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Startups Want To Cool Earth By Reflecting Sunlight. There Are Few Rules and Big Risks

By Julia Simon, NPR

A small group of researchers on a cloudy day.
Julia Simon/NPR
Jessica Medrado, a research scientist for SRI International, on a walkie-talkie, coordinates the test for solar geoengineering research. Behind her are (center) Kelly Wanser of SilverLining, the nonprofit that led fundraising for the program, and (right) Sarah Doherty, scientist at University of Washington and the program’s director.

As the private sector grows, not-for-profit entities are speeding up their research.

Earlier this month, a handful of scientists and engineers gathered on deck of a decommissioned aircraft carrier on the San Francisco Bay to test a large machine. After about a decade of work, the researchers were readying the machine for one of its first tests outdoors, creating tiny salt water particles that could – someday – reflect sunlight and cool earth.

An engineer scooped salt into a large plastic container, mixing it with water. Then he turned the machine on, letting forth a giant hissing spray of salt water particles down the aircraft runway.

The test represents a different type of solar geoengineering than Make Sunsets’ balloons. “Marine cloud brightening” involves brightening ocean clouds to reflect more planet-heating sunlight.

This technology could someday significantly reduce many of the impacts of global warming, says Sarah Doherty, a University of Washington professor who manages this program. But it also has risks. If the particles are too big, they can make the clouds less reflective, and actually warm the planet. An imbalance of cloud brightening off West Africa could cause a drought in the Amazon. For Doherty, these unknowns are a big reason for this research.

“You could see in 20 years from now, people saying, ‘Oh my God, we’re really in trouble. We’ve got major climate disruption. Let’s do this thing that we know exists.’ Well, if we haven’t done the research to look at the ways to not do it properly, to not do it in a way that’s going to cause more damage, then we’re really in trouble,” she says.

The risks are why university researchers, not for-profit companies, should guide studies of this tech, argues Kelly Wanser, executive director of SilverLining, the nonprofit that led fundraising for Doherty’s program. The University of Washington program – which also aims to improve current climate modeling – has raised $16 million, mostly from philanthropic climate funds and Silicon Valley scientists. Doherty says there’s no strings attached. “They’re not gonna ever get anything back out of it other than more science,” she says.

Wanser contrasts this with what she calls the “misaligned incentives” of private companies entering the space. In addition to its venture capital fundraising, Make Sunsets sells “cooling credits” – a single $10 credit offsets the warming of 1 metric ton of carbon dioxide, the company says. For Wanser, for-profit companies like Make Sunsets have a monetary incentive to keep releasing balloons, even if the effects could be harmful.

Iseman responds in an email that, “All change is scary, and we can’t use ‘someday maybe’ as an excuse to avoid the bold actions that the climate crisis demands.”

But even with university-based solar geoengineering research, there’s a need for regulation, says Imran Khalid, a climate policy researcher based in Islamabad. While the aircraft carrier is a museum open to the public – a group of elementary school children came aboard a little while after the test – there are no rules requiring future research projects to be so transparent. And while this study released a small amount of particles, there are no specific regulations to limit a future study from making a larger release.

Given the stakes, Khalid says there should be global input into research frameworks. “Research leads to deployment at some time,” he says. “There needs to be a global discussion around this issue.”

See story at NPR