Publications
Global Freight Transport Emissions Responsibility, 2024 (Environmental Science and Technology) with Jacob Fry, Keiichiro Kanemoto, & Keisuke Nansai [paper]
The transportation of freight by land, sea and air underpins the complex network of global trade in physical commodities. Greenhouse gas emissions from freight transportation are a significant component of global emissions and are predicted to grow in coming decades. However, the inclusion of freight transport in emissions accounts and environmental impact studies is often incomplete. Both data availability and difficulties in allocating freight emissions to specific commodity trades contributes to this. In this study, international freight movements by transport mode are estimated from the bottom-up by imputing global freight transport routes. Emissions are estimated from these freight movements and integrated with a global multiregional input–output model. This enables the calculation of carbon footprints that are complete with respect to freight emissions. We estimate that global freight transport emissions contributed 2.8 Gt CO2-equiv in 2012, or about 41% of total transport emissions. In general, freight footprints contribute about 9% to national emissions footprints. While trade in physical commodities (such as construction materials, food and fossil fuels) are associated with the largest embodied freight emissions, services (such as public administration, education and health) also require significant freight transport. Using a consumption-based allocation of freight transport emissions allows the decarbonisation of other sectors to be complementary to the decarbonisation of transport through reduction in demand, for example through material efficiency strategies. To drive decarbonisation in maritime transport it is critical to include bunker emissions in national emissions inventories, thereby completing the system boundary.
Net-zero targets for investment portfolios: an analysis of financed emissions metrics, 2023 (Energy Economics) with ​Tanya Fiedler [paper, appendix]
Financial institutions and investors aligning their investments with the objectives of the Paris Agreement, implementing the Task Force on Climate Disclosure recommendations, or seeking to reduce financial risks arising from the transition to a low-carbon economy, frequently measure, report, and set reduction targets for the emissions associated with their investments—called their ‘financed emissions.’ In this paper, we analyse the relationships between reductions in financed emissions and reductions in physical atmospheric emissions. We find that, unlike country-level GHG targets, reductions in a portfolio’s financed emissions has little direct relation to changes in physical emissions; over a 95% reduction in financed emissions can be achieved using industry-standard methods even while physical emissions from a portfolio’s companies are increasing. This creates a substantial risk of misaligning portfolios—and investment decisions—to climate mitigation efforts and net-zero commitments. We analyse the different financed emission definitions and targets currently in use and suggest alternative means by which investors can credibly align their portfolios with the transition to a low-carbon economy.
Climate reform and transitional industry assistance: Windfall profits for polluters?, 2023 (Energy Economics) with Gordon Leslie and Jonathan Kuok [paper]
Introducing climate change policies such as carbon pricing can bring substantial costs for fossil-fuel- fired electricity generators, with incumbents often granted a transitional allocation of free emission permits. The free allocation of emission permits and the passthrough of carbon prices to higher electricity prices has created substantial concern that these policies allow emissions-intensive firms to reap windfall profits. We use the implementation and later repeal of Australia’s price on carbon to show that coal-fired plants which received free permits had a substantial increase in their profits. This result supports calls for any transitional climate policy assistance to be tied to passthrough rates in order to avoid creating wealth transfers from taxpayers to emission-intensive generator owners.
Success, Failure, and Information: How Households Respond to Energy Conservation Goals, 2023 (Journal of the Association of Environmental and Resource Economists) [paper, appendix]
This paper investigates how households respond to repeated energy conservation goals. I track households’ program participation and electricity use decisions across successive annual energy conservation challenges offered by a large electrical utility company. I find that households’ decisions whether to re-enroll in the program and attempt a subsequent goal are highly sensitive to their success or failure in achieving their energy conservation goal, but not to the financial incentive to continue participating or to their level of past effort. This suggests that households are either responding to the emotional and normative aspects of success and failure, or are substantially inattentive to information that is provided directly to them. I also find that households’ electricity use reduces each year they participate, yet rebounds when they stop participating.
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Working papers and works in progress
Transition Risks with Carol McAusland
The ongoing transition to a low-carbon economy creates transition risks and opportunities for firms. We show that emission intensity is an insufficient predictor of a firm’s transition risk; other factors are also critical, including market structure, where emissions are released in the value chain, and the drivers of decarbonization—whether driven by costly regulations or productivity-enhancing innovation. Modelling a supply chain with Melitz-type industries, we show that high emissions do not necessarily translate to high transition risks. Moreover, commonly used risk metrics can misclassify some firms as vulnerable when they might actually benefit from economy-wide decarbonization. We outline conditions under which a firm’s Scope 1, 2, and 3 emissions accurately reflect its risk. We also identify scenarios in which aggregating these different emissions scopes enhances (or obscures) the true picture of a firm’s transition risk. Our paper lays out a framework for evaluating and improving the wide variety of transition-risk metrics currently used to guide investor decisions, inform stakeholders, and comply with climate-risk disclosure mandates.
​Complements or Substitutes? The Importance of Mode Choice In International Trade with Scott Orr​
This paper considers how substitutable transport modes are within international trade. We first show that a variety of different trade models incorporating multiple transportation modes produce the same general equation for mode-specific bilateral trade, and this imposes potentially unrealistic restrictions on trade substitution across modes and countries. In particular, we show previous trade models have implicitly treated transport modes as both substitutes and complements. By exploiting idiosyncratic variation in freight rates, we then estimate the degree of substitution between transport modes. Contrary to previous work, we find relatively little evidence of short-run substitution between air and ocean transport modes.
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Drivers of peak demand: how electrifying transportation affects peak electricity demand with Kelly Neill and Chia-jung Yeh
Power Outages, Subsidies, and the Adoption of Household Batteries in California with Andrea La Nauze
Are​ all emissions created equal? with Carol McAusland
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Physics Publications
J.A.J. Burgess, A.E. Fraser, F. Fani Sani, D. Vick, B.D. Hauer, J.P. Davis, M.R. Freeman “Quantitative Magneto-Mechanical Detection and Control of the Barkhausen Effect” Science 339, 2013
J.P. Davis, D. Vick, P. Li, S.K.N. Portillo, A.E. Fraser, J.A.J. Burgess, D.C. Fortin, W.K. Hiebert and M.R. Freeman. “Nanomechanical Torsional Resonator Torque Magnetometry” Journal of Applied Physics 109, 07D309, 2011
D. Vick, V. Sauer, A.E. Fraser, M.R. Freeman, & W.K. Hiebert. “Bulk Focused Ion Beam Fabrication With 3-Dimensional Shape Control of Nanoelectromechanical Systems” Journal of Micromechanics and Microengineering 20, 105005, 2010
N. Liu, F. Giesen, M. Belov, J. Losby, J. Moroz, A.E. Fraser, G. McKinnon, T.J. Clement, V. Sauer, W.K. Hiebert & M.R. Freeman. “Time-Domain Control of Ultrahigh-Frequency Nanomechanical Systems” Nature Nanotechnology 3, 715 - 719, 2008