Read This Now: GAO Report on Climate Engineering: Technical Status, Future Directions, and Potential Responses

Last week we revisited
the geoengineering debate in light of the recent Bipartisan Policy Center’s
report recommending that the U.S. government be prepared to counter the effects
of global climate change through climate remediation – that is, by engineering
the climate. In particular, we emphasized the need to understand the foreign
policy dilemmas that are likely to arise from engineering the global climate. This
week we turn to the technical feasibility of actually doing it.  

Later today Dr. Tim Persons, the Government Accountability
Office’s Chief Scientist and author of the latest report, Climate Engineering:
Technical Status, Future Directions, and Potential Responses, will
discuss the future of climate engineering technologies at an event at the
Wilson Center. Several of the GAO report’s findings are worth highlighting in
advance of that discussion though. According to the report:

Climate engineering technologies
are not now an option for addressing global climate change, given our
assessment of their maturity, potential effectiveness, cost factors, and
potential consequences. Experts told us that gaps in collecting and
modeling climate data, identified in government and scientific reports, are
likely to limit progress in future climate engineering research.

The report evaluated the most and least advanced options for
engineering the climate. “To assess the current state of climate engineering
technology, we rated each technology for its maturity on a scale of 1 to 9,
using technology readiness levels (TRL)—a standard tool for assessing the
readiness of emerging technologies before full-fledged production or
incorporation into an existing technology or system,” the report stated. Any
technology with a TRL score below 6 is considered immature by technical standards
and “may face challenges with
respect to potential effectiveness, cost factors, and potential consequences.”

According to the report, the highest-scoring technology with
a TRL score of 3 was “direct air capture of CO₂,” or carbon capture
and sequestration, a concept readers are likely familiar with. “Direct air
capture is believed to be decades away from large-scale commercialization,” the
report found. “Additionally, for each of the currently proposed CDR [carbon dioxide
removal] technologies, we found that implementation on a scale that could
affect global climate change may be impractical, either because vast areas of
land would be required or because of inefficient processes, high cost, or
unrealistically challenging logistics.”

Perhaps not surprisingly, solar radiation management technologies
(SRM), those that would “inject aerosols into Earth’s stratosphere to scatter a
fraction of incoming sunlight, artificially brighten clouds, place solar
radiation scatterers or reflectors in space, or increase the reflectivity of
Earth’s surface,” received TRL scores of 2 or below, with no analytical or
experimental proof of concept. Moreover, according to the report, “the SRM
technologies that we rated ‘potentially fully effective’ have not, thus far,
been shown to be without possibly serious consequences.”

What this seems to suggest is that effective climate
engineering technologies are still years away. Many of the experts that the GAO
interviewed advocated for research into climate engineering now because
procuring effective technologies could take more than twenty years. (Note: experts’
advocacy for climate engineering research was not meant as a substitute for the need to continue
to pursue strategies to reduce greenhouse gas emissions, which could nullify
the need for climate engineering solutions.)

Beyond the timing issue, the report noted important hurdles
to furthering climate engineering research. “A key challenge in climate
engineering research is safely evaluating the technologies’ potential risks in
advance of large-scale field tests or deployment,” the report stated. More
could be done to address these kinds of challenges, the GAO found:

Climate modeling would be a
helpful evaluative tool, but a number of both federal agency and scientific
reports have identified limitations in climate models and their underlying
bases. Expanded scientific knowledge, enhanced precision and accuracy of
tools for measuring key climate variables, and the development of dedicated
high-performance computing would help fill the gaps and make future research
more effective.

I have not seen any mention of climate engineering, climate
remediation or geoengineering in the budget debates on Capitol Hill. But given
the lack of support for non-discretionary science programming in general, one
has to wonder how realistic it is to expect much advanced research on climate
engineering. It will be interesting to see if any of this gains traction on the
Hill as the super committee continues its work to cut the budget.