Geoengineering, which includes spraying sea salt or sulphate aerosols into the atmosphere to reflect sunlight, won’t provide a “magic bullet” to combat climate change, a University of Oxford study shows.
It’s too soon to judge the costs and benefits of these concepts, Steve Rayner, the James Martin Professor of Science and Civilization at Oxford, said today in a statement issued jointly with the universities of Leeds and Bristol. The cost estimates for major projects are unrealistic, he said, after looking at the governance and regulatory hurdles associated with geoengineering.
“Take everything you hear both for and against geoengineering with a large grain of salt,” said Rayner, the principal investigator for the Climate Geoengineering Governance project. “It’s almost certain that geoengineering will be neither a magic bullet nor Pandora’s Box.”
The British universities are considering ways of manipulating temperatures through geoengineering as the International Energy Agency estimates that investment in low-carbon power and energy efficiency needs to more than double to $790 billion by 2020 to keep global warming within safe margins.
In the Bristol university study, sulphate aerosols were sprayed into the atmosphere to reflect more sunlight back into space. It’s a process that naturally occurs when particles are emitted from volcanic eruptions.
“Whilst it’s clear that temperatures could be reduced during deployment, the potential for misstep is considerable,” said Matthew Watson, a reader in natural hazards from the University of Bristol. “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.”
The Leeds study found that only a few clouds were “susceptible” after spraying sea salt to brighten them to reflect more light.