Academic Publications

2016
Joshua Horton and Jesse Reynolds. 3/18/2016. “The International Politics of Climate Engineering: A Review and Prospectus for International Relations.” The Oxford University Press. Publisher's VersionAbstract

Proposed large-scale intentional interventions in natural systems in order to counter climate change, typically called “climate engineering” or “geoengineering,” stand to dramatically alter the international politics of climate change and potentially much more. There is currently a significant and growing literature on the international politics of climate engineering. However, it has been produced primarily by scholars from outside the discipline of International Relations (IR). We are concerned that IR scholars are missing a critical opportunity to offer insights into, and perhaps help shape, the emerging international politics of climate engineering. To that end, the primary goal of this paper is to call the attention of the IR community to these developments. Thus, we offer here an overview of the existing literature on the international politics of climate engineering and a preliminary assessment of its strengths and lacunae. We trace several key themes in this corpus, including problem structure, the concern that climate engineering could undermine emissions cuts, the potentially “slippery slope” of research and development, unilateral implementation, interstate conflict, militarization, rising tensions between industrialized and developing countries, and governance challenges and opportunities. The international politics of climate engineering is then considered through the lenses of the leading IR theories (Realism, Institutionalism, Liberalism, and Constructivism), exploring both what they have contributed and possible lines of future inquiry. Disciplinary IR scholars should have much to say on a number of topics related to climate engineering, including its power and transformational potentials, the possibility of counter-climate engineering, issues of institutional design, international law, and emergent practices. We believe that it is incumbent on the IR community, whose defining focus is international relations, to turn its attention to these unprecedented technologies and to the full scope of possible ramifications they might have for the international system.

Joshua Horton, David Keith, and Matthias Honegger. 2016. “Implications of the Paris Agreement for Carbon Dioxide Removal and Solar Geoengineering.” Policy Brief, Harvard Project on Climate Agreements, Belfer Center for Science and International Affairs, Harvard Kennedy School. Publisher's Version
Caitlin G. McCormack, Wanda Born, Peter Irvine, Eric P. Achterberg, Tatsuya Amano, Jeff Ardron, Pru N. Foster, Jean-Pierre Gattuso, Stephen J. Hawkins, Erica Hendy, W. Daniel Kissling, Salvador E. Lluch-Cota, Eugene J. Murphy, Nick Ostle, Nicholas J.P. Owens, R. Ian Perry, Hans O. Pörtner, Robert J. Scholes, Frank M. Schurr, Oliver Schweiger, Josef Settele, Rebecca K. Smith, Sarah Smith, Jill Thompson, Derek P. Tittensor, Mark van Kleunen, Chris Vivian, Katrin Vohland, Rachel Warren, Andrew R. Watkinson, Steve Widdicombe, Phillip Williamson, Emma Woods, Jason J. Blackstock, and William J. Sutherland. 2016. “Key impacts of climate engineering on biodiversity and ecosystems, with priorities for future research.” Journal of Integrative Environmental Sciences, Pp. 1-26. Publisher's VersionAbstract

Climate change has significant implications for biodiversity and ecosystems. With slow progress towards reducing greenhouse gas emissions, climate engineering (or ‘geoengineering’) is receiving increasing attention for its potential to limit anthropogenic climate change and its damaging effects. Proposed techniques, such as ocean fertilization for carbon dioxide removal or stratospheric sulfate injections to reduce incoming solar radiation, would significantly alter atmospheric, terrestrial and marine environments, yet potential side-effects of their implementation for ecosystems and biodiversity have received little attention. A literature review was carried out to identify details of the potential ecological effects of climate engineering techniques. A group of biodiversity and environmental change researchers then employed a modified Delphi expert consultation technique to evaluate this evidence and prioritize the effects based on the relative importance of, and scientific understanding about, their biodiversity and ecosystem consequences. The key issues and knowledge gaps are used to shape a discussion of the biodiversity and ecosystem implications of climate engineering, including novel climatic conditions, alterations to marine systems and substantial terrestrial habitat change. This review highlights several current research priorities in which the climate engineering context is crucial to consider, as well as identifying some novel topics for ecological investigation.

Joshua Horton and David Keith. 2016. “Solar Geoengineering and Obligations to the Global Poor.” In Climate Justice and Geoengineering: Ethics and Policy in the Atmospheric Anthropocene, edited by Christopher J. Preston. London: Rowman & Littlefield. Publisher's Version Horton and Keith 2016
Lee Miller and Axel Kleidon. 2016. “Wind speed reductions by large-scale wind turbine deployments lower turbine efficiencies and set low generation limits.” Proceedings of the National Academy of Sciences. Publisher's VersionAbstract

Wind turbines generate electricity by removing kinetic energy from the atmosphere. Large numbers of wind turbines are likely to reduce wind speeds, which lowers estimates of electricity generation from what would be presumed from unaffected conditions. Here, we test how well wind power limits that account for this effect can be estimated without explicitly simulating atmospheric dynamics. We first use simulations with an atmospheric general circulation model (GCM) that explicitly simulates the effects of wind turbines to derive wind power limits (GCM estimate), and compare them to a simple approach derived from the climatological conditions without turbines [vertical kinetic energy (VKE) estimate]. On land, we find strong agreement between the VKE and GCM estimates with respect to electricity generation rates (0.32 and 0.37 We m−2) and wind speed reductions by 42 and 44%. Over ocean, the GCM estimate is about twice the VKE estimate (0.59 and 0.29 We m−2) and yet with comparable wind speed reductions (50 and 42%). We then show that this bias can be corrected by modifying the downward momentum flux to the surface. Thus, large-scale limits to wind power use can be derived from climatological conditions without explicitly simulating atmospheric dynamics. Consistent with the GCM simulations, the approach estimates that only comparatively few land areas are suitable to generate more than 1 We m−2 of electricity and that larger deployment scales are likely to reduce the expected electricity generation rate of each turbine. We conclude that these atmospheric effects are relevant for planning the future expansion of wind power.

2015
Jana Sillmann, Timothy M. Lenton, Anders Levermann, Konrad Ott, Mike Hulme, Francois Benduhn, and Joshua Horton. 2015. “Climate Emergencies Do Not Justify Engineering the Climate.” Nature Climate Change. Publisher's Version
Jason J. Blackstock, Neil Craik, Jack Doughty, and Joshua Horton. 2015. “Designing Procedural Mechanisms for the Governance of Solar Radiation Management Field Experiments: Workshop Report”. Publisher's Version
Joshua Horton. 2015. “The Emergency Framing of Solar Geoengineering: Time for a Different Approach.” The Anthropocene Review. Publisher's Version
Hossein Safaei and David Keith. 2015. “How much bulk energy storage is needed to decarbonize electricity?.” Energy and Environmental Science, 8, 12, Pp. 3409-3417. Publisher's Version
Steven R. H. Barrett, Raymond L. Speth, Sebastian D. Eastham, Irene C. Dedoussi, Akshay Ashok, Robert Malina, and David Keith. 2015. “Impact of the Volkswagen emissions control defeat device on US public health.” Environmental Research Letters, 10, 11, Pp. 114005. Publisher's Version
Joshua Horton, Andrew Parker, and David Keith. 2015. “Liability for Solar Geoengineering: Historical Precedents, Contemporary Innovations, and Governance Possibilities.” NYU Environmental Law Journal, 22, Pp. 225-273. Publisher's Version
Debra Weisenstein, David Keith, and John Dykema. 2015. “Solar geoengineering using solid aerosol in the stratosphere.” Atmospheric Chemistry and Physics, 15, Pp. 11835-11859. Publisher's Version
David Keith and Douglas G. MacMartin. 2015. “A temporary, moderate and responsive scenario for solar geoengineering.” Nature Climate Change, 5. Publisher's Version
Lee Miller, Nathaniel A. Brunsell, David B. Mechem, Fabian Gans, Andrew J. Monaghan, Robert Vautard, David Keith, and Axel Kleidon. 2015. “Two methods for estimating limits to large-scale wind power generation.” Proceedings of the National Academy of Sciences of the United States, 112, Pp. 11169–11174. Publisher's Version
David Keith and Andy Parker. 2015. “Will solar geoengineering help us manage the risks of climate change?.” Our world and us: How our environment and our societies will change, Pp. 76-92. Publisher's Version
Kerry Emanuel, Frauke Hoss, David Keith, Zhiming Kuang, Julie Lundquist, and Lee Miller. 2015. “Workshop on Climate Effects of Wind Turbines, American Meteorological Society”. Publisher's Version
2014
Sebastian D. Eastham, Debra K. Weisenstein, and Steven R. H. Barrett. 2014. “Development and evaluation of the unified tropospheric–stratospheric chemistry extension (UCX) for the global chemistry-transport model GEOS-Chem.” Atmospheric Environment, 89, Pp. 52-63. Publisher's VersionAbstract

Global chemistry-transport models (CTMs) typically use simplified parameterizations or relaxation to climatology to estimate the chemical behavior of the stratosphere only in the context of its impact on tropospheric chemistry. This limits investigation of stratospheric chemistry and interactions between tropospheric and stratospheric chemistry-transport processes. We incorporate stratospheric chemical and physical processes into the model GEOS-Chem in the form of a unified chemistry extension (UCX). The stratospheric chemistry framework from NASA’s Global Modeling Initiative (GMI) is updated in accordance with JPL 10-06 and combined with GEOS-Chem’s existing widely applied and validated tropospheric chemistry to form a single, unified gas-phase chemistry scheme. Aerosol calculations are extended to include heterogeneous halogen chemistry and the formation, sedimentation and evaporation of polar stratospheric clouds (PSCs) as well as background liquid binary sulfate (LBS) aerosols. The Fast-JX v7.0a photolysis scheme replaces a hybrid of Fast-J and Fast-JX v6.2, allowing photolytic destruction at frequencies relevant to the stratosphere and of species not previously modeled. Finally, new boundary conditions are implemented to cover both surface emissions of new species and mesospheric behavior. Results for four simulation years (2004-2007) are compared to those from the original, tropospheric model and to in situ and satellite-based measurements. We use these comparisons to show that the extended model is capable of modeling stratospheric chemistry efficiently without compromising the accuracy of the model at lower altitudes, perturbing mean OH below 250 hPa by less than 5% while successfully capturing stratospheric behavior not previously captured in GEOS-Chem such as formation and collapse of the Antarctic ozone hole. These extensions (with supporting validation and intercomparison) enable an existing and extensively validated tropospheric CTM to be used to investigate a broader set of atmospheric chemistry problems and leverages GEOS-Chem’s existing tropospheric treatment.

Eastham Weisenstein Barrett 2014
David Keith, Riley Duren, and Douglas MacMartin. 2014. “Field experiments on solar geoengineering: report of a workshop exploring a representative research portfolio.” Philosophical Transactions of the Royal Society A, 372. Publisher's Version
MacMartin, D. G., B. Kravitz, and D. W. Keith. 2014. “Geoengineering: the world’s largest control problem.” American Control Conference, Pp. 2401-2406. Publisher's Version
Ben Kravitz, Douglas MacMartin, Alan Robock, Philip Rasch, Katharine Ricke, Jason Cole, Charles Curry, Pete Irvine, Duoying Ji, David Keith, Jon Egill Kristjánsson, John Moore, Helene Muri, Balwinder Singh, Simone Tilmes, Shingo Watanabe, Shuting Yang, and Jin-Ho Yoon. 2014. “A multi-model assessment of regional climate disparities caused by solar geoengineering.” Environmental Research Letters, 9. Publisher's Version

Pages