The planet is hot and getting hotter. But while most plans to use geoengineering to alter the weather have been rather hypothetical, now a pair of Harvard engineers have announced that they intend to spray thousands of tons of particles into the sky to block the sun's rays—within the coming year.
The pair plan to launch a balloon to ascend 80,000 feet over Fort Sumner, New Mexico, before pumping out tens or hundreds of kilograms of sulphate aerosols into the sky. The idea is that the particles will reflect sunlight back into space, helping decrease the temperature of the Earth.
In theory, they're replicating the effects they've observed as volcanoes spew out similar sulphates into the atmosphere. In practice... well, there is no practice, because nobody's ever done it before. David Keith, one of the scientists, explained to the Guardian:
"The objective is not to alter the climate, but simply to probe the processes at a micro scale. The direct risk is very small."
Yeah, right. But however confidently he says that, in reality he doesn't know. It's hardly surprising, then, that the plan has its fair share of opposition, from scientists who believe that the experiment could have unpredictable—and therefore quite possibly negative—effects. Still, that doesn't seem to bother Keith or his partner James Anderson too much. In fact, they're keen to push forward with the project and plan to put it into action within the next twelve months.
While the experiment may not harm the climate, environmental groups say that the global environmental risks of solar geoengineering have been amply identified through modelling and the study of the impacts of sulphuric dust emitted by volcanoes.
"Impacts include the potential for further damage to the ozone layer, and disruption of rainfall, particularly in tropical and subtropical regions – potentially threatening the food supplies of billions of people," said Pat Mooney, executive director of the Canadian-based technology watchdog ETC Group. "It will do nothing to decrease levels of greenhouse gases in the atmosphere or halt ocean acidification. And solar geoengineering is likely to increase the risk of climate-related international conflict – given that the modelling to date shows it poses greater risks to the global south."
A scientific study published last month concluded that solar radiation management could decrease rainfall by 15% in areas of North America and northern Eurasia and by more than 20% in central South America.
Last autumn, a British field test of a balloon-and-hosepipe device that would have pumped water into the sky generated controversy. The government-funded project – Stratospheric Particle Injection for Climate Engineering (Spice) – was cancelled after a row over patents and a public outcry by global NGOs, some of whom argued the project was a "Trojan horse" that would open the door to full-scale deployment of the technology.
Keith said he opposed Spice from the outset because it would not have improved knowledge of the risks or effectiveness of solar geoengineering, unlike his own experiment.
"I salute the British government for getting out and trying something," he said. "But I wish they'd had a better process, because those opposed to any such experiments will see it as a victory and try to stop other experiments as well."
The Guardian understands that Keith is planning to use the Gates-backed fund to organise a meeting to study the lessons of Spice.
In truth, it's difficult to decide if the idea is a good one or not. It's easy to speculate about how effective geoengineering projects can be without ever actually putting one into action. So in that sense, it's good to see someone bite the bullet and give it a try—here's hoping it works out.