Top scientists advise European Commission on solar radiation modification technologies

Brussels, 09 December 2024
A group of leading scientists nominated by academies has provided advice to the European Commission about solar radiation modification technologies through the Scientific Advice Mechanism. This advice underscores that solar radiation modification technologies are not yet mature and deploying them could have many effects, both intended and unintended.
The Scientific Advice Mechanism provides independent scientific evidence and policy recommendations to the European institutions.
For decades, technologies have been proposed that would reduce or counteract global warming by reflecting sunlight away from the Earth. These proposals, known as “solar radiation modification” technologies, include stratospheric aerosol injection, cloud brightening, and others.
However, none of the technologies is mature and deploying them could have many effects, both intended and unintended. They could have negative impacts on ecosystems, change rainfall patterns, and hamper food production. Moreover, they would not address the direct impacts of greenhouse gases.
The benefits and risks of these proposals are also highly uncertain. Member of the Group of Chief Scientific Advisors, Prof. Nebojsa Nakicenovic, adds that “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.”
“These climate interventions could present grave risks if they are ever deployed, or come to be relied upon to protect critical habitats—coral reeds, Arctic and Antarctic ice sheets, farmland key to food security—by lowering temperatures in a world of global warming” says Prof. Benjamin Sovacool, co-chair of the SAPEA working group. “Our Evidence Review Report synthesises the vast evidence on these controversial options, with a wonderful inclusion of work in the social sciences, arts, and humanities” – he adds.
Some solar radiation modification applications would need to run for generations-long timescales and have impacts across the entire planet. A strong global governance framework would be needed for this, with adequate representation for all affected parties, and with compensation mechanisms for those potentially harmed. No such framework exists, and it is not clear how one could be created.
Background
The Scientific Advice Mechanism provides independent scientific evidence and policy recommendations to the European institutions by request of the College of Commissioners. It includes the Science Advice for Policy by European Academies (SAPEA) consortium, which gathers expertise from more than 100 institutions across Europe, and the Group of Chief Scientific Advisors (GSCA), who provide independent guidance informed by the evidence.
The European Group on Ethics in Science and New Technologies (EGE) is an independent, multi-disciplinary body appointed by the President of the European Commission, which advises on all aspects of Commission policies and legislation where ethical, societal and fundamental rights dimensions intersect with the development of science and new technologies.
Within the Scientific Advice Mechanism, SAPEA is funded by the European Union. The activities of associated partners Academia Europaea and Cardiff University are funded by UKRI (grant number 10033786).
More information
Scientific Advice Mechanism, Group of Chief Scientific Advisors, Solar Radiation Modification, Scientific Opinion No. 17.
Scientific Advice Mechanism, Science Advice for Policy by European Academies, Solar Radiation Modification, Evidence Review Report.
European Group on Ethics in Science and New Technologies, Solar Radiation Modification, Ethical perspectives, Opinion No. 34.
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