Stratospheric Controlled Perturbation Experiment (SCoPEx)

SCoPEx is a scientific experiment to advance understanding of stratospheric aerosols that could be relevant to solar geoengineering. It aims to reduce the uncertainty around specific science questions by making quantitative measurements of some of the aerosol microphysics and atmospheric chemistry required for estimating the risks and benefits of solar geoengineering in large atmospheric models. SCoPEx will address questions about how particles interact with one another, with the background stratospheric air, and with solar and infrared radiation. Improved understanding of these processes will help answer applied questions such as, is it possible to find aerosols that can reduce or eliminate ozone loss, without increasing other physical risks? 

At the heart of SCoPEx is a propelled scientific balloon that can travel a few meters per second (walking speed) relative to the surrounding air. The propellers serve two functions. First, the propellor wake forms a well mixed volume (roughly 1 km long and 100 meters in diameter) that serves as an experimental ‘beaker’ in which we can add gasses or particles. Second, the propellers allow us to fly the gondola back and forth through the volume to measure the properties of the perturbed air.

The advantage of the SCoPEx propelled balloon is that it allows us to create a small controlled volume of stratospheric air and observe its evolution for (we hope) over 24 hrs. Hence the acronym, Stratospheric Controlled Perturbation Experiment. If we used an aircraft instead of a balloon, we would not be able to use such a small perturbed volume nor would we be able to observe it for such long durations. 

SCoPEx builds on four decades of research on the environmental chemistry of the ozone layer in the Anderson/Keith/Keutsch groups. SCoPEx will use or adapt many of the high-performance sensors and flight-system engineering experience developed for this ozone research. Analyzing these experiments will improve our knowledge beyond what is currently available within computer models or is measurable with confidence under laboratory conditions.

Click here to learn more about SCoPEx.

Weatherhead Center for International Affairs - Solar Geoengineering Initiative

Harvard’s Weatherhead Center for International Affairs has awarded a grant to researchers in the Keith Group to support a new Initiative that will address some of the pertinent questions about climate change that fall outside the confines of the natural sciences, such as implications for politics, governance, economics, security, game theory, and more. By addressing these global topics, the research team hopes to fill in gaps in the existing literature. The team will focus on solar geoengineering. The goal of this Initiative is to build a vibrant, interdisciplinary research community at Harvard with sharply divergent positions on geoengineering. The Initiative features several Harvard-based sub-projects, each involving a few different investigators. These sub-projects will explore different dimensions of geoengineering through case studies, experiments, and theoretical modeling. Project-related talks, presentations, and discussion groups will be held at the Weatherhead Center each semester to share research findings. Each sub-project team will publish a peer-reviewed research article, which will be included in a larger edited volume with additional project findings.

Solar Geoengineering Research Residency (July 11-22, 2016, Cambridge, MA)

This summer Harvard held a two-week research residency for young scholars engaged in natural and social scientific research on solar geoengineering. The residency brought together a small number (10-15) of early-career researchers to collaborate on projects of their choosing with fellow attendees, Harvard faculty and staff, and specially invited visitors. Attendees worked together in an informal, intellectually stimulating environment designed to break down disciplinary boundaries in order to advance research on solar geoengineering across new territory.

Investigating the Response of Sea-Level Rise to Solar Geoengineering

The Harvard Climate Solutions Fund, a research fund which supports research into innovative approaches to addressing climate change, has awarded the Keith Group $100k to investigate the response of sea-level rise to solar geoengineering. Peter Irvine, a postdoctoral fellow in the Keith Group, will lead the work on this project. Sea-level rise is driven by the thermal expansion of the oceans and the melting of glaciers and ice-sheets, so it seems reasonable to presume that less warming will reduce sea-level rise regardless of whether that is due to emissions cuts or solar geoengineering. However, solar geoengineering would also affect precipitation directly, which adds mass to glaciers and ice-sheets, and would change patterns of circulation, potentially bringing warmer air and water masses into contact with the ice-sheets and glaciers. The Keith Group is evaluating the uncertainties in the response of sea-level rise to solar geoengineering and determine whether solar geoengineering could be optimized to more effectively reduce sea-level rise.

Workshop: Designing Procedural Mechanisms for the Governance of Solar Radiation Management Field Experiments (February 23-24, 2015, Ottawa)

This workshop brought together a small group of climate engineering governance experts, experienced research funding and environmental regulatory practitioners, and potential field experimentalists to explore a range of design criteria for EAs and research registries that could satisfy governance objectives. The goal was to provide a concrete and evaluated set of mechanism options for consideration by decision-makers that may be faced with SRM field experiment proposals.

The workshop report is now available.

Earthworks Unlimited: Problems and Prospects of Geoengineering (April 16-17, 2015, Cambridge, MA)

Geoengineering, a suite of technologies aimed at mitigating the potentially catastrophic consequences of climate change through deliberate human intervention, has attracted wide attention and given rise to sharply polarized debate. Proponents argue that prudence calls for these technologies to be rapidly developed, through appropriate forms of research and experimentation; opponents point to the troublesome ethical and political implications of imposing uncertain solutions on a culturally heterogeneous and economically and technologically unequal planet. Despite their global implications, geoengineering debates have remained sequestered in relatively few European and North American centers, and serious cross-disciplinary conversation is still in its infancy. This workshop brought together scholars from different regions and from fields including science and technology studies, political science, law and engineering to address the following major questions:

  1. What is at stake in geoengineering controversies and what accounts for differences across nations and regions?
  2. What specific issues are raised by geoengineering as a site of public experimentation?
  3. At what scales should the governance of geoengineering be imagined, and using what kinds of material and social infrastructures?
  4. How does geoengineering engage with ideas and practices of global constitutionalism?

Solar Geoengineering Research Residency (May 25-June 5, 2015, Cambridge, MA)

The purpose of this program was to bring together a select group of natural and social scientists to collaborate on important and intriguing questions in the field of solar geoengineering. Researchers participating in the program were not tasked with pursuing particular lines of inquiry; rather, they were free to investigate issues of their own choosing in collaboration with fellow attendees.