Solar Geo-Engineering Widely Viewed as Risky Business
The somewhat sci-fi concept — to use blimps, planes, or other means to load Earth’s atmosphere with particles or droplets that reflect sunlight and cool the planet — has crept into the mainstream conversation as a means of reversing relentless climate change, should our efforts to slash carbon emissions fail or sputter.
But geoengineering schemes come with a slew of hazards. A number of studies have cited the ill consequences of messing with Earth’s sun intake, including big falls in crop production, the likelihood of unforeseen adverse side effects, and critically, a weakened water cycle that could trigger drops in precipitation and widespread drought.
Yet new research, published Monday in the journal Nature Climate Change, acknowledges these problems but finds a potential fix: only deploying enough reflective specks in the atmosphere to reduce about half of Earth’s warming, rather than relying on geoengineering to completely return Earth to the cooler, milder climate of the 19th century.
In other words, giving Earth a geoengineering dose that would reverse a significant portion of the warming, but not enough to stoke the problematic side effects.
“We wanted to clear up if some of the issues that we’ve seen were the result of doing too much geoengineering,” said Peter Irvine, a postdoctoral researcher at Harvard University’s John A. Paulson School of Engineering and Applied Sciences and lead author of the study.
In the early 2000s, the notion of geoengineering sounded like a “really outlandish idea,” Irvine admitted. But this new research, building on other studies, illustrates that such a planetary-wide undertaking — if applied cautiously, incrementally, and with careful dosing — might not be so far-fetched, after all.
“It looks like, surprisingly, it works quite well,” said Irvine. That’s not to say Irvine and his research team are promoting the idea of deploying geoengineering on the planet anytime soon.
They aren’t. Rather, this research is a piece of the puzzle that may ultimately reveal if geoengineering could work without unleashing widescale harm to the planet, particularly plunges in rainfall (in part due to reduced sunlight resulting in less energy driving rainfall and precipitation).
“I don’t think it makes any sense to do it now,” David Keith, a solar engineering researcher at Harvard University and study co-author, said. “And if it doesn’t make sense, we shouldn’t do it,” he added, noting that any geoengineering deployment would likely still be some two decades away.