News25th September 2025

Nuffield Council on Bioethics begin work to explore the ethical considerations and health-related impacts of Solar Radiation Management

The Nuffield Council on Bioethics is launching a project to identify the ethical considerations associated with Solar Radiation Management and make recommendations for the governance of research and development.

The environment & healthClimateGeoengineeringGlobal health

Solar Radiation Management (SRM) – also known as solar geoengineering – refers to a range of emerging interventions aimed at reflecting sunlight away from the earth’s surface to reduce global temperatures and counteract the effects of climate change. Examples of interventions include marine cloud brightening, where sea particles are sprayed from ships to enhance the reflectivity of low-lying clouds, and stratospheric aerosol injection, where particles are released into the stratosphere to reflect fractions of incoming sunlight.

SRM also holds potential to reduce the risk of reaching climate ‘tipping points’ – critical thresholds that, if crossed, could trigger abrupt or irreversible changes to the environment. However, interventions raise significant ethical questions, including possible health risks from exposure to toxic particles, the intensification of droughts or floods, and potential ‘termination shock’ – a rapid climate shift that could occur if SRM were suddenly halted. It is therefore important to consider the ethical trade-offs that may exist in both pursuing or not pursuing SRM research.

Our new project aims to provide an independent and balanced ethical analysis of SRM across the research lifecycle – from funding through to design and delivery – and explore the conditions under which any future use might be justified, if at all. The project will be delivered in two phases, and we expect to publish findings in full by early 2027.

Our work will begin with an ethical review that will build on our previous report. The review will identify and analyse existing SRM technologies and their ethical and health implications for human and non-human species, as well as future generations. Alongside this, we will also engage with expert stakeholders to map current research activity in a UK context, as well as with international audiences, allowing us to complement ongoing research in the area.

We will then build on our findings to address gaps in ethical oversight and produce actionable recommendations and guidance for researchers, funders and regulators. Our project aims to ensure that ethics is effectively embedded into SRM research and development, and that any future exploration is conducted responsibly.

With ongoing debate around whether to pursue Solar Radiation Management research, it is critical we address any gaps in ethical oversight. We look forward to building on existing work in this area, and hope that our project will provide useful insights on how best to practically embed ethics into decision-making about this area of research and development going forward.”

Maili Raven-Adams, Senior Researcher