A leading geoengineering researcher has admitted that if mankind was ever forced to deploy solar management radiation techniques, it would be a sign of failure.
Mathew Wattson, a University of Bristol scientist who led one of the first experiments taking solar radiation management technology from a laboratory to real-life settings, spoke ahead of an event held by the Royal Society in London to discuss three recently concluded geoengineering research projects.
His experiment, called SPICE (Stratospheric Particle Injection for Climate Engineering), aimed to use a stratospheric weather balloon to inject 150 litres of piped water into the atmosphere to simulate cooling effects of volcanic eruptions. However, the experiment was cancelled in May over an alleged conflict of interest.
“I think if we ever deploy SRM (solar radiation management) it will be the closest indication yet that we've failed as planetary stewards,” he said.
"I believe that. It's a watershed for our relationship with the Earth and with nature. It fundamentally changes the way seven billion people are going to interact with the world, and I'm not sure the system is going to be controllable in the way we want."
Researchers study different approaches to SRM designed to reduce the amount of solar radiation reaching the Earth's surface, thus balancing out the warming caused by rising concentrations of greenhouse gases. In addition to water droplets, some have proposed using sulphur particles or bleaching clouds with salt to make them more reflective.
The techniques, although not likely to be deployed in the next few years, have slowly moved from the realm of scary science-fiction to a possible necessity as evidence keeps pouring in that barely reducing carbon emissions may not be enough.
Earlier this month, the International Energy Agency warned that despite the massive development in renewable energy generation, the world is on track to see the average global temperature rising by almost 4°C – well above the 2°C threshold deemed safe to prevent widespread consequences.
"Unless we're very wrong about climate change or quickly change our ways, at some point we're going to have to 'go outside'," Watson said,
However, the researchers believe a careful evaluation of possible side effects of such interventions would be necessary to make sure the effects themselves are not even more harmful than the greenhouse gases.
Other projects discussed during the Royal Society meeting were the IAGP (Integrated Assessment of Geoengineering Proposals) led by Professor Piers Forster from Leeds University, and Climate Geoengineering Governance (CGG) project, carried out by an Oxford University team headed by Professor Steve Rayner.
The researchers mostly agreed that solar radiation management techniques, though quite easy to implement, may have unpredictable consequences – unlike carbon capture and storage projects which pose considerable technology challenges but are easier to control.
"Our research shows that the devil is in the detail,” said Prof Forster. “Geoengineering will be much more expensive and challenging than previous estimates suggest and any benefits would be limited."
While solar radiation management may be decades away, carbon capture and storage is slowly finding its way into the green technology mainstream. Yesterday, the UN Economic Commission for Europe (UNECE) called for a strategic plan for carbon capture and storage commercialisation to be made an integral part of the new climate change treaty to be negotiated in Paris next year. The proposal envisions carbon capture and storage technology to be supported by incentives and subsidies, similarly to renewable energy generation.