'More research needed in Solar Radiation Management,' says Andy Parker, SRMGI

Andy Parker is a research fellow at the Institute for Advanced Sustainability Studies and the project director for the SRM Governance Initiative (SRMGI). He has a background in climate policy and has worked on solar geo-engineering for over eight years, including as a research fellow at the Harvard Kennedy School and a senior policy adviser at the Royal Society. He was also a member of the UN Convention on Biological Diversity's expert working group on geoengineering.

<B>BR Research: How long has the idea of solar radiation management (SRM) been around? How much impetus has it gained since?</B>

<B>Andy Parker:</B> The idea has been around for several decades. When the problem of climate change was first brought to the attention of an American President - Lyndon Johnson in 1965 - solar geoengineering was suggested as a potential response. However, recent interest was sparked by a 2006 paper by Nobel laureate Paul Crutzen, which called for more research.

Now the idea is receiving more and more attention as people begin to get their heads around the concept of committed climate change - the warming to which Earth is already committed from greenhouse gases that have already been released. Solar geoengineering still remains a niche topic, even in climate circles, however.

<B>BRR: Tell us about SRMGI's funding.</B>

<B>AP:</B> The SRM Governance Initiative is funded by the Open Philanthropy Project, which is collaboration between Good Ventures and Givewell. For more information about OPP see http://www.openphilanthropy.org/, and for more information about SRMGI, you can see our website: http://www.srmgi.org/

<B>BRR: What are the different SRM methods? Are they at any stage of testing whatsoever or is that completely and entirely out of the question?</B>

<B>AP:</B> The method receiving the most attention from researchers is stratospheric aerosols. This would involve spraying reflective aerosol particles into the upper atmosphere, where they would remain for a year or two, filtering out a small percentage of inbound sunlight and cooling the planet.

The basic idea that aerosols in the stratosphere can significantly reduce global temperatures is well understood, in part because volcanoes provide us with natural experiments once in a while. In the couple of years following a very large volcanic eruption the global temperature drops, as the sulphates aerosols it blasts into the stratosphere block out a small amount of sunlight.

To date, most of the research on solar geoengineering has taken the form of 'indoor' research - computer modelling and library-based social science research. There are ongoing and active discussions on whether and how research conducted outside the laboratory should be conducted.

<B>BRR: How much literature/research exists on SRM?</B>

<B>AP:</B> There is a growing body of research on the numerous different dimensions of SRM research, from climate modelling to ethics to economics to public engagement. However, there are still many large uncertainties, and it's still too early to determine how the use of SRM would be beneficial or harmful.

<B>BRR: What are some of the side effects of SRM (acid rain, smog, affecting photosynthesis of plants, changing seasonal and cropping patterns, vitamin D reduction, etc)?</B>

<B>AP:</B> Our knowledge of the side effects of SRM is subject to the same levels of uncertainty as our knowledge of the primary effects on the climate system. Studies have indicated that using sulphur dioxide as the aerosol for filtering out sunlight could delay the regeneration of the ozone. However, a recent paper found evidence that using a different aerosol - calcium carbonate - could aid the regeneration of ozone.

Potential health impacts need to be better understood, but the use of sulphur dioxide as the aerosol would be expected to slightly increase respiratory illnesses globally, and would need to be weighed up carefully against any potential benefits of reducing the impacts of climate change.

Effects on plant life need to be much better understood.

<B>BRR: Which countries do you think stand to benefit the most from the implementation of SRM and which would lose out?</B>

<B>AP:</B> It's hard to say at this early stage, not least because modelling studies are imperfect representations of reality and they necessarily contain assumptions about how solar geoengineering would be deployed. However, modelling research has fairly consistently indicated that use of solar geoengineering could simultaneously reduce the global disruptions to temperature and hydrology that we'd expect to see from global warming. Much more research would be needed if we ever wanted to make an informed decision about this, however.