May 8th, 2015


Climate Scientist, Carnegie Institution for Science, Department of Global Ecology at Stanford University

Professor of Law, UC Davis

Co-chair, Task Force on Geoengineering, Bipartisan Policy Center

Physicist and Inventor


Imagine Superman flying through the clouds, spraying a mist that reflects the sun’s rays and cools the earth.  Sounds like science fiction – but scientists are indeed studying this and other ways to alter the atmosphere and fight global warming.  Whether you call it geoengineering, comic book fantasy or “hacking the sky,” the idea is getting serious consideration.

Stanford geoengineering expert Ken Caldeira first heard the concept broached during a climate summit in 1998, by astrophysicist Lowell Wood. “His idea was to offset the effects of increased greenhouse gas concentrations by reflecting some of the sun's warming rays back to space,” Caldeira remembers.  “And I thought that this would make no sense and wouldn’t work…And we came back and did some computer model simulations using climate models. It turned out, much to our surprise, that it worked quite well!”

Jane Long co-chairs the Task Force on Geoengineering at the Bipartisan Policy Center. She explains that the panel was formed at the request of the US government, “because they wanted to hear from scientists about whether or not this was a good idea…and lo and behold, it wasn't just scientists actually. We had people that were diplomats.  We had political scientists.  We had ethicists on this panel.” The unanimous conclusion, she reports, was “that we needed to start looking into this technology.”

Physicist Armand Neukermans is part of a team that has been exploring what he calls “marine cloud brightening,” based on an idea by atmospheric scientist John Latham.

Adding water droplets to clouds makes them brighter, Neukermans explains, enabling them to reflect more light. “The idea is that if you would help by a natural means to bring more droplets in there, nuclei as they call it, they will become droplets too. The clouds will lighten…this is a relatively simple idea that basically uses the clouds like a mirror.”

It sounds clever enough. But even if it does work, could there be unexpected complications?  What are the technical, moral and political implications of tinkering with Mother Nature?

Albert Lin, professor of law at UC Davis, says the idea is definitely controversial “because it's talking about potentially trying to affect, influence the climate at this very broad scale, akin to perhaps you could say playing God. And the question is, of course, who would do this?”

The question of who would control the technology – and be responsible for its consequences – should be made by the international community as a whole, says Lin.  But the controversial aspect may be one reason that spray-painting the sky remains in the experimental stage.  Are researchers waiting for a “social license” in order to move ahead?

According to Long, it all comes down to funding. “I think there's quite a few people who are ready to do small scale, very low risk experiments that are looking at actually how the chemistry and the physics actually occurs,” she says.  “They're ready to go, but there's no money.  It's the government that is holding back on the social license.”  

Private funding could save the day -- Bill Gates has reportedly expressed interest in putting money towards the geoengineering of climate solutions.  But, Long cautions, it’s important to keep such research in the public eye.

“Because as we move from very, very small-scale research with literally no physical risks associated with it,” to larger-scale operations, “say over 1,000 kilometers or something like that, 1000 miles -- you wouldn't want that kind of research to be done unless it was publicly available, publicly governed and was totally transparent to the public about what was being done and why it was being done.”

Some see a risk that this technology, like nuclear power, could be turned against us if it falls into the wrong hands. “There are some parallels with nuclear technology,” Lin agrees. “You could see some of the technology that's being developed here potentially being used in a military way, or at least in a way to disadvantage one's neighbors whom one disagrees with.”

And while the potential hazards to our atmosphere might give pause to some, others might argue that our very presence on earth is already affecting the planet. “We all changed the climate a little bit today in our activities, but we did it unintentionally,” says Long.  

“But the fact is that we are entering a time in the earth's history where we can't avoid that intentionality.  We know now that we're changing the climate. And so the idea of thinking about this…may bring us to a place where we actually do a better job of that intention, of managing this planet.”

“I think there's often an assumption that deployment of these technologies will be widely unpopular,” says Caldeira. “But if you're in Phoenix and it's getting to be 120 degrees and there is no rain, and somebody spraying some seawater off of Los Angeles can make you have cooler weather and moister weather,” there’s many who would welcome it.

“We don't really know how bad climate change will get,” Caldeira continues. “But if it really does turn out to be catastrophic, there could be real demand to do something quickly.”

On the question of morality, Long is adamant. “I think it's immoral not to do it,” she asserts. “I think we have to take responsibility for the earth, because that's where we all live and because that's where our children and their children are going to live.  And so the need to learn how to take responsibility is paramount in our survival.

“Are we doomed?  We're not doomed -- if we take responsibility.”


Related Links:

National Academy of Sciences Report: Climate Intervention: Reflecting Sunlight to Cool Earth

Bipartison Policy Center Task Force on Geoengineering

Policy Report: Start research on climate engineering

SF Gate: Looking to Sky to Fight Climate Change


- Anny Celsi
April 28, 2015
The Commonwealth Club of California
Photos by Ed Ritger