The White House Office of Science and Technology Policy (OSTP) has released a 5-year research plan for solar radiation management (SRM), also known as solar geoengineering. The plan is a response to a 2022 Congressional mandate directing OSTP to “provide guidance on transparency, engagement, and risk management for publicly funded work in solar geoengineering research.”
SRM refers to a group of approaches that can artificially cool the planet by reflecting incoming solar radiation back into space. The document outlines a potential research agenda to “advance understanding of the processes underpinning SRM and expected SRM deployment outcomes,” the report says.
The report focuses on two main SRM approaches: stratospheric aerosol injection and marine cloud brightening. In the former, sulfate particles are injected into the stratosphere to replicate the global cooling that occurs after volcanic eruptions. The latter uses sea salt to increase the reflectivity of low-lying clouds over the ocean.
Neither approach comes without risks. Although evidence suggests SRM could cool the planet, the report points out that it could have unintended consequences, such as changes in precipitation and biodiversity. It could also have societal and geopolitical ramifications, many of which are poorly understood.
“These unknowns, and the ever-evolving understanding of complex Earth systems, provide a compelling case for research to better understand both the potential benefits and risks,” the report says.
Although the report signals White House support for SRM research, it “does not signify any change in policy or activity by the Biden-Harris Administration,” OSTP says in an accompanying statement. “There are no plans underway to establish a comprehensive research program focused on solar radiation modification.”