It sounded like an odd but harmless experiment. Last October British scientists planned to send a balloon more than half a mile high to spray water into the air. Yet a few days before the test, it was delayed amid major backlash from environmental groups.
Though the trial itself would surely have been safe, it was a step toward something far more controversial: geoengineering, the use of large-scale human intervention to reverse the effects of climate change. Instead of water, the researchers envision that their balloon may one day release tons of particulates that would reflect sunlight and cool the planet.
But judging by the reaction to the pilot experiment, geoengineers will need to employ a delicate public relations strategy as they pursue their research. The Stratospheric Particle Injection for Climate Engineering, or SPICE, project entered the public eye last summer when scientists trumpeted the $200,000 balloon experiment at the British Science Festival. The announcement generated interest but also pushback. A Canadian environmental group sent a letter warning of drought resulting from the future release of sun-blocking particles and claiming that the test would cause a distraction from international efforts to cut greenhouse gas emissions.
Other scientists in the field, meanwhile, fear the public rebuke will make it harder for them to run their own experiments. “I would like to see them withdraw the test,” says David Keith of the Harvard Kennedy School, who has testified before Congress about geoengineering. He argues that SPICE should focus on assessing risks of particle dispersion rather than testing equipment. “We need to have legitimate discussion about concerns without having the debate framed around the safety of small experiments, which is not the root issue,” he says.
For now, SPICE scientists are retreating to lab research and engaging the public, including groups such as Greenpeace. They still plan to launch that balloon, however, perhaps as early as this month. “I don’t want to have to do geoengineering,” says Hugh Hunt, the University of Cambridge engineer who devised the test. “But if my house were on fire, I’d like to think that a fire engine has already been designed.”