A U.K. project that is examining the feasibility of geoengineering the Earth’s climate to reduce global warming will no longer involve an outdoor experiment that was scheduled to take place later this year. The Stratospheric Particle Injection for Climate Engineering (SPICE) project was set to test the delivery of aerosols high into Earth’s atmosphere. Today, however, planners announced that they have cancelled the test because of concerns that researchers involved in the project could have a commercial interest in its success.
Funded by the U.K. government, SPICE was set up in 2010 by British research institutions to investigate whether aerosols, such as sulfate particles, could be injected into Earth’s stratosphere to scatter sunlight back into space, thereby stalling global warming. Aerosols are already known to reduce global warming: The vast clouds of sulfates thrown up in the 1991 eruption of Mount Pinatubo in the Philippines, for example, reduced average global temperatures by about half a degree Celsius. Releasing aerosols on purpose is controversial, however, so scientists are keen to understand how such geoengineering might proceed before any policy decisions are made. They would like to understand what sort of aerosols could be used, how they would impact different aspects of climate, and how they would be delivered to the atmosphere.