21 Items

Clouds in a blue sky

Flickr CC/arbyreed

Journal Article - Science

Social Science Research to Inform Solar Geoengineering

    Authors:
  • Tyler Felgenhauer
  • William A. Pizer
  • Massimo Tavoni
  • Mariia Belaia
  • Mark E. Borsuk
  • Arunabha Ghosh
  • Garth Heutel
  • Daniel Heyen
  • Christine Merk
  • Juan B. Moreno-Cruz
  • Jesse L. Reynolds
  • Katharine Ricke
  • Wilfried Rickels
  • Soheil Shayegh
  • Wake Smith
  • Simone Tilmes
  • Jonathan B. Wiener
| Nov. 12, 2021

Professors David Keith and Joseph Aldy and their co-authors say deeper social science research could contribute to policy decisions on this tool to address climate change.

Audio - Harvard Environmental Economics Program

How Politics Impacts Climate Policy: A Conversation with Gernot Wagner

| June 08, 2021

Gernot Wagner, Clinical Associate Professor at New York University and former economist at the Environmental Defense Fund, shared his thoughts on the impact of politics on climate policy in the latest episode of “Environmental Insights: Discussions on Policy and Practice from the Harvard Environmental Economics Program,” a podcast produced by the Harvard Environmental Economics Program.

Report - Harvard Project on Climate Agreements

Governance of the Deployment of Solar Geoengineering

The Harvard Project on Climate Agreements has released a volume of 26 briefs that explores a range of topics related to how we might govern the deployment of solar geoengineering.

Earthrise over the Moon

NASA/Bill Anders

Journal Article - Nature Sustainability

Policy Design for the Anthropocene

    Authors:
  • Thomas Sterner
  • Edward B. Barbier
  • Ian Bateman
  • Inge van den Bijgaart
  • Anne-Sophie Crépin
  • Ottmar Edenhofer
  • Carolyn Fischer
  • Wolfgang Habla
  • John Hassler
  • Olof Johansson-Stenman
  • Andreas Lange
  • Stephen Polasky
  • Johan Rockström
  • Henrik G. Smith
  • Will Steffen
  • James E. Wilen
  • Francisco Alpízar
  • Christian Azar
  • Donna Carless
  • Carlos Chávez
  • Jessica Coria
  • Gustav Engström
  • Sverker C. Jagers
  • Gunnar Köhlin
  • Åsa Löfgren
  • Håkan Pleijel
  • Amanda Robinson
| 2019

The authors examine the complexities of designing policies that can keep Earth within the biophysical limits favorable to human life.

View of the crescent moon through the top of the earth's atmosphere. Photographed above 21.5°N, 113.3°E by International Space Station crew Expedition 13 over the South China Sea, just south of Macau (NASA image ID: ISS013-E-54329).

NASA

Discussion Paper

Governance of Highly Decentralized Nonstate Actors: the Case of Solar Geoengineering

| November 2018

We here introduce the idea of highly decentralized solar geoengineering, plausibly done in form of small high-altitude balloons. While solar geoengineering has the potential to greatly reduce climate change, it has generally been conceived as centralized and state deployed. Potential highly decentralized deployment moves the activity from the already contested arena of state action to that of environmentally motivated nongovernmental organizations and individuals, which could disrupt international relations and pose novel challenges for technology and environmental policy. We explore its feasibility, political implications, and governance.

Sunset on the Indian Ocean

NASA

Journal Article - Environmental Research Letters

Stratospheric Aerosol Injection Tactics and Costs in the First 15 Years of Deployment

| 2018

We review the capabilities and costs of various lofting methods intended to deliver sulfates into the lower stratosphere. We lay out a future solar geoengineering deployment scenario of halving the increase in anthropogenic radiative forcing beginning 15 years hence, by deploying material to altitudes as high as ~20 km. After surveying an exhaustive list of potential deployment techniques, we settle upon an aircraft-based delivery system. Unlike the one prior comprehensive study on the topic (McClellan et al 2012 Environ. Res. Lett. 7 034019), we conclude that no existing aircraft design—even with extensive modifications—can reasonably fulfill this mission. However, we also conclude that developing a new, purpose-built high-altitude tanker with substantial payload capabilities would neither be technologically difficult nor prohibitively expensive. We calculate early-year costs of ~$1500 ton−1 of material deployed, resulting in average costs of ~$2.25 billion yr−1 over the first 15 years of deployment. We further calculate the number of flights at ~4000 in year one, linearly increasing by ~4000 yr−1. We conclude by arguing that, while cheap, such an aircraft-based program would unlikely be a secret, given the need for thousands of flights annually by airliner-sized aircraft operating from an international array of bases.

earth

Shutterstock

News - Harvard Project on Climate Agreements

Harvard Project Conducts Research Workshop on Governance of Solar Geoengineering

| Oct. 26, 2018

The Harvard Project on Climate Agreements conducted a research workshop, “Governance of the Deployment of Solar Geoengineering,” September 27 – 28, 2018 at Harvard Kennedy School. Harvard’s Solar Geoengineering Research Program collaborated and provided support for the workshop. 

Discussion Paper - Harvard Project on Climate Agreements

An Economic Anatomy of Optimal Climate Policy

| August 2018

The authors introduce geoengineering into an optimal control model of climate economics. Together with mitigation and adaptation, carbon and solar geoengineering span all possible climate policies. Their wildly different characteristics have important implications for policy. They show in the context of their model that: (i) whether emissions are positive or zero the optimal carbon tax always equals the marginal cost of carbon geoengineering; (ii) the introduction of either form of geoengineering leads to higher emissions yet lower temperatures; (iii) in a world with above-optimal cumulative emissions, mitigation alone is insufficient and only a complete set of instruments can minimize climate damages.

This is an updated version of a paper first published in July 2017.

Inspiration Point, Canada

Wikimedia CC/Allysa Felix

Journal Article - Economic Letters

Potentially Large Equilibrium Climate Sensitivity Tail Uncertainty

| July 2018

The authors reply to Cox et al. (2018), Nature 553 (7688), 319–322. Equilibrium climate sensitivity (ECS), the link between concentrations of greenhouse gases in the atmosphere and eventual global average temperatures, has been persistently and perhaps deeply uncertain. Its "likely" range has been approximately between 1.5 and 4.5 degrees Centigrade for almost 40 years (Wagner and Weitzman, 2015). Moreover, Roe and Baker (2007), Weitzman (2009), and others have argued that its right-hand tail may be long, "fat" even. Enter Cox et al. (2018), who use an "emergent constraint" approach to characterize the probability distribution of ECS as having a central or best estimate of 2.8℃ with a 66 percent confi dence interval of 2.2–3.4℃.