Geoengineering is not going away any time soon. It is beginning to move from a fringe topic into the mainstream, and a genuine research community is starting to set the agenda for future research. ‘Climate engineering’ or ‘geoengineering’ is an umbrella term covering methods by which humans can modify Earth’s climate: carbon dioxide removal (CDR) or decreasing the amount of incident solar radiation (solar radiation management; SRM). In August 2011 the Banff Centre in Canada hosted the Second Transdisciplinary Summer School on Climate Engineering. The aim of the summer school was to develop interdisciplinary research skills and to bring together the younger members of the nascent research community.
Currently the geoengineering discourse is monopolised by a few. In the words of the school’s organiser David Keith, ‘the same people keep popping up’. It is never healthy to have a field dominated by a small group of people, no matter how individually brilliant and well-meaning they may be. The summer school sought to provide students with the tools to get involved in the discourse. A strong research community helps us get our research right; that means it must be timely, transparent and relevant. This requires information exchange between natural scientists, social scientists, policymakers and the general public.
The central problem of geoengineering (especially by SRM) is that of risk analysis. Conventionally we might weigh cost against benefit. However, according to David Keith there are some geoengineering schemes which can be viewed as essentially costless. For example, injecting aerosols into the stratosphere would cost (Robock et al 2009) tens of billions of US dollars per year. In this case monetary cost is not the limiting factor in decision-making and the trade-off is between the risks of action and the risks of inaction. These risks can operate on different spatial and temporal scales, and also on different groups. For the sake of argument, imagine that not injecting aerosols poses a low risk (from climate change) to economically developed countries through loss of key port cities; and that injecting aerosols poses a high risk to regions of Africa relying on monsoon rainfall for their agriculture. The rational risk-risk decision would be not to act, but the more powerful influences could decide to act and maximise their self-interested benefits. The challenge of geoengineering governance is to ensure decisions reflect the interests of all parties and not just influential minorities.
Prof. Granger Morgan also spoke about analysis of climate risk. Conventional risk analysis involves putting a value on positive and negative effects and making a decision based on the balance of these effects. This involves certain assumptions:
- There is a single decision-maker.
- The values we hold are known and static.
- The decision-maker maximises utility.
- There are manageable impacts which can be valued.
- The discount rate (the rate at which the future is considered to be ‘irrelevant’) is exponential – that is, the future becomes increasingly ‘worthless’.
- The system is linear and predictable.
Morgan emphasised that none of these assumptions were satisfactory when considering either geoengineering or climate change. He asked whether we were deluding ourselves into certainty using cost-benefit analysis on a problem where it was not appropriate. The question still stands.
So what are the risks? Here is David Keith’s offering, in order of severity:
- Conflict. Our technology for developing reflective aerosols is advancing rapidly and the cooling potential is very high. SRM also acts very quickly, with cooling happening within months. Finally, the impacts will be felt more in some areas of the globe than others. These three factors suggest a high risk of conflict over SRM technology. SRM was in an ideal world is relatively safe, but adding in human conflict and folly the worst-case SRM scenario is at least as bad – or perhaps worse – than unmitigated anthropogenic climate change.
- Accelerating the end of nature. Once humanity has the ability to control the amount of solar radiation incident on the planet, it is on a slippery slope towards planetary management. The temptation to attempt to fine-tune aspects of the Earth system to our own profit will be strong. The evidence from case studies of human management of planetary systems suggests we might not do a good job.
- Moral hazard. Having the option of fast-acting SRM may reduce the public and political will to take the long, slow path of emissions reduction. It does not matter that SRM is an incomplete solution as long as the perception is that it would offer an easy way out.
- Environmental risks. These include ozone depletion, impacts on tropospheric clouds from aerosol particles settling out of the stratosphere and impacts on the global hydrological cycle. Keith did not dismiss these risks, but claimed they were relatively small and could be dealt with. Hence they were his least important concern.
These risks are at the core of decision making regarding geoengineering, and researchers from a wide range of disciplines are beginning to unpick them. The process of guiding scientific research may soon become more formalised as a result of a programme governing geoengineering research. This was a common item on the ‘wish list’ of many at the summer school – a global programme managing research goals. We might also expect ethical norms to be developed, much like there have been in stem cell research.
Such a programme would be able to co-ordinate research efforts to answer key scientific questions. Two questions I noticed being asked repeatedly concerned the identification of climate tipping points (could SRM be implemented in a ‘climate emergency’, and would be know it if we were in one?) and the regional climate impacts of SRM technology. These are the two areas where climate scientists can bring their expertise to bear. There is, however, one more important role scientists can play: that of the rational sceptic. There are many people out there who are losing their heads over geoengineering. Either they think it is fundamentally evil, or they think it is something we should be doing right now. It is easy for voices of caution and reason to get lost in the hubbub.
What the future holds
Geoengineering is an expression of a problem humanity has struggled with since it developed organised societies. How do we manage our impact on the Earth system? Initially it started out as small-scale resource management, such as crop rotation to avoid soil degradation. Then we effected regional environmental change through deforestation. Now we have the technology to affect the entire planet. The question for the future is: what is our place on this Earth?
A population of humans inevitably shapes its environment to suit its needs, but until now this has been on a relatively small scale (sub-global) or an unintentional side-effect. This might change in the future as we understand the magnitude of our potential impacts on the Earth system. This Pandora’s Box, once opened, will never be shut. We must learn to deal with that which is contained within.