Amid growing frustration over the slow pace of global action to limit greenhouse gas emissions, attention is turning to geoengineering to reflect sunlight away from the planet – but scientists warn that such tinkering could have dramatic and unpredictable side effects.
No solar radiation modification (SRM) technologies are sufficiently mature to allow for their safe deployment, scientists have warned, prompting calls for the European Commission to commit to pursuing a global non-use agreement.
SRM covers a range of largely theoretical approaches, from releasing reflective aerosols directly into the stratosphere to injecting salt spray to increase the reflectivity of, or ‘brighten’, low-lying marine clouds.
In reports delivered today by the EU’s Scientific Advice Mechanism, leading experts in the field cautioned the Commission over the science and the ethics of using, or even counting on, such approaches.
“Deploying them could have effects on the climate in different parts of the world which would be difficult to predict and difficult to manage in practice,” said Nebojsa Nakicenovic, a member of the EU’s seven-strong Group of Chief Scientific Advisors.
Benjamin Sovacool, co-chair of the working group behind the reports, was more specific, warning that such interventions could have “negative impacts on ecosystems, change rainfall patterns, and hamper food production”.
“Moreover, they would not address the direct impacts of greenhouse gases, such as ocean acidification or changes in vegetation patterns,” Sovacool added.
Chair of the European Group on Ethics, Barbara Prainsack, pointed to an inherent danger in relying on what are essentially untested technological fixes to reverse global heating at some future point.
“Even if some of these proposals could address the symptoms of climate change, they do not address the cause, and presenting them as solutions could damage the efforts that are already underway to reduce greenhouse gas emissions and adapt to climate change,” Prainsack said.
