Confronting the abatement paradox Integrating aerosol cooling within climate change mitigation policy Justin Wood BSc, BAppSc, MSc is thesis is presented for the degree of Doctor of Philosophy of Murdoch University 2013 Discipline of Physics and Energy Studies School of Engineering and Information Technology I declare that this thesis is my own account of my research and contains, as its main con- tent, work that has not been previously submied for a degree at any tertiary education institution. Supervisors: Prof. Philip Jennings and Adam McHugh, with assistance from Dr August Schläpfer. Produced in the open-source LYX editor and Zotero bibliographic management soware. Typeset in LATEX and XƎTEX with the open-source fonts Linux Bolinum, Linux Libertine, and Fontin Sans. My sincere gratitude to the LYX user community, Jürgen Spitzmüller in particular, and to Petr Šimon for LyZ, his invaluable Zotero–BIBTEX–LYX integration tool. e author’s original work is licensed under Creative Commons. All other material remains copyright of the authors and their publishers. Acknowledgements My sincere gratitude and appreciation goes to my principal supervisors, Philip and Adam, for their wisdom and their forbearance. August provided welcome advice and enthusi- asm. I thank Prof. Tom Lyons for early review of the physical science material (remain- ing mistakes or omissions are mine alone). I can scarcely thank Dr Cecily Scu enough, for without her support, guidance, concern, and when needed, cajoling, this thesis would simply never have been completed. And my dear friend Dr Beth Gouldthorp, for her unending encouragement and understanding. I wish to recognise those that led or helped me to begin this doctorate, oen unbe- knownst to them: David Spra, whose book Climate code red seeded the idea that we need to talk about aerosols; James Hansen, for his indefatigable courage, determination, and insight; RealClimate.org, for teaching us all; and to my friend Glenn, who once told me that he had never regreed any decision to just take the leap. And finally, to my friends and family, for puing up with me thus far. Contents Abstract 1 1 Introduction and overview 5 1.1 e aerosol dilemma ............................. 5 1.2 On avoiding dangerous interference ..................... 8 1.3 Research questions .............................. 14 1.4 Methodology .................................. 16 1.4.1 Research approach .......................... 16 1.4.2 esis structure ............................ 17 1.4.3 Nomenclature ............................. 18 2 Aerosol effects on climate 19 2.1 Physical characteristics ............................ 20 2.1.1 Formation and composition ..................... 20 2.1.2 Mixing state .............................. 20 2.1.3 Atmospheric residence time and emissions ............. 21 2.1.4 Atmospheric distribution ...................... 22 2.1.5 Perturbation baseline ......................... 23 2.2 Optical and radiative properties ....................... 24 2.2.1 Particle effective radius ........................ 24 2.2.2 Absorption, scaering, and extinction coefficients ......... 25 2.2.3 Asymmetry parameter ........................ 26 2.2.4 Single scaering albedo ....................... 26 2.2.5 Aerosol optical depth ......................... 27 2.3 Radiative forcing ................................ 29 2.3.1 Forcing efficacy ............................ 33 2.4 Species ..................................... 34 2.4.1 Natural aerosols ............................ 35 2.4.2 Anthropogenic aerosols ....................... 35 2.5 Climatic effects and influence ........................ 46 2.5.1 Direct radiative effect ........................ 47 2.5.2 Indirect cloud albedo effect ...................... 51 2.5.3 Indirect cloud lifetime effect ..................... 54 i Contents 2.5.4 Semi-direct effect ........................... 57 2.5.5 ermodynamic effect ........................ 62 2.5.6 Glaciation effect ............................ 63 2.5.7 Biomass fertilisation effect ...................... 64 2.5.8 in Arctic cloud ........................... 65 2.5.9 Longwave absorption effect ..................... 66 2.5.10 Further effects on climatic processes ................ 66 2.5.11 Effects on surface irradiance ..................... 68 2.5.12 Summary of effects .......................... 73 2.6 Synthesis and implications .......................... 75 2.7 Observation and modelling .......................... 79 2.7.1 Observation and measurement ................... 79 2.7.2 Aerosol modelling .......................... 83 3 Climate response and associated risk 95 3.1 Climate response to forcing .......................... 95 3.1.1 Radiative forcing revisited ...................... 96 3.1.2 Equilibrium climate sensitivity ................... 98 3.2 Planetary energy imbalance and climate response ............. 99 3.2.1 antitative estimates of energy imbalance and aerosol forcing . 103 3.3 Commied warming ............................. 109 3.3.1 Derived climate response function ................. 110 3.4 Dangerous anthropogenic interference ................... 113 3.4.1 Aerosol-induced temperature change ................ 114 3.5 Toward appropriate metrics ......................... 118 3.5.1 e problem with GWP and CO2-e ................. 119 3.5.2 Alternative methods ......................... 122 3.6 Aerosol emission rates ............................ 130 3.6.1 Aggregate emissions ......................... 131 3.6.2 Emissions by source ......................... 134 3.6.3 Future emissions ........................... 136 3.7 Policy implications .............................. 141 4 Comparative analysis of mitigation policy 143 4.1 Pollution taxonomy .............................. 143 4.1.1 Emission and assimilation ...................... 144 4.1.2 Atmospheric mixing ......................... 147 4.1.3 Environmental impact ........................ 148 4.1.4 Applying the taxonomy ....................... 150 4.1.5 A new term for emission sources .................. 151 ii Contents 4.2 Policy ontology and form ........................... 152 4.2.1 Less is beer ............................. 152 4.2.2 Less is worse ............................. 154 4.2.3 e policy challenge ......................... 156 4.3 A revised ontology .............................. 159 4.3.1 Clarifying effect and impact ..................... 159 4.3.2 Expanded classification schema ................... 161 4.4 Accounting for aerosols in climate change policy .............. 166 4.4.1 Linkage synergy and co-benefits .................. 166 4.4.2 Linkage barriers and conflict ..................... 167 4.4.3 Are they included currently? .................... 170 4.4.4 Could they be? ............................ 174 4.5 Confounding complexities .......................... 178 4.5.1 e problem of CO2 non-equivalence ................ 178 4.5.2 Correlated externality feedbacks .................. 179 4.6 Unintended consequences: the abatement paradox ............. 184 4.7 Dangerous omissions ............................. 186 5 Aerosol-integrated mitigation policy criteria 193 5.1 Policy objective ................................ 194 5.2 Discussion and scope ............................. 196 5.2.1 Definition of terms .......................... 197 5.2.2 Plausible compensative measures .................. 198 5.2.3 Which emissions, which sources? .................. 203 5.2.4 Measurement and reporting ..................... 206 5.2.5 How much and for how long? .................... 208 5.2.6 Temporal and spatial considerations ................ 210 5.2.7 Compensative masking services ................... 212 5.2.8 e question of accounting ..................... 213 5.2.9 Domestic implementation ...................... 216 5.3 Implementation model evaluation ...................... 218 5.3.1 Loss-liability model .......................... 219 5.3.2 Cost-neutrality model ........................ 223 5.3.3 Funding and ultimate liability .................... 226 5.3.4 Central authority model ....................... 228 5.3.5 Conferred value model ........................ 230 5.4 Ramifications for abatement pathways ................... 236 6 Scheme implementation: the balancing market 241 6.1 Restricted direct value model ......................... 241 6.1.1 Overview and rationale ....................... 242 iii Contents 6.1.2 Carbon price mechanism integration ................ 243 6.2 Scheme implementation ............................ 244 6.2.1 Licensed compensative measures .................. 246 6.2.2 Coverage and reporting liabilities .................. 247 6.2.3 antification metric ......................... 249 6.2.4 NFA emission baseline ........................ 250 6.2.5 e residual masking license .................... 252 6.2.6 Market demand ............................ 253 6.2.7 Reverse auction mechanism ..................... 255 6.2.8 Contract funding ........................... 260 6.3 Market dynamics ............................... 265 6.3.1 Price determinants .......................... 265 6.3.2 Supply shortfalls ........................... 271 6.3.3 Effect on carbon price and abatement pathway .......... 275 6.3.4 Supply excess ............................. 291 6.4 Interaction with air pollution regulation .................. 295 6.4.1 Apparent conflicts .......................... 296 6.4.2 Operational price dynamics ..................... 298 6.4.3 Targeted regulation .......................... 301 6.5 Model evaluation ............................... 302 7 Conclusions 305 7.1 Research questions revisited ........................