This Scientist Has a Risky Plan to Cool Earth. There’s Growing Interest (David Keith wants to spray a pollutant into the sky to block some sunlight. He says the benefits would outweigh the danger)—The New York Times
Geoengineering News
Shuchi Talati, the founder of a nonprofit organization called the Alliance for Just Deliberation on Solar Geoengineering, called the technology “a double-edged sword.”
“It could be a way to limit human suffering,” she said. “At the same time, I think it can also exacerbate suffering if used in a bad way.”
In a series of interviews, Dr. Keith, a professor in the University of Chicago’s department of geophysical sciences, countered that the risks posed by solar geoengineering are well understood, not as severe as portrayed by critics and dwarfed by the potential benefits.
If the technique slowed the warming of the planet by even just one degree Celsius, or 1.8 degrees Fahrenheit, over the next century, Dr. Keith said, it could help prevent millions of heat-related deaths each decade.
A planet transformed by solar geoengineering would not be noticeably dimmer during the daytime, according to his calculations. But it could produce a different kind of twilight, one with an orange hue.
He agrees that nations should stop burning coal, oil and gas, period. But Dr. Keith believes in going further.
Lean and athletic at 60, with glacier-blue eyes, Dr. Keith has spent his life outside the lab rock climbing, sea kayaking and skiing in the Arctic. He is deeply troubled by the myriad ways climate change is disrupting the natural world.
By lowering global temperatures, solar geoengineering could help restore the planet to its preindustrial state, recreating conditions that existed before enormous amounts of carbon dioxide were pumped into the atmosphere and began to cook the Earth, he said.
If there were a global referendum tomorrow on whether to begin solar geoengineering, he said he would vote in favor.
“There certainly are risks, and there certainly are uncertainties,” he said. “But there’s really a lot of evidence that the risks are quantitatively small compared to the benefits, and the uncertainties just aren’t that big.”
The only thing more dangerous than his solution, he suggested, may be not using it at all.
To understand just how contentious Dr. Keith’s work can be, consider what happened when he tried to perform an initial test in preparation for a solar geoengineering experiment known as Scopex.
Then a professor at Harvard, Dr. Keith wanted to release a few pounds of mineral dust at an altitude of roughly 20 kilometers and track how the dust behaved as it floated across the sky.
A test was planned in 2018, possibly over Arizona, but Dr. Keith couldn’t find a partner to launch a high-altitude balloon. When details of that plan became public, a group of Indigenous people objected and issued a manifesto against geoengineering.
Three years later, Harvard hired the Swedish space corporation to launch a balloon that would carry the equipment for the test. But before it took place, local groups once again rose up in protest.
The Saami Council, an organization representing Indigenous peoples, said it viewed solar geoengineering “to be the direct opposite of the respect we as Indigenous Peoples are taught to treat nature with.”
Greta Thunberg, the Swedish climate activist, joined the chorus. “Nature is doing everything it can,” she said. “It’s screaming at us to back off, to stop — and we are doing the exact opposite.”
Within months, the experiment was called off.
“A lesson I’ve learned from this is that if we do this again, we won’t be open in the same way,” Dr. Keith said.
Behind the scenes, the Harvard team and its advisory committee became mired in finger pointing over who was to blame for the collapse of the project. Dr. Talati, a member of the Scopex advisory board, said it was “the moment of peak chaos.”
It didn’t help that there were personality conflicts. Several committee members said Dr. Keith could be ornery and headstrong, correcting colleagues in casual conversation and belittling those with whom he disagreed.
“I can be abrasive and difficult,” Dr. Keith acknowledged. “I am sometimes inappropriately forceful in making my point. I’m intense.”
Opponents of solar geoengineering cite several main risks.
They say it could create a “moral hazard,” mistakenly giving people the impression that it is not necessary to rapidly reduce fossil fuel emissions.
“The fundamental problem is that we think we’re so smart that we don’t have to pay attention to nature’s boundaries,” Dr. Suzuki said. “But we haven’t dealt with the root cause of the problem, which is us.”
The second main concern has to do with unintended consequences.
“This is a really dangerous path to go down,” said Beatrice Rindevall, the chairwoman of the Swedish Society for Nature Conservation, which opposed the experiment. “It could shock the climate system, could alter hydrological cycles and could exacerbate extreme weather and climate instability.”
And once solar geoengineering began to cool the planet, stopping the effort abruptly could result in a sudden rise in temperatures, a phenomenon known as “termination shock.” The planet could experience “potentially massive temperature rise in an unprepared world over a matter of five to 10 years, hitting the Earth’s climate with something that it probably hasn’t seen since the dinosaur-killing impactor,” Dr. Pierrehumbert said.
On top of all this, there are fears about rogue actors using solar geoengineering and concerns that the technology could be weaponized. Not to mention the fact that sulfur dioxide can harm human health.
Dr. Keith is adamant that those fears are overblown. And while there would be some additional air pollution, he claims the risk is negligible compared to the benefits.
“There’s plenty of uncertainty about climate responses,” he said. “But it’s pretty hard to imagine if you do a limited amount of hemispherically balanced solar geo that you don’t reduce temperatures everywhere.”
Last year, after the failure to launch the Scopex experiment in Sweden, Dr. Keith made a move that stunned his colleagues. He announced he was closing the door on 13 years at Harvard and taking his ambitions to the University of Chicago, where he would build a new program around climate interventions, including solar geoengineering.
“I don’t know whether that stuff will ever get used,” said Mr. Gates, a major investor in climate technology. “I do believe that doing the research and understanding it makes sense.”
Dr. Keith’s career can be traced to his father, Tony Keith, a wildlife biologist who attended the first global gathering to address threats to nature, the 1972 United Nations Conference on the Human Environment in Stockholm.
Dyslexia prevented him from learning to read until late in 4th grade, but when he was finally able to make sense of written words, he became a voracious reader. He also loved camping and, at 17, hiked a stretch of the Appalachian Trail solo.
After graduating from the University of Toronto, he spent months rock climbing. Looking for a way to get paid to live in the wilderness, he got a job studying walruses in the Canadian Arctic.
Dr. Keith eventually enrolled in a doctoral program at the Massachusetts Institute of Technology to study experimental physics.
In 1992, he published an academic paper, “A Serious Look at Geoengineering,” that raised the questions that would shape his career: Who should authorize the use of these technologies? Who is liable if something goes wrong?
His academic career took him from Carnegie Mellon University to the University of Calgary, where he began investigating ways to capture and store carbon dioxide. The next stop was Harvard, where he got serious about solar geoengineering.
In 2006, a mutual acquaintance introduced him to Mr. Gates, who wanted to learn more about technologies that might help fight global warming. The two men discussed climate and technology in a series of meetings over the next 10 years.
Then in 2009, Dr. Keith founded Carbon Engineering, a company that developed a process for pulling carbon dioxide from the atmosphere. Investors included Mr. Gates, Chevron and N. Murray Edwards, who made billions pumping oil from the Canadian oil sands.
Last year Carbon Engineering was acquired by Occidental Petroleum, a major oil and gas producer based in Texas, for $1.1 billion. Dr. Keith owned about 4 percent of the company at the time of the sale, delivering him a personal windfall of about $72 million.
Occidental is now building a series of enormous carbon capture plants. It plans to sell carbon credits to big companies like Amazon and AT&T that want to offset their emissions. Critics say that will only delay the phaseout of fossil fuels while allowing an oil company to profit.
“Of course I’m uncomfortable about it being sold to an oil company, no question,” Dr. Keith said, adding that he plans to give away most of his profits from the sale of Carbon Engineering, perhaps to a conservation group.
On a summer Monday in Cambridge, Mass., the Harvard campus was mostly quiet. But inside one classroom, a standing-room-only crowd listened as experts discussed the merits and risks of solar geoengineering.
Among those featured was Frank Keutsch, Dr. Keith’s former collaborator on the Scopex experiment.
Dr. Keutsch is less sanguine than Dr. Keith when considering its potential risks.
