 6.2.1.2 Sequencing: Advantages and disadvantages of a parallel research approach 107 6.2.1.3 Multiple uses of knowledge: Connection to other research 107 6.2.1.4 Outlook: a challenge and opportunity 108 6.2.2 Policy considerations in developing principles for climate engineering governance 108 6.2.3 Strategies based on principles 110 6.2.4 Policy considerations for international governance of climate engineering 112 6.2.4.1 The United Nations Framework Convention on Climate Change (UNFCCC) 113 6.2.4.2 The Convention on Biological Diversity (CBD) 113 6.2.4.3 The London Convention and Protocol (LC/LP) 113 6.2.4.4 Possible future development of the emerging regime complex on climate engineering 114 6.3 Technique-specific policy considerations 115 6.3.1 Policy development for BECCS 115 6.3.2 Policy development for OIF 118 6.3.3 Policy development for SAI 119 6.4 An EU perspective 122 6_EuTRACE Report Contents 7 Extended Summary 125 7.1 Introduction 125 7.2 Characteristics of techniques to remove greenhouse gases or to modify the 126 planetary albedo 7.2.1 Greenhouse gas removal 126 7.2.2 Albedo modification and related techniques 128 7.3 Emerging societal issues 129 7.4 International regulation and governance 133 7.5 Research options 134 7.6 Policy development for climate engineering 135 7.6.1 Development of research policy 136 7.6.2 Development of international governance 136 7.6.3 Development of technique-specific policy 137 7.6.4 Potential development of climate engineering policy in the EU 138 8 References 140 EuTRACE Report_7 Final report of the FP7 CSA project EuTRACE List of Figures 1.1 Observed global mean surface temperature anomalies from 1850 to 2012 17 1.2 Global surface–atmosphere solar and terrestrial radiation budget 19 2.1 Contributions of various technologies and changes in end-use to two mitigation scenarios, 29 with a significant role for BECCS assumed in both scenarios 2.2 Air–sea CO2 flux and change in flux over time induced by ocean iron fertilisation in model 35 simulations 2.3 Sizes of fossil carbon supply (reserves and resources) and potential carbon stores (in Gt CO2) 39 2.4 Surface shortwave radiative flux anomaly induced by a given annual rate of 42 injection of stratospheric sulphate particles, for three different modelling studies 2.5 Depiction of cloud brightening by aerosol particle injection 45 2.6 Schematic of cirrus cloud thinning by seeding with ice nuclei, showing reduction in reflection 48 of shortwave solar radiation and absorption of longwave terrestrial radiation 2.7 Idealised radiative forcing curves in each of the four original GeoMIP experiments (G1-G4) 51 2.8 Difference between the GeoMIP G1 simulation and the pre-industrial control simulation for 53 surface air temperature and precipitation (mean of 12 GeoMIP models) 2.9 Multi-model ensemble simulations (GeoMIP G2) of the impact on temperature due to 55 albedo modification by reduction of the solar constant 2.10 Enhanced carbon uptake due to a deployment of albedo modification (reducing global 57 average temperatures from an RCP8.5 scenario down to the pre-industrial level) 3.1 Schematic overview of possible consequences of the deployment of SAI 71 3.2 Schematic