As global warming advances, risky responses gain a following

A new paper proposes using large balloons to scatter sunlight and slow global warming.

A British chemical engineer, Peter Davidson, presented a webinar early this morning on his strategy to combat global warming: Fog Earth’s upper atmosphere with paint particles, streamed from giant balloons, to reflect sunlight away from Earth and offset the greenhouse effects of burning fossil fuel.

Peter DavidsonPeter Davidson

Plan B, indeed.

As the years roll by with essentially no meaningful progress on cutting carbon emissions, “geo-engineering” solutions like Davidson’s attract more attention and perhaps even faith from those inclined to believe that since technology got us into this mess, technology can somehow get us out. (A piece on Davidson’s idea in The Chemical Engineer  has drawn favorable references in places as diverse as Gasworld  and Earth Times.)

And the idea of mirroring sunlight away from Earth is not, at a certain conceptual level, completely insane. But in practice it might be close.

Making like Pinatubo

Like others before him, Davidson argues for manmade mimicry of a famous natural interruption in the planet’s warming trend — the 1991 eruption of Mount Pinatubo in the Philippines, which pumped 20 million metric tons of sulfur dioxide into the stratosphere, creating a mirroring blanket of sulfuric acid vapor that caused a dramatic two-year drop in temperatures around the world. According to The Chemical Engineer:

As sulfuric acid degrades the ozone layer and is thought to cause regional changes in rainfall, Davidson sought a benign but similarly sized particle. He suggests titanium dioxide, mankind’s most commonly-used pigment. It is stable in air, non-toxic and seven times more effective at scattering light than sulfuric acid. Titanium is abundant in the earth’s crust and we produce 5 million tons per year of the pigment so Davidson does not expect manufacture and supply will be a problem.

With a candidate particle identified, the next challenge is devising a system to effectively and economically lift and disperse millions of tons of particles some 20 km up into the stratosphere, so they stay up for a couple of years and do not immediately get rained out.

His suggested delivery system: giant balloons tethered to ships, which would pump titanium dioxide dust 12 miles into the sky. Simple as that. What could possibly go wrong?

What if everything went right?

Really, though, the question is what could happen if every step in this process went exactly right, and we were somehow able to recreate a Pinatubo-type increase in Earth’s albedo, or reflectivity, by artificial means.

“When you start to reflect light away from the planet, you can easily imagine a chain of events that would extinguish life on Earth,” says David Keith, who teaches engineering and public policy at Harvard, and is said to be among the most thoughtful supporters of geo-engineering solutions like Davidson’s.

That quote is from “The Climate Fixers,” an extraordinary piece by Michael Specter that ran in The New Yorker’s May 14 issue and as of this writing is out in front of the magazine’s pay wall. Here’s the context:

For years, even to entertain the possibility of human intervention on such a scale — geo-engineering, as the practice is known — has been denounced as hubris. Predicting long-term climatic behavior by using computer models has proved difficult, and the notion of fiddling with the planet’s climate based on the results generated by those models worries even scientists who are fully engaged in the research. …

There is only one reason to consider deploying a scheme with even a tiny chance of causing such a catastrophe: if the risks of not applying it were clearly higher. No one is yet prepared to make such a calculation but researchers are moving in that direction.

In addition to cooling the planet overall, Pinatubo’s aerosols dramatically (though temporarily) depleted the ozone layer. They are also thought to have brought devastating drought to sub-Saharan Africa, and to have caused the U.S. summer of 1992 to be the third-coldest and third-wettest in some 77 years, followed by extensive flooding in the Mississippi River basin in 1993 (a detailed paper is available from the U.S. Geological Survey here).

Longer-term manipulation of Earth’s reflectivity could have larger and more persistent regional impacts. Specter’s leading hypothetical is disruption of monsoon patterns in Africa and Asia, where agriculture feeding billions of people has been adapted to cycles that could easily be knocked out of balance, creating catastrophic floods or droughts or both.

Of course, nobody would suggest creating a Pinatubo-type aerosol layer all at once. The more likely strategy would be a gradual, controlled application to add a little reflectivity and see what happens, then dial it up and down depending on the results. Which sounds quite sensible if you assume the dialing would be guided by certainty about how the whole system was responding.

Even then there is the possibility of a nasty surprise. Pinatubo, the second-largest volcanic eruption of the century, was essentially unpredicted until a few short weeks before the magma emerged — and even then the scale of the event could not be forecast.

On the bright side

Already I can hear the global-warming deniers and the incurable technology optimists saying, OK, those are obviously serious downsides – but isn’t it equally possible that science and technology could derive undeniably good outcomes, given a little more time and research?

Specter also discusses some modeling undertaken by climate scientists who were initially skeptical about the whole idea of deflecting solar energy on a global scale. To their surprise, the models suggested it might work rather well — up to a point.

They worked from two key assumptions: a doubling of current CO₂ levels in the atmosphere, which is looking more likely all the time, and a layer of sulfate aerosols sufficient to deflect about 2 percent of incoming sunlight (Pinatubo is said to have caused at maximum a reduction of 10 percent). The results:

Farm productivity, on average, went up. The models suggested that precipitation would increase in the northern and middle latitudes, and crop yields would grow. In the tropics, though, the results were significantly different. There heat stress would increase, and yields would decline. “Climate change is not so much a reduction in productivity as redistribution,’’ Caldeira said. “And it is one in which the poorest people on earth get hit the hardest and the rich world benefits” — a phenomenon, he added, that is not new.

Caldeira is Ken Caldeira of the Carnegie Institution, a principal contributor to the team that won the Nobel Peace Prize in 2007 for the Intergovernmental Panel on Climate Change (Al Gore being the marquee member). Like most scientists, he is candid about the limits of what is known; unlike many climate scientists, he is outspoken about the need for action on a large scale before all the evidence is in.

“We don’t know how bad this is going to be, and we don’t know when it is going to get bad. There are wide variations within the models. But we had better get ready, because we are running rapidly toward a minefield. We just don’t know where the minefield starts, or how long it will be before we find ourselves in the middle of it.”

There is no shortage of other high-tech ideas for solving global warming, from capture and sequestration of power-plant emissions to low-carbon fuels to covering desert landscapes with giant mirrors. Specter’s article introduced a new one, at least for me, which at a glance seemed to have some plausibility behind it.

A company called Global Thermostat has developed a way of breaking CO2 into harmless forms of carbon and oxygen without the high temperatures that have previously made this idea infeasible. This approach would use “a five-story brick edifice specially constructed to function like a honeycomb” to draw CO2 out of the air, then process it with waste heat from, say, factories distributed around the globe. A prototype has been built in California.

It might take as few as 20,000 of these structures, costing only $100 million each, for a total of just $2 trillion, a mere 30 years to make a difference (sarcasm added). Again, it’s a solution that looks good only because all of the others are unthinkable.

The rich and the poor

Global warming’s differential impact on the world’s rich people and poor people, and their differing capacities to adapt, is an important theme running through all serious discussion of climate change’s impacts past, present and yet to come. It doesn’t get the attention it deserves in our national discussions, which tend to center on how avert extinction while preserving our living standards without too much pain or disruption.

Two points in the Specter piece point to the folly of imagining we can truly insulate ourselves from global catastrophe.

  • A ballpark estimate of climate change’s pending economic impact suggests a 5 percent drop in global domestic production, which may not seem like a lot, says Ken Caldeira, until you consider that the subprime-mortgage crisis caused approximately the same drop, whose ripples are still being felt.
  • The atmospheric-aerosols solution could cost as little as a few billion bucks a year – a trifling figure compared to, say, the Global Thermostat approach – and that’s actually the bad news, because it raises the risk of a catastrophic misapplication.

“The technology is open and available—and that makes it more like the Internet than like a national weapons program,” Specter writes. “The basic principles are widely published; the intellectual property behind nearly every technique lies in the public domain.

“If the Maldives wanted to send airplanes into the stratosphere to scatter sulfates, who could stop them?”

A podcast discussion that features Michael Specter and Elizabeth Kolbert, the New Yorker colleague who wrote “Field Notes From a Catastrophe,” is online.

Comments (9)

  1. Submitted by Neal Rovick on 05/15/2012 - 09:02 am.

    The problem is that all of the “fixes” have their own problems:


    Kumazawa, et. al. in their study, “Effects of Titanium Ions and Particles on Neutrophil Function and Morphology” concluded that cytotoxicity (danger to the cell) was dependent on the particle size of titanium dioxide. The smaller the particle size, the more toxic it is (see Table 2). This conclusion is relevant to the consumer because of the cosmetics industry’s increasing use of micronized pigments in sunscreens and colour cosmetics. Nanoparticles of titanium dioxide are used in sunscreens because they are colourless at that size and still absorb ultraviolet light. Many cosmetic companies are capitalizing on metal oxide nanoparticles. We have seen, however, that if titanium dioxide particles used to act as a sunscreen are small enough, they can penetrate the cells, leading to photocatalysis within the cell, causing DNA damage after exposure to sunlight (Powell, et. al. 1996) The fear is that this could lead to cancer in the skin. Studies with subjects who applied sunscreens with micronized titanium dioxide daily for 2-4 weeks showed that the skin can absorb microfine particles. These particles were seen in the percutaneous layers of the skin under UV light. Coarse or fine particles of titanium dioxide are safe and effective at deflecting and absorbing UV light, protecting the skin, but consumers should avoid using products with micronized mineral pigments, either in sunscreens or colour cosmetics.
    (end quote)

    Whatever could go wrong with pumping 10 or 20 million tonnes of titanium dioxide into the air? Naturally, the finer the particle, the longer it will stay aloft, maximizing the effect of the process, but also the finer the particle, the more hazardous it becomes.

    These are all gambles for a desperate last try. Study away, but the true answer is minimizing greenhouse gases.

  2. Submitted by Tim Walker on 05/15/2012 - 09:33 am.

    We’re screwed

    Man, I’ve got to stop reading MinnPost first thing in the morning.

    All the depressing news on this site just ruins my whole day.

  3. Submitted by Lou Singhand on 05/15/2012 - 12:04 pm.

    it reminds me of a friend who, when confronted with the reality that he was “borderline hypertensive”, he began ADDING sodium to his diet so he would go over the limit and be prescribed chemistry so he could keep eating what he wanted.

  4. Submitted by Lance Groth on 05/15/2012 - 12:58 pm.

    We will be forced to it

    The “true” answer, as Neal says, may be reducing greenhouse gas emissions, but the reality is that it’s not happening, it’s not going to happen, and in any case we’re already past the point where emissions reduction could head off the problem. We could have made that choice in the 70’s. Too late now. Not that we shouldn’t do what we can to reduce emissions, but we are past the point where that can constitute anything like a total solution, unless we’re willing to accept a radically changed world.

    Geo-engineering schemes frighten me, but I do think in the end we will be forced to it out of desperation. None of the options look very good, although conceptually I favor solutions along the lines of “Global Thermostat”, i.e., directly removing CO2 from the atmosphere and sequestering it chemically. The cost is daunting, but $2 trillion might look like a bargain as things progress.

    Atmospheric shading with titanium dioxide or any other kind nano-particles is too dangerous and should not be attempted. Besides the obvious problems with toxicity and effects on weather and rainfall patterns, the particles persist for at least a couple of years or so, and thus the effect cannot be “turned off” in the event of a surprise such as Pinatubo. Dumping more pollutants into the atmosphere is not a fix for a pollution problem.

    Orbital shading would be preferable to atmospheric shading since it could be quickly turned off, or tuned up or down, however it would require trillions of orbiting shade devices with a corresponding “astronomical” (pardon the express) cost. Not to mention that all those launches with chemical rockets do the atmosphere no favors, either.

    That would seem to leave CO2 removal/sequestration as the most benign option. Politics will make it far from simple, though, even if it works. Who will be in charge? Who will decide the “correct” amount of atmospheric CO2? I might pick the pre-industrial level of CO2 as the “correct” target, but others genuinely think warmer is better (probably including a lot of Minnesota snowbirds), and would want to reset the thermostat higher. There is even a conservative group that advocates pumping as much CO2 into the atmosphere as possible, because it’s “plant food”. If you thought the Vikings stadium issue was politically difficult, imagine the wrangling over artificially setting the global thermostat.

    I am pessimistic that humanity can summon the political and economic will to do anything until the damage is so obvious and so great, and the horses are so long out of the barn (so to speak), that only desperate, high risk options will suffice, and those will likely have unforeseen consequences. And to the denialists who will undoubtedly show up and attack the article and anything to do with geo-engineering, I say we will only be pushed to high-risk extremes because you were unwilling to do anything about emissions.

  5. Submitted by Frank Bowden on 05/15/2012 - 01:09 pm.

    What could possibly go wrong?

    Sounds great. We could gradually add microscopic particles and see fabulous results in moderating the earth’s temperature. But then another Pinatubo blows, and now we’re feeling a bit too cold…. How long will those particles stay up there?

    This solution also does not address the growing acidification of the oceans. Have they got a plan for that? A critical problem with the emphasis on climate change is that it causes people to ignore the complete basket of environmental consequences that accompany a major change in the composition of the earth’s atmosphere.

  6. Submitted by Leigh Haugen on 05/16/2012 - 07:08 am.

    Warmist Tantrums

    Anthropogenic Global Warming was the greatest scam in world history. Having fought against this scam for almost a decade now it has been interesting to watch as the news coverage slipped from daily mainstream headline news down to the the obscure blogs and op-ed sections where it belongs and will likely continue in perpetuity. AGW is finally the punchline that informed and ethical people always hoped it would become. Money and power, that’s all it was ever about. The hysteria and tantrums of the warmist cult as they sink into obscurity and ridicule has provided some gratifying vindication for those of us who spent years trying to expose the lies and manipulation of those driving the scam. You have to search very hard to even find news converage of the latest Global Warming junket in Bonn. Keep up the great work skeptics! The warmists were on the verge of unelected and unaccountable money and power beyond any dictators wildest dreams – they will not just give up and walk away without a fight! Keep exposing their lies and corruption as they switch to the next great crisis to fleece the taxpayers out of billions more (ocean acidification?)! Nullius in Verba!

  7. Submitted by Dennis Tester on 05/16/2012 - 07:49 am.

    Embrace global warming

    should it ever exist. All life thrives in a tropical environment and dies in an artic one.

    • Submitted by Neal Rovick on 05/16/2012 - 08:19 am.

      Have you ever heard about the Sahara Desert? How about the multi-year drought in Texas?

      Warmer does not mean better. Warmer does not mean wetter in the areas you want wetter. Warmer does not mean more of the creatures and plants you want.

  8. Submitted by William Kus on 05/30/2012 - 10:50 am.

    Not fixing the problem, only the symptoms

    Stop putting impossible and ridiculously expensive band-aids on the problem of Global Warming.

    You are all the reason why the World is so screwed up. You want to treat the symptoms and ignore the problem as it gets worse, causing you to increase your spending on resources towards creating even larger band-aids.

    The problem is not Global Warming, it is what caused Global Warming, not the current symptoms of Global Warming.

    It is the same thing with graffiti in Los Angeles or crime in general. They don’t stop the vandal, they actually encourage the vandal, because it creates a huge industry for the cops and other “Redevelopment” mafias to tell everyone they are REALLY IMPORTANT, BECAUSE WITH OUT THEM WE WOULDN’T HAVE ANY PROTECTION. BUT I DON’T NEED PROTECTION EXCEPT FROM *YOU*.

Leave a Reply