Let’s Just Rejigger the Globe to Cool it Off
Serious scientists are mulling geoengineering — from space sunshades to planetwide aerosols — as reduced-sacrifice methods to address global warming.
In July the American Meteorological Society stepped gingerly into the far outer reaches of the climate debate, a place where a reluctant but growing number of scientists, and even more science fiction fans, have been talking about geoengineering.
The controversial idea suggests that if we can’t curb our greenhouse gas emissions in time to avert cataclysmic climate change, maybe we should contemplate changing the Earth system itself — fertilizing the oceans with iron to stimulate plankton that would sequester carbon dioxide or spraying the stratosphere with dust particles that would deflect sunlight back into space.
Geoengineering poses not just technical and scientific problems, but also any number of ethical ones, not the least of which is a simple question of hubris. We know we can change the climate, because that is inadvertently what man has been doing since the dawn of the industrial revolution. But if that interference has so far been problematic, what makes us think we can now start interfering benevolently? And what right do we have to make that decision for every other species on earth?
Into this debate, the AMS released a policy statement that broached geoengineering without actually endorsing it. Climate policy has until now focused on mitigation (reducing our emissions) and adaptation (preparing for the changes it’s too late to stop). Geoengineering, the AMS says, could come with frightful consequences. But it could also offer a solution of last resort if — and only after — mitigation and adaptation prove to be not enough.
As such, the AMS is now advocating research into geoengineering and a wide-ranging public discussion of its repercussions. That’s markedly different from advocating deployment. But even this much is bound to be divisive.
WHAT ARE WE REALLY
1. Reforestation. This milder idea could also be considered mitigation, which brings up the murky question of exactly how we define geoengineering. Planting trees to sequester carbon dioxide is an old idea, but what if we start mass-planting non-native species, or planting trees where trees didn’t used to be?
2. Ocean fertilization. In this potentially less dramatic (and effective?) idea, we could dump iron, nitrates and phosphorous into the oceans to stimulate the growth of algae that would pull carbon dioxide out of the atmosphere and deep underwater. Small-scale experiments have led to mixed results.
3. Cloud whitening. Just as scientists have advocated painting our roofs and roads white to deflect more sunlight, could we do the same thing with clouds? Granted, they’re already pretty white, but some scientists suggest we could make them more reflective by spraying them with droplets of seawater.
4. Stratospheric aerosols. When Mt. Pinatubo erupted in 1991, 20 million tons of sulfur dioxide were spewed into the atmosphere, cooling the earth by about 1 degree Fahrenheit the following year. Could we achieve the same effect by using airplanes or balloons to inject sulfate aerosols into the stratosphere?
5. Mirrors in space. This proposal would suspend a Greenland-sized mirror, or millions of smaller ones, in between the earth and sun, held in orbit by gravitational pull. Getting them up there would be astronomically expensive, but one cost-cutting measure suggests saving transportation time and money by manufacturing the mirrors on the moon. Really.
You May Say I’m a Dreamer
The AMS is one of several serious-minded bodies that have begun discussing the idea the last three years. Nobel Prize-winning atmospheric chemist Paul Crutzen shocked his peers in 2006 with an essay in the journal Climactic Change suggesting man try to mimic the success major volcanic eruptions have had in temporarily cooling the planet.
In 2006 NASA held a workshop on the topic. The following year, a seminal two-day summit was convened at Harvard on geoengineering. The National Academy of Sciences held a workshop this June, which was followed in July by a series of presentations in Britain by the Royal Society of Chemistry and Royal Academy of Engineering.
The Royal Society, the British national academy of science, then followed this month with a dire report predicting that we’ll have no other hope than to rely on the sketchy science of geoengineering in the long run if we don’t start mitigating much more seriously today. At that point, geoengineering and its many potentially dangerous consequences will become “the price we may have to pay” for failure to act for so long, the chair of the study warned in publishing it.
Almost universally, the scientists involved bring a heavy heart.
“We all wished that we didn’t have to do this,” said Michael MacCracken, chief scientist for climate change programs at the Climate Institute. But the sense is growing that global warming is changing the world faster than the Intergovernmental Panel on Climate Change can put out status reports. And, at the same time, diplomatic efforts to get worldwide mitigation underway — already two decades behind schedule — continue to stall.
Geoengineering could attempt to reverse global warming through two strategies: either by blocking some of the incoming heat from the sun, or by capturing warming gases like carbon dioxide. It is the first strategy, tied to such radical and expensive proposals as suspending millions of mirrors, or a massive sunshade, in space, that poses the greatest questions of ethics and global governance.
“The challenge we’re sort of looking toward is figuring out how do you even do the research to try and become convinced this would work,” said MacCracken, who worked on the AMS statement. “Before you get the public confidence up, you have to make sure you get the scientific confidence up.”
Among geoengineering’s many problems is its dubious history. Man has been trying to geoengineer the climate for years, although until now the goal has more often been to massage an ideal climate — to bring rain to the Great Plains, for instance — and not to restore the climate to what it once was. Geoengineering’s forefathers were not Nobel laureates but out-there dreamers (and often not even scientists). Would-be 19th-century American rainmakers thought they could bombard the sky into storming with artillery.
Geoengineering also has a long history of attempted military application, an effort that peaked during the Vietnam War when the American military seeded clouds it hoped would then pour on Viet Cong supply routes and resources. That episode prompted — at the Soviet Union’s urging – creation of the U.N. Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques (better known as ENMOD).
“If, as history shows, fantasies of weather and climate control have chiefly served commercial and military interests,” he wrote, “why should we expect the future to be different?”
In its more recent reincarnation, most of today’s discussion of genoengineering has been held behind closed doors, notes Samuel Thernstrom, co-director of the American Enterprise Institute’s Geoengineering Project. It’s a sign, he said, that scientists have feared taking the topic public. One objection to geoengineering is that it could have unknown consequences — “Donald Rumsfeld was right about one thing: There are unknown unknowns,” said Alan Robock, a professor in the department of environmental sciences at Rutgers.
The unintended consequences, though, are an argument against deployment, not research. Another argument opposes even that much: the idea that simply by putting geoengineering on the table, we may remove the sense of urgency for the world to mitigate.
“If that’s the case, [geoengineering] is clearly a disaster in my opinion,” said Paul Higgins, an AMS policy fellow who was the chair of the drafting committee. Because of this fear, the AMS statement went to great pains to stress that geoengineering — if it is attempted — must be done in conjunction with aggressive mitigation, not as a substitute for it.
MacCracken and Thernstrom suggest the opposite effect may come to pass — that geoengineering, as Thernstrom put it, may be the key that makes mitigation work.
“Sometimes,” MacCracken said, “just indicating the magnitude of what we’re doing to the global climate by indicating the magnitude of what you have to do to counter it helps people understand they have to do something.”
Who Calls the Shots?
Robock, who also contributed to the AMS statement, outlined a laundry list of other concerns in a 2006 issue of the Bulletin of Atomic Scientists. Who would ultimately wind up with the technology to alter the climate? What if it lands in the hands of a private corporation that values profits over the public good? What if a lone, wealthy citizen deploys geoengineering without the consent of the world? And what if by blocking out some of the sun, we reduce our ability to create solar power?
“The question is: If there is an emergency, do we have a Plan B in our back pocket to solve it?” Robock said. “Right now, I don’t know if there’s anything in our pocket or not.”
But that raises another question: How will we know when we’re in an emergency?
“There’s no global governance mechanism to do that,” Robock said. “There’s winners and losers, so how do you decide when it’s gotten out of hand?”
Robock is also concerned about geoengineering’s image problem. If the U.S. leads the way with any kind of military involvement — the enigmatic Defense Advanced Research Projects Agency is another group that has recently begun discussing geoengineering — the world won’t trust American intentions. Geoengineering has also drawn some unlikely bedfellows in climate scientists and conservative-leaning think tanks like AEI.
Geoengineering may be a tempting idea for conservatives who have traditionally opposed mandatory emissions reduction and for industries that have a lot of money invested in the fossil fuel economy.
For his part, Thernstrom says AEI has never engaged in climate change denialism; rather, it has done the work of economists trying to figure out how to reduce emissions in the most cost-effective way. Geoengineering, he believes, may buy us time to transition out of the carbon economy in a way that’s economically and politically feasible.
“I do understand still there is this larger perception that conservatives are opposed to climate action, and do we really want them coming in on geoengineering when it fits into this moral hazard fear?” Thernstrom said. “My argument is, people who believe geoengineering is an important idea, who believe we should be researching it, talking about it — they should be welcoming whatever support they can get, wherever they can get it.”
Geoengineering also turns on its head the entrenched environmentalist idea that the most effective solution involves the greatest personal sacrifice: that we must give up our cars, our washing machines and our single-use plastic grocery bags. The idea that we could partly address climate change without painful or expensive individual sacrifice appeals to conservatives, but Thernstrom said it also speaks to what polls tell us about most Americans. They care about climate change, but they’re not prepared to give up much to address it.
This idea, he thinks, may also make selling geoengineering overseas easier than achieving consensus for a mitigation regime like the largely ineffective Kyoto Treaty. We don’t have to ask Brazil to spend any money or China and India to give up industrialization; we just have to get them to assent to the idea of geoengineering.
That prospect does sound easier until you consider that we don’t need a scientific consensus; we need a philosophical one. And getting the world’s many cultures — as opposed to economies — to agree on an idea so fundamentally discomforting may be just as hard.
“If you really do go to geoengineering, essentially the impression is going to be that there’s no further acts of God with respect to natural events,” MacCracken said. “It’s something you have to approach I think very cautiously.”
If we do go there, could we figure out which schemes are reversible, start with those and hope we can get the climate under control before we have to commit to geoengineering indefinitely?
That would be the best-case scenario, according to Higgins, in a world in which we have to geoengineer. In an even better world, he said, all of this talk is about a strategy that, once we’ve debated it at great length, made peace with its difficult questions and invested seriously in its research, we won’t actually have to do.
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