The Integrated Assessment of Geoengineering Proposals (IAGP) project, led by the University of Leeds, conducted an interdisciplinary study evaluating a range of expertises – climate modelling, philosophy and engineering – in addition to understanding public perceptions, to assess the effectiveness of geoengineering proposals.
The IAGP ran simulations of various geoengineering proposals, including forms of both solar geoengineering – such as reflective particles in the stratosphere, more reflective oceans, and more reflective crops –and carbon dioxide geoengineering – such as carbon dioxide capture and storage, ocean fertilisation, and afforestation – to observe how effectively each proposal achieved its desired goal.
Piers Forster, Professor of Physical Climate Change at the University of Leeds, and principal investigator of the IAGP project, said ‘Geoengineering will be much more expensive and challenging than previous estimates suggest and any benefits would be limited. For example, when simulating the spraying of sea salt particles into clouds to try to brighten them, we found that only a few clouds were susceptible and that the particles would tend to coagulate and fall out before reaching the cloud base.’
The study brings into question whether there is enough time to research the necessary technologies required in order to make geoengineering a viable option for combating climate change.
‘I don’t think we can wait to research geoengineering,’ Professor Forster told Geographical. ‘Climate change is so important an issue that we need to examine all mitigation, adaptation and geoengineering options. The more technologies that are in the public domain, the more able we are to simulate their effects and possibly rule them out. For example, we found adding reflective material to the Sahara would be very damaging – so that would be essentially a no-go.
‘I doubt the perfect technology will ever exist as there will always be winners and losers with any intervention, including mitigation,’ he continued. ‘But in my mind, it is worth researching all of them, including combinations of technologies. If our simulations of them improve enough to become trustworthy, we may need to consider deploying them one day, but only within the context of other mitigation and adaptation options. Solar methods would only ever be a short-term partial solution and are perhaps better thought as an extreme adaptation technique.’
The IAGP project was started in 2010, off the back of a 2009 Royal Society report entitled Geoengineering the climate: science, governance and uncertainty. Two other projects received funding at the same time: the Stratospheric Particle Injection for Climate Engineering (SPICE) project, led by the University of Bristol, and the Climate Geoengineering Governance (CGG) project, led by the University of Oxford.
The SPICE project used volcanoes as models to mimic the effect of a solar geoengineering proposal, in which sulphate aerosols are pumped into the atmosphere to reflect more sunlight back into space. Dr Matthew Watson, a reader in natural hazards from the University of Bristol, and principal investigator for the SPICE project, said ‘Whilst it is clear that temperatures could be reduced during deployment, the potential for misstep is considerable. By identifying risks, we hope to contribute to the evidence base around geoengineering that will determine whether deployment, in the face of the threat of climate change, has the capacity to do more good than harm.’
Meanwhile, the CGG project concentrated on the governance and regulatory challenges posed by both research and possible deployment, and came to the conclusion that geoengineering proposals that are technically the easiest to implement and have the quickest impact may be the most difficult to govern, while those that are easiest to govern seem likely to be further away from effective large-scale deployment.