New Research Examines Potential for Using Solar Engineering to Mitigate Climate Risk

December 19, 2013
By Doug Gavel, HKS Communications

With significant political, environmental and economic hurdles standing in the way of an international agreement to reduce carbon emissions, there is growing urgency to learn of the potential for other measures to mitigate the effects of global warming.

In a new research paper titled, "Climate Policy Under Uncertainty: a Case for Solar Geoengineering," Harvard Kennedy School Professor David Keith and co-author Juan B. Moreno-Cruz of the Georgia Institute of Technology construct a simple model to examine some of the policy implications for solar radiation management (SRM), a technique for blocking incoming sunlight in order to reduce atmospheric temperatures.
“We introduce SRM in a simple economic model of climate change that is designed to explore the interaction between uncertainty in the climate’s response to CO2 and the risks of SRM in the face of carbon-cycle inertia,” the authors write.

"As a simple way to capture climate-carbon inertia we use a two-stage decision framework in which the abatement decisions are made in the first period and SRM decisions are made in the second. In between periods, the decision maker learns the true sensitivity of the climate."

Through their analysis, the authors identify two significant findings:

  • Imperfect SRM is an effective means to manage the uncertainty in the climate response because it can be implemented quickly after this uncertainty is resolved, providing a tool to manage the inertia in the carbon-climate decision problem. Without SRM, the existence of high-consequence low-probability climate impacts, combined with the irreversibility of emissions, may force very high levels of abatement and hence high costs; and
  • Learning about SRM — that is the value of information associated with reducing the uncertainty about the side-effects of SRM — can reduce the overall costs of climate change in the order of 10%, depending on the amount of learning.

The authors admit that the model used is highly simplified, however, "the limitations of the model likely do not affect its main result; that is, SRM is valuable for managing climate risk, not because of its low cost, but because it can be implemented quickly if we discover that climate impacts are high, a 'climate emergency.'"

The paper was published in the December 2013 edition of Climatic Change.

David Keith, professor of public policy

David Keith, professor of public policy

“We introduce solar radiation management (SRM) in a simple economic model of climate change that is designed to explore the interaction between uncertainty in the climate’s response to CO2 and the risks of SRM in the face of carbon-cycle inertia,” the authors write.

 


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