David Keith hopes we don’t have to use his ideas to reverse global warming

Are you sitting down?

Climate scientist David Keith.

webb chappell

Climate scientist David Keith.

IN JUNE, climate scientist David Keith and his neighbors in Calgary, Alberta, were ripping carpets and drywall from their flooded homes — again. In 2005, a “flood of the century” had shattered city records. The 2013 flood was even bigger and forced 100,000 residents to flee to higher ground.

To Keith, the city’s second 100-year flood in less than a decade seemed a little ironic. Calgary is the nerve center of Canada’s oil industry, including tar-sands giant TransCanada, developers of the Keystone XL pipeline, and home to plenty of folks who don’t seem to worry much about climate change. Maybe, Keith mused in an e-mail from the flood zone, this latest example of extreme weather would be “a bit of a reality check.”


Or maybe not. Resistance to global-warming alarms goes well beyond the corporate boardrooms of the oil business. There have been repeated international pledges for deep cuts in carbon dioxide emissions in order to slow the greenhouse effect, in which carbon dioxide gas traps solar radiation in the lower atmosphere. Yet global emissions keep rising. While several developed countries, including the United States, have recently managed to reduce the amount of carbon they pump into the atmosphere — thanks to a major shift from coal to lower-carbon natural gas, an uptick in both efficiency and in renewable energy use, and, last but not least, the global economic slowdown — these cuts have been canceled out by rising emissions from China and other rapidly developing nations. This inertia, and a growing feeling of alarm in the scientific world, has turned Keith into a leading advocate for the real-world testing of sometimes drastic measures that might cool the planet, collectively known as geoengineering.

For decades, geoengineering — which describes various technical proposals, from the seemingly straightforward to ideas that sound like they were dreamed up on Star Trek — was a dirty word among environmental scientists, who wanted less messing with nature, not more. But with carbon dioxide emissions rising and political forces having little global impact, it’s an idea now openly debated at scientific and policy forums. At the same time, it has gone from a side interest of Keith’s to a full-time gig, including writing a book, A Case for Climate Engineering, that comes out next week.

Skeptics think geoengineering is hubristic overreach that is bound to backfire — either by removing the impetus to cut emissions or by causing new problems for the climate, or both. Keith welcomes the debate, but he bristles at being cast as gung-ho. The risks of climate tinkering are real, Keith says. But willful ignorance is riskier. Left unchecked, a warming climate could one day cause enough harm that mounting pressure to do something, anything, to cool the planet quickly would leave few other options. If that day comes, he says, we’d better know what we’re doing.

webb chappell

“Anybody who thinks geoengineering will work perfectly and have no risks is a nutjob,” said David Keith.


ONE EVENING about a month after the Calgary floods, Keith was back in Cambridge attending a geoengineering forum at MIT. He had left a job at an energy policy institute at the University of Calgary in 2011 for Harvard, where he has a joint appointment at the School of Engineering and Applied Sciences and the Kennedy School of Government. The transition to Cambridge from Calgary, where his two kids are finishing high school, has been slow, and Keith has spent the last couple years shuttling between the cities.

That night in Cambridge he was the last of four panelists to arrive, and he bounded up to the front of the room — a lanky 49-year-old sporting black jeans, a cream-colored button-down, and a fresh scruff of beard. As audience members scurried for the last few seats, Keith gobbled a banana, his dinner, and used those few minutes to scroll through his phone.

So it goes lately for Keith, who has become a one-man geoengineering band. In addition to teaching, writing, and attending speaking engagements and far-flung scientific symposiums, he runs a start-up company that plans to build and operate giant “scrubbers” to remove carbon dioxide from the air and then sell the gas to energy companies; they’ll send it deep underground to increase pressure in oil wells and extract hard-to-reach crude, leaving the gas buried, or feed it to algae engineered to make it into biofuel. The scrubbers — which use a chemical reaction similar to one that’s been used in the paper, pulp, and other industries for decades — are among the less risky geoengineering ideas. Many scientists question whether they can cost-effectively help cool the planet, but few fear they’ll do much harm trying. Far more controversial is another idea Keith wants to test — spraying a cloud of tiny particles of sulfuric acid into the stratosphere to reflect the sun’s heat back into space and keep it from warming the Earth. The idea isn’t new, and neither is the strident opposition. Even Keith would love to avoid it. What is new, however, is that many of Keith’s peers are starting to agree that it’s time to take it seriously.

Alli Gold Roberts

Keith participated in a geoengineering forum at MIT in August; he is pictured with Stephen Gardiner, a philosopher at the University of Washington.


BACK IN THE late 1980s, Keith was a doctoral student in experimental physics at MIT, but he began to feel as if his chosen field didn’t deal with any “big real-world problems.” So he hooked up with a group of other graduate students in the Boston area who were all interested in the emerging issue of global warming. The group, from diverse disciplines, was organized by Edward Parson, then a doctoral student at the Kennedy School and now an environmental law professor at UCLA.

“There was a slow-brewing alarm” at those gatherings but no panic, recalls Parson, who has remained a friend and collaborator of Keith’s. “We never imagined that 25 years later we’d still be waiting for the first serious steps to address the issue.”

This was when Keith began to read about geoengineering. Cooling the earth by mimicking volcanoes was first proposed in the mid-1970s by the Soviet climate scientist Mikhail Budyko. A general idea of such a scheme was even included in a report on the environment given to President Lyndon Johnson in 1965. But the risks of a warming planet weren’t really on the national radar at that point. When the issue reemerged in the 1980s, cutting carbon dioxide emissions was the only remedy under consideration.

In 1991, Keith turned down a job offer to do laser physics at Caltech and opted instead for a postdoctoral fellowship in climate policy at Carnegie Mellon University in Pittsburgh. That same year, Mount Pinatubo exploded in the Philippines. The eruption killed hundreds and shot about 20 million tons of sulfur dioxide into the atmosphere. Global temperatures dropped about 1 degree Fahrenheit for two years. In 1992, Keith included stratospheric sulfur among other options in a paper he published that was titled “A Serious Look at Geoengineering.”

“The possibility of unpleasant surprises in the climate system justifies a more coherent (though not large) research program in order to define fallback options needed to make reasonable policy choices,” he wrote.

Nobody outside the climate policy world paid much attention to Keith’s paper. He went on to do other climate-related projects, eventually joining the University of Calgary in 2004, and once again the “fallback options” for cooling the planet collected dust.

In August 2006, another geoengineering article changed everything. It wasn’t so much what it said. What mattered was who said it. The author was Paul Crutzen, a Dutch atmospheric chemist who had won a Nobel Prize. Crutzen wrote that reducing greenhouse gas emissions was “by far the preferred way” to deal with warming. But these efforts had so far been “grossly unsuccessful.”

What Keith had called fallback options Crutzen called an “escape route,” and he, too, lobbied for research. The scheme Crutzen thought had the most promise was the same one that Keith, working with Harvard atmospheric chemist James Anderson, now wants to study — injecting reflective sulfur into the stratosphere.

The two would loft a balloon and release about 1 kilogram of very fine sulfuric acid droplets, then measure the effects of the spray: how the particles disperse or clump together, and the extent to which they trigger ozone-damaging chemical reactions. The amount they would release in their experiment is trivial, says Keith, less than the emissions from a trans-Atlantic airplane flight.

Evidence from computer models, and actual sulfur-spewing volcanoes, suggests that at a much larger scale, spraying these particles into the air could reflect enough sunlight back into space to cool the planet quickly and relatively cheaply. The cooling would be temporary, so the spraying would need to be ongoing, until deep cuts in greenhouse gas emissions could pick up the slack. In this case, the worry isn’t so much that it won’t work, but that it will, with ugly side effects. There are several potential environmental harms from spraying sulfur, including damage to the ozone layer that protects us from ultraviolet radiation.

But because Crutzen was awarded his Nobel for studying ozone depletion, “nobody could claim that he didn’t take ozone destruction seriously,” Keith says.

Suddenly, geoengineering was discussed openly and everywhere. Over the next few years, there were several high-level scientific conferences about whether, when, and how we should try to come to the climate’s rescue. Influential think tanks and scientific academies, including the Bipartisan Policy Center and the British Royal Society, called for research.

Perhaps even more worrisome than the predictable harms, however, is the likelihood that monkeying with the climate could produce unwelcome surprises. What if geotinkering radically alters the monsoons over Southeast Asia or triggers widespread droughts in Africa? What if it suddenly dims the sun over vast stretches of cropland? Who controls the Earth’s thermostat? What if it makes life miserable in a nuclear-armed country that demands we stop spraying or else?

Keith, like other proponents of testing, says we’ll never answer all the “what ifs,” but the only way to deal with many of them is real-world research and international discussions about geoengineering governance — the rules and regulations that would guide future research and possible deployment. Uninformed choices made in a crisis, he says, are usually bad ones.

He picks the year 2020 as a date when world leaders might become so alarmed by the havoc wreaked by global warming that they are ready to push the geoengineering button. Then he works backward, counting the years needed for basic research, developing and testing hardware for delivery and monitoring, attempting larger-scale research, and crafting the necessary international agreements and regulations. “Realistically,” he concludes, “if you want to start doing this in 2020, then we should have started the research a decade ago.”

Critics of this view fear that real-world geoengineering experiments, no matter how small or how well planned, will start us on a slippery slope to full deployment. “Small-scale tests will forever be regarded as inadequate and pressure will come to bear to move swiftly to larger-scale interventions,” concluded a 2009 report by ETC Group, a Canadian nonprofit dedicated to sustainable development and conservation. “This pattern is familiar to people who know the history of genetically modified crops and nuclear weapons.”

Earlier this year, in an effort to allay such fears, Keith coauthored a piece in the journal Science proposing that any small-scale research efforts be accompanied by an international moratorium on large-scale implementation of stratospheric sulfur spraying. “Anybody who thinks geoengineering will work perfectly and have no risks is a nutjob,” says Keith. But, he believes, we need to begin the research now to determine when, if ever, we might consider it worth the risks.

This isn’t a simple cost-benefit analysis for Keith. It’s personal. As an only child growing up in Ottawa, Keith and his dad went on countless canoeing, birding, and hunting outings. After college, he took a year off to explore wilderness areas from the California desert to the high Arctic. He spent four months with scientists studying walruses, the first of many extended wilderness treks. Keith says these experiences awakened a kind of primal attachment to nature, something he doesn’t hesitate to call love.

Climate-change debates focused only on flooded cities, failing crops, and mass extinctions are neglecting that deep-seated motivation for urgent action, says Keith. Even if we live in a wealthy nation and a warming planet poses no immediate threat to our existence, he says, “there’s some value in preserving the natural world simply because we love it and it’s the world we inherited.”

webb chappell

The conspiracy-minded figure that Keith, with his Bill Gates money and his business interests, likely knows the secret geo-clique handshake. They send him tons of e-mail and postcards addressed to “Dr. David ‘Strangelove’ Keith.”


AFTER CRUTZEN’S ARTICLE came out, money started flowing. In 2007, the British billionaire Richard Branson announced the Virgin Earth Challenge — a $25 million prize for the best “commercially viable” way to scrub the atmosphere of greenhouse gases. That same year, Bill Gates set up a climate and geoengineering research fund — a few million dollars a year to support Keith and Ken Caldeira, a climate researcher at the Carnegie Institution for Science who studies ocean acidification and does geoengineering research with computer modeling. In addition, the fund supports other climate and geoengineering projects chosen by Keith and Caldeira. Gates also invested in Keith’s company.

This rush of interest made for strange bedfellows. Calls for geoengineering research were coming from conservation scientists and the Environmental Defense Fund, but also from right-wing policy shops and military consulting firms such as the RAND Corp. In fact, one of geoengineering’s early backers was Edward Teller, father of the hydrogen bomb, and among today’s foremost supporters is Teller’s protege, Lowell Wood, a physicist at the Lawrence Livermore National Laboratory in California.

For some people, the fact that billionaires, military contractors, and doomsday weaponeers are all discussing schemes to control the climate is reason enough to fear and oppose geoengineering. The conspiracy-minded figure that Keith, with his Bill Gates money and his business interests, likely knows the secret geo-clique handshake. They send him tons of e-mail and postcards addressed to “Dr. David ‘Strangelove’ Keith” accusing him of helping the government covertly spray aluminum, barium, magnesium, and other metals in the atmosphere, either for climate control, population control, or mind control. There have been two death threats. During an interview, Keith plays snippets of voice mails he recorded for police.

“You are an evil, evil, evil, evil, evil liar!” a man hisses in one. “Weather geoengineers are the lowest scum ever born!”

Beyond the conspiracy theories, however, is the legitimate fear that some powerful forces would love to find an easy way out of global warming — and those forces include voters who don’t feel like paying more for gas or changing their light bulbs or enduring the economic hits that would surely come with the radical emissions cuts many scientists say are needed. Plus, because carbon dioxide lingers in the atmosphere, it might take a century after those drastic emissions cuts before we felt any of the climate benefits. Asking people to sacrifice now for their great-grandchildren is a hard sell, and many people fear that geoengineering will completely sap the political will to cut emissions.

It’s a fear Keith shares. He mentions it almost every time he writes or speaks about geoengineering, declaring that it should only be a stopgap measure, something we might want to use to hold the ship together while we make the real repairs. Yet, if geoengineering one day becomes a viable option, how it’s used may not be up to sober scientists or even thoughtful policy wonks, notes Simon Nicholson, an American University international relations professor who wrote a chapter on geoengineering for the Worldwatch’s “State of the World 2013” report.

“As soon as this conversation becomes more mainstream, I think you’ll see corporate actors and political actors and individuals who are well-meaning saying, ‘We now have the solution to the world’s problems,’ ” Nicholson says in an interview.

A related critique, by the Australian philosopher and ethicist Clive Hamilton, is that geoengineering springs from the same faith in technology and the same hubris that got us into this mess. It lets people ignore the possibility that “there’s something profoundly wrong in our economic and political system,” Hamilton said on the progressive news show Democracy Now! “because geoengineering comes along and says, ‘Well, look, the system can solve the problem.’ ”

While Keith admits that technology can be “grossly misused,” he doesn’t buy the idea that our drive to develop new tools and technologies is inherently destructive. Usually, he contends, the consequences of human invention are both good and bad. “You’re always inventing new things to fix the last thing,” he says. “Do I think [geoengineering] will create some new problems that we’ll have to fix? Of course.” But he doesn’t think that necessarily justifies doing nothing as the polar icecaps vanish and small island nations sink beneath rising oceans.

“A thing you often get in climate policy is people from the academic world who naively assume you need to know all the answers before you make a decision,” Keith told the audience at the MIT geoengineering forum. “But the reality is, we make a decision by doing it, or by not doing it, every day.

“There’s no getting to certainty here.”

Chris Berdik lives in Dorchester. Send comments to

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