AN ALTERNATIVE VIEW

Peter Irvine is a climate scientist at Harvard University who researches solar geoengineering. He argues that the benefits of the technology could outweigh the risks

“THE COSTS OF GEOENGINEERING ARE LOW, ITS EFFECTS WILL BE FELT QUICKLY AND GLOBALLY”

I’ve been working since 2009 to understand the potential and limits of geoengineering, and Clive Hamilton paints a picture of this technology that I simply do not recognise. To address climate change, carbon dioxide emissions will have to be driven to zero, but however fast emissions are cut, the climate will still warm considerably over the 21st Century. It’s here that stratospheric aerosol geoengineering could prove an extremely useful tool.

Higher temperatures mean more intense heatwaves; they mean air carries more moisture, causing more intense floods; and they mean more melting of the glaciers, driving up sea levels. Reducing temperatures will reduce these risks, and our work has shown that it doesn’t make much difference whether this is done by lowering emissions or by cooling from solar geoengineering. This doesn’t mean geoengineering should be a replacement for emissions cuts – indeed, it may introduce some new risks of its own – but it would help to offset some of climate change’s worst impacts.

Clive points to the potential dangers of geoengineering reducing monsoon rainfall, but his picture is incomplete. Water availability depends not only on how much rain falls but also on how quickly it evaporates in the heat of the day. The same climate models that show that geoengineering would reduce rainfall also show that it would reduce evaporation, potentially leading to more, not less, water availability for people, crops and ecosystems.

Clive also claims that, because climate control would require detailed technical knowledge to manage, it would somehow lead to the technocrats taking over. Yet our lives depend on the technocrats who manage our electricity grids, our water supply, our transport systems and our internet, and still our societies remain robustly democratic.

Clive portrays geoengineering as an idea born of Cold War hubris and pushed by right-wing climate deniers. Instead, I see a well-intentioned proposal that is being critically evaluated by hundreds of researchers around the world, from disciplines as diverse as engineering, economics and international law. Rather than coming from shadowy right-wing think tanks of fossil-fuel interests, funding for geoengineering research comes mostly from governments (which reflects a societal demand for this knowledge) and environmentally minded philanthropists.

Outside of academia, there are also exciting developments. The Solar Radiation Management Governance Initiative is an international NGO that’s working to empower scientists and policy makers in developing countries to engage with geoengineering, while in New York, the Carnegie Climate Geoengineering Governance Initiative (led by Janos Pasztor, the former climate science adviser to Ban Kimoon) aims to bring this topic to the attention of international policy makers at the UN and beyond.

The ratification of the Paris Agreement and the stunning developments in solar and wind power in recent years show that the world has the will and is developing the tools to tackle climate change. Even so, international cooperation in this area remains a notoriously difficult process: the benefits of cutting emissions are global and will be felt in the long run, whereas the costs are felt here and now. So even though all countries agree that they want to limit the impacts of climate change, each country benefits the most by doing the least.

For geoengineering, the picture is completely different. The costs of geoengineering are low, its effects will be felt quickly, and they’ll be global in scope. This means that governments will have a real incentive to work together to realise the potential benefits of geoengineering.

So the reality of this technology is rather different from the worst- case scenario pictured by Clive Hamilton. We now need a concerted international and interdisciplinary research effort into geoengineering, and we shouldn’t let pessimistic fears get in the way of exploring an idea that might really help in the fight against climate change.

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