Clouds, by reflecting sunlight, cool the land or sea below them. Whiter clouds reflect more sunlight. So, what if you could intentionally make clouds whiter?
British physicist John Latham posed that question in the early 1990s. He and University of Edinburgh engineer Stephen Salter came up with an idea of how that might be done: by blasting tiny seawater droplets into the air. But can such a machine actually be built? And would the theory work in reality?
A small group of atmospheric scientists interested in testing Latham and Salter’s idea invited retired Silicon Valley engineer (and IEEE Life Member) Armand Neukermans to meet with them about seven years ago. Neukermans knew a little something about spraying droplets; he helped develop the first generation of inkjet printers at HP. He’d previously worked at Xerox on the forerunner of the continuous inkjet—a sprayer that broke up the spray of toner into uniform droplets. “The HP inkjet wasn’t really my project,” he recalls, but after problems with printer nozzles caused a number of failures, “I made the membranes for the first prototype that worked.” Perhaps a cloud-brightening system could be something like a big inkjet nozzle.
That meeting was, essentially, the end of Neukermans’s retirement. In 2008, he brought what came to be called the Marine Cloud Brightening Project to Silicon Valley, assembled a group of tech industry veterans, moved into lab space sublet from Aqua Metrology Systems in Sunnyvale, and started working. The core developers—none younger than 70, the oldest 80—have a wealth of engineering experience. They include Gary Cooper, formerly of Syntex and Roche; Jack Foster, an early laser engineer who worked at Sandia, Sylvania, HP, and Xros; Lee Galbraith, inventor of the Surfscan for IC detection who worked at Sandia and Tencor; Suds Jain, formerly of Synoptics, Bay Networks, Broadcom, and Acterra; and Bob Ormond, formerly of Metara and now with Aqua Meteorology. That’s the engineering team. The science part of the project involves collaborators from the University of Washington’s Department of Atmospheric Sciences, the Pacific Northwest National Laboratory, and various collaborators in England.
These engineers don’t just have each other. They also are able to tap into their long-standing networks of former colleagues and friends. “This is Silicon Valley,” Neukermans says, “so when we need to make small holes, we go to the Nanolab at Stanford. We needed a diamond, we went to sp3 Diamond Technologies and they gave us flat pieces of diamond. We needed laser drilling, we knew where to go for that: DPSS Lasers.”
You need something here, you can get it. You have a question, you can find some guy that worked out an answer 20 years ago.
Being senior citizens, though, means they are past the stay-at-the-lab-all-night-drinking-energy-shots stage. They aren’t going to be in the office 24/7—or even 8/5. “This is a geriatric crew, so we only work four days a week,” Neukermans says. “And not everyone always shows up, but they do if they can.”
Still, they’ve managed to get a lot done. The key, they know, is making the droplets extremely tiny—because that way they’ll drift up into clouds instead of falling, and because they’ll be more reflective. Explains Neukermans, “If you take a glass beaker and fill it with large marbles, you can look straight through; if you make the marbles as small as sand, all the light gets reflected and it looks white, you can’t see through it.”
Initially, the group did design something like a continuous ink jet printer, with holes a thousand times smaller than a traditional ink jet. But that setup proved susceptible to a seemingly inescapable issue: If the salty water clogged just one hole, the fluid flowed irregularly into the other holes and caused problems. Now the group is developing a system that works more like a snowmaking machine, but with droplets a thousand times smaller and shooting a hundred meters into the air. The device mixes air and water precisely and blows it out of a thin nozzle. The plan is to combine hundreds of these nozzles and have them shoot tiny water droplets simultaneously.
They are planning to build five full-size machines for a test run conducted by the University of Washington’s Joint Institute for the Study of the Atmosphere and Ocean. The team is looking forward to testing the result of their work outdoors, with actual clouds. “We know this project can’t be just old guys in a garage,” says Neukermans. “We are going to deliver a prototype.”
It will take $6 million—including the cost of the water droplet blowers, the observational aircraft, and the data analysis—to complete the testing. The group is looking to raise that money from both private investment and government grants. They expect to be able to run the test within a year or two, likely somewhere on the California coast.
The engineers working on this project don’t necessarily expect it to work. But it’s worth a shot. Says Neukermans:
Globally, you have a quarter of the ocean covered with marine boundary layer clouds. If you make them six percent more reflective, that will change the reflectivity of the earth one percent, which would almost offset a doubling of carbon dioxide in terms of the heating it causes.
He’s not completely convinced that brightening every cloud over the ocean is practical. But he is more optimistic about using the technology to address problematic hotspots.
For example, “consider the coast of California in the summer. We’ve lost 35 percent of the cloud cover, and the redwoods are stressed. This could help,” he says.
“Or we might be able to locally cool the ocean over the Gulf of Florida. When Hurricane Katrina came up over the Gulf, the water was five degrees warmer than usual, which created the Cat 5 storm. What if you could prevent that?”
Neukermans makes it clear that he and his colleagues aren’t advocating geoengineering; there are a host of issues beyond the engineering of a system that would have to be addressed. But even if it’s never deployed for that purpose, the system will help scientists study clouds. (Climate scientists still have a long way to go in understanding how clouds form and contribute to climate change.)
But it’s an idea that could work, and that’s the way research goes: You formulate an idea, you test it, and if it doesn’t work, you go back to the drawing board. “We’re not advocating that we should go out there and change clouds,” Neukermans says. “We are advocating that research be done.” He reasons that, even if things go badly, it’s valuable to know what doesn’t work, as it often leads to what might work.