Initial reflections on the new Royal Society report “Geoengineering the climate: Science, governance and uncertainty”

After many months’ hard work, the Royal Society’s much-anticipated report on geoengineering was published today.  Aimed at presenting “an independent scientific review of the range of methods proposed [for geoengineering the climate] with the aim of providing an objective view on whether geoengineering could, and should, play a role in addressing climate change, and under what conditions,”  it provides what is perhaps the most authoritative and comprehensive assessment of the options to date…

I suspect that, like most climate change-related reports these days, “Geoengineering the climate: Science, governance and uncertainty” will have ideologues on both sides of the aisle up in arms.  It dares to consider the option of actively engineering the climate on a planetary scale to curb the impacts of global warming, and advocates further research into geoengineering.  In doing so, it will no doubt simultaneously enrage deniers of anthropogenic climate change, and those who fervently maintain that technological fixes are not the solution to the consequences of humanity’s excesses.

Yet for anyone mature enough to consider the merits of evidence-based and socially-responsive decision-making, the report offers a clear and insightful perspective.

From the outset, the report presents geoengineering as a far from ideal but perhaps necessary option to curbing global warming.  In the foreword, Lord Rees – President of the Royal Society – stresses that “nothing should divert us from the main priority of reducing global greenhouse gas emissions.”  Even more strongly, the top headline message of the report states

“The safest and most predictable method of moderating climate change is to take early and effective action to reduce emissions of greenhouse gases.  No geoengineering method can provide an easy or readily acceptable alternative solution to the problem of climate change.”

Yet, as the report’s authors point out, neither can we afford to be complacent in assuming that global emissions of greenhouse gases will be curbed sufficiently to avoid widespread economic, social and political impacts over the coming decades.  In the event that active interventions are needed, the report’s subtext is clear: we will need to face the scientific, social and political challenges up-front, openly and honestly if we are to have a hope of making smart decisions.

By taking a balanced and systematic approach, the report establishes a strong technical and social framework for assessing geoengineering options.  On a scientific and technical level, two classes of geoengineering approaches are identified: Carbon Dioxide Removal (CDR) techniques, and Solar Radiation Management (SRM) techniques.  Each class is addressed separately in the report.  Within these two classes, nine plausible geoengineering “solutions” are explored and assessed: biochar, enhanced weathering, carbon dioxide air capture, ocean fertilization, surface albedo alterations (urban and desert), cloud albedo modification, stratospheric aerosols and space reflectors.  These are evaluated in terms of their effectiveness, affordability, timeliness and safety.

The report summarizes the assessment of each solution in a useful graphical representation (shown below), which also includes three additional technologies not discussed extensively in the text (afforestation, carbon capture and storage at source – CCS – and bioenergy with carbon storage, or BECS).

Preliminary overall evaluation of geoengineering techniques, from the Royal Society report Geoengineering the Climate, Sept 1 2009

Preliminary overall evaluation of geoengineering techniques, from the Royal Society report Geoengineering the Climate, Sept 1 2009

While the numbers assigned to effectiveness, affordability, safety and timeliness are somewhat qualitative (hence the error bars – which merely denote large uncertainties), this representation gives a sense of which geoengineering approaches might be the more promising ones.  In crude terms, the ideal method would be represented by a large green circle to the upper right of the chart.  Under these criteria, using stratospheric aerosols to scatter sunlight away from the earth comes closest to the ideal.

Interestingly, the recently-publicized approach of painting roofs white (and other urban surface albedo raising ideas) doesn’t fare too well in this assessment. Using biochar to sequester carbon dioxide is also surprisingly low  against all four criteria.  However, while this visualization may be useful for getting a feel for the pros and cons of different geoengineering options, the report cautions that diagrams like this are “no more than preliminary and approximate and should be treated as no more than a preliminary and somewhat illustrative attempt at visualising the results of the sort of multi-criterion evaluation that is needed” to make sense of complex and uncertain geoengineering options.

Beyond the technical options for geoengineering, a substantial portion of the report is dedicated to addressing societal issues.  Chapter 4 establishes a discussion framework that includes governance of geoengineering in the light of risk and uncertainty, ethical issues, oversight of research and development, public and civil society engagement, and economic factors.  These issues are approached with seriousness and respect, and exert a strong influence over the report’s subsequent recommendations.  It is telling that the report’s authors acknowledge that

“The greatest challenges to the successful deployment of geoengineering may be the social, ethical, legal and political issues associated with governance, rather than scientific and technical issues.”

The report winds up with seventeen recommendations, ranging from the development and deployment of specific geoengineering solutions, to global governance and public engagement.  These should be read and digested in their entirety by anyone interested in geoengineering, in the context of the full report, and so I’m not going to regurgitate them here wholesale.  But I did want to highlight a few of the recommendations that I suspect will strike a particular chord with proponents and opponents of geoengineering, and anyone in the business of making tough decisions on the best way forward.  They also give a good feel for the tone and emphasis of the report:

1.1 Parties to the UNFCCC should make increased efforts towards mitigating and adapting to climate change and, in particular to agreeing to global emissions reductions of at least 50% of 1990 levels by 2050 and more thereafter.  Nothing now known about geoengineering options gives any reason to diminish these efforts. [emphasis added]

1.2 Emerging but as yet untested geoengineering methods such as biochar and ocean fertilisation should not be formally accepted as methods for addressing climate change under the UNFCCC flexible mechanisms until their effectiveness, carbon residence time and impacts have been determined and found to be acceptable.

3.1 Geoengineering methods are not a substitute for climate change mitigation, and should only be considered as part of a wider package of options for addressing climate change.  CDR methods should be regarded as preferable to SRM methods as a way to augment continuing mitigation action in the long term.  However, SRM methods may provide a potentially useful short-term backup to mitigation in case rapid reductions in global temperatures are needed.

5. The Royal Society, in collaboration with other appropriate bodies, should initiate a process of dialogue and engagement to explore public and civil society attitudes, concerns and uncertainties about geoengineering as a response to climate change.  This should be designed so as to a) Clarify the impact that discussions of the possible implementation of geoengineering may have on general attitudes to climate change, adaption and mitigation; b) Capture information on the importance of various factors affecting public attitudes, including: novelty/familiarity, scale of application and effect, aesthetics, the actors involved, centralization of control, contained versus dispersed methods and impacts, and the reversibility of effects; c) Provide participants with objective information as to the potential role of geoengineering within the broader context of climate change policies, the difference between CDR and SRM, and their relative risks and benefits.

6.1 The governance challenges posed by geoengineering should be explored in more detail, and policy processes established to resolve them.

7.1 The Royal Society in collaboration with international scientific partners should develop a code of practice for geoengineering research and provide recommendations to the international scientific community for a voluntary research governance framework.  This should provide guidance and transparency for geoengineering research and apply to researchers working in the public, private and commercial sectors.  It should include a) consideration of what types and scales of research require regulation including validation and monitoring; b) the establishment of a de minimis standard for regulation of research’ c) guidance on the evaluation of methods including relevance criteria, and life cycle and carbon/climate accounting.

On a first reading, this is a balanced, sober and authoritative report on the development and deployment of geoengineering options to address climate change.  It clearly lays out the technical approaches available, and provides a robust expert perspective on their relative merits.  But its strength lies in the broader social, ethical and political framework within which it positions these options.

The result is a report that neither promotes or denigrates geoengineering, but takes a long hard look at how to ensure the safest and most effective use of geoengineering, should it become necessary.

It’s too early to say whether this will be a truly seminal report in the history of managing global climate change – although my money is on it having a significant and lasting impact.  But it is certainly a considered and mature report. And it clearly establishes the need to take geoengineering – and all of its social, ethical and political ramifications – seriously.

The question is, are we mature enough to act on it?

Inevitably, time and consequences will tell…

Download the full report: Geoengineering the climate: science, governance and uncertainty [PDF, 4756 kb]

Related blogs:

Geoengineering: Does it need a dose of geoethics?

Geoengineering goes mainstream

Steve Chu’s White Revolution

Geoengineering: Are we grown up enough to handle it?

Geoengineering options: Balancing effectiveness and safety

Update 9/3/09 – the figure above has been updated to reflect a typograpical correction made to the original (the top right effectiveness/affordability tag was incorrect).  Thanks to everyone who pointed the error out – and to the RS for fixing it so fast!

Andrew Maynard