Which is how it comes to pass that, more than ten years later, Caldeira, Wood, and Myhrvold—the onetime peacenik, the onetime weapons architect, and the onetime Viking fanboy—are huddled together in a former Harley-Davidson repair shop showing off their scheme to stop global warming.
It wasn’t just the cooling potential of stratospheric sulfur dioxide that surprised Caldeira. It was how little was needed to do the job: about thirty-four gallons per minute, not much more than the amount of water that comes out of a heavy-duty garden hose.
Warming is largely a polar phenomenon, which means that high-latitude areas are four times more sensitive to climate change than the equator. By IV’s estimations, 100,000 tons of sulfur dioxide per year would effectively reverse warming in the high Arctic and reduce it in much of the Northern Hemisphere.
That may sound like a lot but, relatively speaking, it is a smidge. At least 200 million tons of sulfur dioxide already go into the atmosphere each year, roughly 25 percent from volcanoes, 25 percent from human sources like motor vehicles and coal-fired power plants, and the rest from other natural sources like sea spray.
So all that would be needed to produce a globe-changing effect is one-twentieth of 1 percent of current sulfur emissions, simply relocated to a higher point in the sky. How can this be? Myhrvold’s answer: “Leverage!”
Leverage is the secret ingredient that distinguishes physics from, say, chemistry. Think back to the Salter Sink, IV’s device for preventing hurricanes. Hurricanes are destructive because they gather up the thermal energy in the ocean’s surface and convert it into physical force, a primordial act of leverage creation. The Salter Sink ruptures that process by using wave power to continually sink the warm water all through hurricane season.
“A kilogram of sulfur dioxide, emitted by a truck or a bus or a power plant into the troposphere, does much less good for you than in the stratosphere,” Myhrvold says. “So you get a huge leverage, and that’s a pretty cool thing. That’s why Archimedes said, ‘If you give me a fulcrum, I can move the world.’”*
So once you eliminate the moralism and the angst, the task of reversing global warming boils down to a straightforward engineering problem: how to get thirty-four gallons per minute of sulfur dioxide into the stratosphere?
The answer: a very long hose.
That’s what IV calls this project—a “garden hose to the sky.” Or, when they’re feeling slightly more technical, a “stratospheric shield for climate stabilization.” Considering its scientific forebear and the way it wraps the planet in a protective layer, perhaps it should be called Budyko’s Blanket.
For anyone who loves cheap and simple solutions, things don’t get much better. Here’s how it works. At a base station, sulfur would be burned into sulfur dioxide and then liquefied. “The technology for doing this is well known,” says Wood, “because early in the twentieth century, sulfur dioxide was the major refrigerant gas.”
The hose, stretching from the base station into the stratosphere, would be about eighteen miles long but extremely light. “The diameter is just a couple inches, not some giant-ass pipe,” says Myhrvold. “It’s literally a specialized fire hose.”
The hose would be suspended from a series of high-strength, helium-filled balloons fastened to the hose at 100-to 300-yard intervals (a “string of pearls,” IV calls it), ranging in diameter from 25 feet near the ground to 100 feet near the top.
The liquefied sulfur dioxide would be sent skyward by a series of pumps, affixed to the hose at every 100 yards. These too would be relatively light, about forty-five pounds each—“smaller than the pumps in my swimming pool,” Myhrvold says. There are several advantages to using many small pumps rather than one monster pump at the base station: a big ground pump would create more pressure, which, in turn, would require a far heavier hose; even if a few of the small pumps failed, the mission itself wouldn’t; and using small, standardized units would keep costs down.
At the end of the hose, a cluster of nozzles would spritz the stratosphere with a fine mist of colorless liquid sulfur dioxide.
Thanks to stratospheric winds that typically reach one hundred miles per hour, the spritz would wrap around the earth in roughly ten days’ time. That’s how long it would take to create Budyko’s Blanket. Because stratospheric air naturally spirals toward the poles, and because the arctic regions are more vulnerable to global warming, it makes sense to spray the sulfur aerosol at high latitude—with perhaps one hose in the Southern Hemisphere and another in the Northern.
Myhrvold, in his recent travels, happened upon one potentially perfect site. Along with Bill Gates and Warren Buffett, he was taking a whirlwind educational tour of various energy producers—a nuclear plant, a wind farm, and so on. One of their destinations was the Athabasca Oil Sands in northern Alberta, Canada.
Billions of barrels of petroleum can be found there, but it is heavy, mucky crude. Rather than lying in a liquid pool beneath the earth’s crust, it is mixed in, like molasses, with the surface dirt. In Athabasca you don’t drill for oil; you mine it, scooping up gigantic shovels of earth and then separating the oil from its waste components.
One of the most plentiful waste components is sulfur, which commands such a low price that oil companies simply stockpile it. “There were big yellow mountains of it, like a hundred meters high by a thousand meters wide!” says Myhrvold. “And they stair-step them, like a Mexican pyramid. So you could put one little pumping facility up there, and with one corner of one of those sulfur mountains, you could solve the whole global warming problem for the Northern Hemisphere.”
It is interesting to think what might have happened if Myhrvold was around one hundred years ago, when New York and other cities were choking on horse manure. One wonders if, while everyone else looked at the mountains of dung and saw calamity, he might have seen opportunity.
On balance, Budyko’s Blanket is a fiendishly simple plan. Considering the complexity of climate in general and how much we don’t know, it probably makes sense to start small. With the fire-hose approach, you could begin with a trickle of sulfur and monitor the results. The amount could be easily dialed up or down—or, if need be, turned off. There is nothing permanent or irreversible about the process.
And it would be startlingly cheap. IV estimates the “Save the Arctic” plan could be set up in just two years at a cost of roughly $20 million, with an annual operating cost of about $10 million. If cooling the poles alone proved insufficient, IV has drawn up a “Save the Planet” version, with five worldwide base stations instead of two, and three hoses at each site. This would put about three to five times the amount of sulfur dioxide into the stratosphere. Even so, that would still represent less than 1 percent of current worldwide sulfur emissions. IV estimates this plan could be up and running in about three years, with a startup cost of $150 million and annual operating costs of $100 million.
So Budyko’s Blanket could effectively reverse global warming at a total cost of $250 million. Compared with the $1.2 trillion that Nicholas Stern proposes spending each year to attack the problem, IV’s idea is, well, practically free. It would cost $50 million less to stop global warming than what Al Gore’s foundation is paying just to increase public awareness about global warming.
And there lies the key to the question we asked at the beginning of this chapter: What do Al Gore and Mount Pinatubo have in common? The answer is that Gore and Pinatubo both suggest a way to cool the planet, albeit with methods whose cost-effectiveness are a universe apart.
This is not to dismiss the potential objections to Budyko’s Blanket, which are legion. First of all, would it work?
The scientific evidence says yes. It is basically a controlled mimicry of Mount Pinatubo’s eruption, whose cooling effects were exhaustively studied and remain unchallenged.
Perhaps the stoutest scientific argument in favor of the plan came from Paul Crutzen, a Dutch atmospheric scientist whose environmentalist bona fides run even deeper than Caldeira’s. Crutzen won a N
obel Prize in 1995 for his research on atmospheric ozone depletion. And yet in 2006, he wrote an essay in the journal Climatic Change lamenting the “grossly unsuccessful” efforts to emit fewer greenhouse gases and acknowledging that an injection of sulfur in the stratosphere “is the only option available to rapidly reduce temperature rises and counteract other climatic effects.”
Crutzen’s embrace of geoengineering was considered such a heresy within the climate-science community that some peers tried to stop publication of his essay. How could the man reverently known as “Dr. Ozone” possibly endorse such a scheme? Wouldn’t the environmental damage outweigh the benefits?
Actually, no. Crutzen concluded that damage to the ozone would be minimal. The sulfur dioxide would eventually settle out in the polar regions but in such relatively small amounts that there, too, significant harm was unlikely. If a problem did arise, Crutzen wrote, the sulfur injection “could be stopped on short notice…which would allow the atmosphere to return to its prior state within a few years.”
Another fundamental objection to geoengineering is that it intentionally alters the earth’s natural state. To that, Myhrvold has a simple answer: “We’ve already geoengineered the earth.”
In just a few centuries, we will have burned up most of the fossil fuel that took 300 million years of biological accumulation to make. Compared with that, injecting a bit of sulfur into the sky seems pretty mild. As Lowell Wood points out, sulfur isn’t even the optimal chemical for a stratospheric shield. Other, less noxious-sounding materials—aluminized plastic micro beads, for instance—could make an even more efficient sunscreen. But sulfur is the most palatable choice “simply because we’ve got the volcano proof of feasibility,” Wood says, “and along with that, a proof of harmlessness.”
Wood and Myhrvold do worry that Budyko’s Blanket might create an “excuse to pollute.” That is, rather than buying time for us to create new energy solutions, it would lure people into complacency. But blaming geoengineering for this, Myhrvold says, is like blaming a heart surgeon for saving the life of someone who fails to exercise and eats too many french fries.
Perhaps the single best objection to the garden hose idea is that it is too simple and too cheap. As of this writing, there is no regulatory framework to prohibit anyone—a government, a private institution, even an individual—from putting sulfur dioxide in the atmosphere. (If there were, many of the world’s nearly eight thousand coal-burning electricity units would be in a lot of trouble.) Still, Myhrvold admits that “it would freak people out” if someone unilaterally built the thing. But of course this depends on the individual. If it were Al Gore, he might snag a second Nobel Peace Prize. If it were Hugo Chávez, he’d probably get a prompt visit from some U.S. fighter jets.
One can also imagine the wars that might break out over who controls the dials on Budyko’s Blanket. A government that depends on high oil prices might like to crank up the sulfur to keep things extra cool; others, meanwhile, might be happier with longer growing seasons.
Lowell Wood recounts a lecture he once gave, during which he mentioned that a stratospheric shield could also filter out damaging ultraviolet rays. An audience member suggested that fewer ultraviolet rays would lead to more people getting rickets.
“My response,” Wood says, “was that your pharmacist can take care of that with vitamin D, and it’ll be better for your overall health as well.”
All the rocket scientists, climate scientists, physicists, and engineers around the IV conference table chuckle at Wood’s riposte. Then someone asks if IV, with Budyko’s Blanket up its sleeve, should be working toward a rickets-prevention patent. Now they laugh louder.
But it’s not entirely a joke. Unlike most of the patents IV owns, Budyko’s Blanket has no clear route to profits. “If you were an investor of mine,” Myhrvold says, “you might ask: ‘Remind me again why you’re working on this?’” Indeed, many of IV’s most time-consuming projects, including a variety of AIDS and malaria solutions, are substantially pro bono work.
“This is the world’s greatest philanthropist sitting on the other side of the table,” Wood says with a chuckle and a nod toward Myhrvold. “Involuntarily so, but there he is.”
As dismissive as Myhrvold can be toward the prevailing sentiments on global warming, he is quick to deny that he dismisses global warming itself. (If that were the case, he’d hardly spend so much of his company’s resources working on solutions.) Nor is he arguing for an immediate deployment of Budyko’s Blanket—but, rather, that technologies like it be researched and tested so they are ready to use if the worst climate predictions were to come true.
“It’s a bit like having fire sprinklers in a building,” he says. “On the one hand, you should make every effort not to have a fire. But you also need something to fall back on in case the fire occurs anyway.” Just as important, he says, “it gives you breathing room to move to carbon-free energy sources.”
He is also eager to get geoengineering moving forward because of what he sees as “a real head of steam” that global-warming activists have gathered in recent years.
“They are seriously proposing doing a set of things that could have enormous impact—and we think probably negative impact—on human life,” he says. “They want to divert a huge amount of economic value toward immediate and precipitous anti-carbon initiatives, without thinking things through. This will have a huge drag on the world economy. There are billions of poor people who will be greatly delayed, if not entirely precluded, from attaining a First World standard of living. In this country, we can pretty much afford the luxury of doing whatever we want on the energy-and-environment front, but other parts of the world would seriously suffer.”
Certain new ideas, no matter how useful, are invariably seen as repugnant. As we mentioned earlier, a market for human organs—even though it might save tens of thousands of lives each year—is one such example.
Over time, some ideas do cross the repugnance barrier to become reality. Charging interest on loans. Selling human sperm and eggs. Profiting from a loved one’s premature death. This last example of course describes how life insurance works. Today it is standard practice to wager on your own death in order to provide for your family. Until the mid-nineteenth century, life insurance was considered “a profanation,” as the sociologist Viviana Zelizer writes, “which transformed the sacred event of death into a vulgar commodity.”
Budyko’s Blanket may simply be too repugnant a scheme to ever be given a chance. Intentional pollution? Futzing with the stratosphere? Putting the planet’s weather in the hands of a few arrogant souls from Seattle? It is one thing for climate heavyweights like Paul Crutzen and Ken Caldeira to endorse such a solution. But they are mere scientists. The real heavyweights in this fight are people like Al Gore.
And what does he think of geoengineering?
“In a word,” Gore says, “I think it’s nuts.”
If the garden-hose-to-the-sky idea doesn’t fly, IV has another proposal that relies on the same science but is perhaps slightly less repugnant. As it turns out, the amount of stratospheric sulfur necessary to cool the planet is equal to the amount that just a handful of coal-burning power plants already belch out. This second plan calls for simply extending the smokestacks at a few strategically located plants. So instead of spewing their sulfur-laden smoke several hundred feet into the air, these smokestacks would release it some eighteen miles high, into the stratosphere, where it would have the same net cooling effect as the garden-hose scheme.
This plan is appealing because it simply repurposes existing pollution without adding any more. Although an eighteen-mile-high smokestack might sound like a hard thing to build, IV has figured out how—essentially by attaching a long, skinny hot-air balloon to an existing power-plant smokestack, creating a channel that lets the hot sulfur gases rise by their own buoyancy into the stratosphere. This project is dubbed, naturally, “chimney to the sky.”
And if even that plan is too repugnant, IV has some
thing entirely different, a plan that is practically heavenly: a sky full of puffy white clouds.
This is the brainchild of John Latham, a British climate scientist who recently joined the IV stable of inventors. Latham is a gentle, soft-spoken man in his late sixties who is also a rather serious poet. So it caught his ear when, long ago, he stood on a mountaintop in North Wales with his eight-year-old son Mike, gazing down at a sunset, and the boy, pointing out how shiny the clouds were, called them “soggy mirrors.”
Precisely!
“On balance, the role of clouds is to produce a cooling,” says Latham. “If clouds didn’t exist in the atmosphere, the earth would be a lot hotter than it is now.”
Even man-made clouds—the contrails from a jet plane, for instance—have a cooling effect. After the September 11 terrorist attacks, all commercial flights in the United States were grounded for three days. Using data from more than four thousand weather stations across the country, scientists found that the sudden absence of contrails accounted for a subsequent rise in ground temperature of nearly 2 degrees Fahrenheit, or 1.1 degrees Celsius.
There are at least three essential ingredients for the formation of clouds: ascending air, water vapor, and solid particles known as cloud condensation nuclei. When planes fly, particles in the exhaust plume serve as the nuclei. Over landmasses, dust particles do the job. But there are far fewer cloud-friendly nuclei over the world’s oceans, Latham explains, so the clouds contain fewer droplets and are therefore less reflective. As a result, more sunlight reaches the earth’s surface. The ocean, because it is dark, is particularly good at absorbing the sun’s heat.
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