The development of geoengineering techniques to curb climate change by reflecting sunlight back into space does not justify cutting more conventional efforts such as lowering greenhouse-gas emissions, an international report has found.
Instead, it says, more research is needed to assess the feasibility, risks and impacts of such techniques.
The report, “Solar Radiation Management: the governance of research”, was published on 1 December by an international group, the Solar Radiation Management Governance Initiative, which includes the Royal Society and the Academy of Science for the Developing World.
Several techniques to manipulate solar radiation have previously been suggested, including giant space mirrors and spraying sun-blocking aerosols into the atmosphere.
In the UK, the Stratospheric Particle Injection for Climate Engineering project, which was due to begin in October, has been delayed. One of the funders, the Engineering and Physical Sciences Research Council, said it needed “time for more engagement with stakeholders”.
The report finds that although SRM technologies could be a quick and relatively cheap fix for climate problems, they are “poorly understood, have the potential to be dangerous and there are risks associated not only with deployment but also medium and large-scale research”.
However, it says, a ban on “all SRM-related research would be difficult if not impossible to enforce.
“The range of SRM research runs from computer simulations and laboratory studies right up to potentially risky, large-scale experiments in the real world,” reads the report. “While most SRMGI participants were comfortable with low risk research, there was much debate over how to govern any research outside the lab.”
Although governance arrangements for managing any potentially risky research are needed, it says, a “one size fits all” approach is inappropriate.
Instead, it suggests, a “differentiated regulatory and governance approach is likely to be more effective”.
The report stresses that the SRMGI convening organisations “neither support nor oppose solar geoengineering”, but think further debate is needed.
“Unless the apparent lack of political will to significantly reduce greenhouse gas emissions changes soon, geoengineering may be needed and SRM methods could be used in unregulated and possibly reckless ways by individuals, corporations or individual countries,” said John Shepherd, co-chair of SRMGI, in a statement.
“The question of whether solar geoengineering will prove to be helpful or harmful will largely depend on how humanity can govern the issue and its political implications, and avoid unilateral action,” he added.
Recommendations in the report include the outcomes of a two-day summit at the Royal Society’s Kavli conference centre in March.