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.
The advisory board also warned that SRM applications would need to run for generations and would have impacts across the entire planet, so would require a robust global governance framework with sections of the population represented and mechanisms in place to compensate those adversely affected.
“No such framework exists, and it is not clear how one could be created,” was the terse conclusion.
Moratorium
The scientific and ethical advice boards clearly recommended that the EU should focus on continued efforts at greenhouse gas reduction and climate adaptation, and announce a Europe-wide moratorium on solar radiation modification technologies – and at the same time negotiate a global governance system for future decisions on the use of such techniques.
Meanwhile, research in the area must be “rigorous, ethical and explicit about uncertainties” and take into account all direct and indirect effects along with issues of governance and justice, they said in a statement accompanying their reports, calling full a full review every five to ten years.
The Centre for Future Generations welcomed the scientists’ call for more thorough research into the effects of geoengineering. “The floods in Valencia and the lack of progress in Baku underscore the grave dangers we face as the climate unravels,” said Cynthia Scharf, a senior fellow at the Brussels-based think tank.
Deadly floods in Spain came just before the COP29 climate summit in the Azerbaijani capital last month, which ended with a deal on climate financing that civil society groups and countries in the global south saw as a case of rich industrialised countries shirking their historical responsibility to pay for the damage caused by centuries of fossil fuel use.
Civil society groups were concerned, however, that EU advisers did not go far enough in warning about the perils of tinkering with the climate.
Linda Schneider, a specialist in energy and climate policy at the Heinrich-Böll Foundation said the recommendations “do not do justice to the grave and irresolvable risks of solar geoengineering” and warned the focus on research and dialogue could serve to legitimise exploration of such interventions.
“Instead of kickstarting an open-ended negotiation process that could end up enabling solar geoengineering deployment, the European Union should work with African and Pacific governments to establish a clear and robust international non-use agreement,” Schneider said, noting that the European Parliament had already called for this in a resolution last year.
Mary Church, geoengineering campaign manager at the Center for International Environmental Law, said the call for a review every five years sent “very mixed signals” about the advisers’ commitment to preventing the use of SRM.
“The EU should rule out funding outdoor experiments. Small-scale outdoor experiments simply cannot provide meaningful information on the intended climate impact of solar geoengineering, but they do serve technology development and risk normalising these dangerous technologies,” Church said.
