Enormous 'Parasol' Could Stop Global Warming As scientists search for quicker fixes to the problem of global warming, some have been studying a technique they compare to a parasol. Ken Caldeir of the Carnegie Institute explains a plan for blocking some of the sun's rays.
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Enormous 'Parasol' Could Stop Global Warming

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Enormous 'Parasol' Could Stop Global Warming

Enormous 'Parasol' Could Stop Global Warming

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Today marks day three of the international climate talks in Bali. One of the emerging issues is the fact that a bunch of the richer countries who are supposed to lower their greenhouse emissions by next month will probably end up just paying extra money for the right to keep polluting at the higher rate. This has not been sitting well with some of the less-rich folks at the conference.

But what if there was a scientific solution to the problem so bold, so new, that it could help make things better for everyone here on terra firma, regardless if they were in a country of haves or have-nots? Well, such an idea would go perfect in the series we're running this week which we're calling…

(Soundbite of song, "Theme from The A-Team")

BURBANK: It's So Crazy, It Just Might Work.

Monday, we heard about building huge mechanical trees to absorb CO2. Yesterday, it was dumping metal shavings into the ocean to feed a giant, living carbon filter. Today, a giant parasol to block the sun's rays - except this one is not made of pink taffeta or ostrich feathers - although that would be beautiful, if you thought of that.

STEWART: Stunning.

BURBANK: I talked yesterday with Ken Caldeira of the Carnegie Institution's Department of Global Ecology.

STEWART: You loved this guy.

BURBANK: This guy was awesome. He explained - this is why, because he explained that we could actually block out some of the sun's rays and cool the Earth by sending tiny particles - sulfates, for example - into the upper reaches of the atmosphere.

Professor KEN CALDEIRA (Department of Global Ecology, Carnegie Institution): You could make it out of almost anything. The cheapest thing is probably sulfur particles. But, really, any tiny little particles high up in the atmosphere will deflect sunlight away from the Earth, back to space. And since sunlight is what warms the Earth, deflecting some of that sunlight back to space would help keep the Earth cool.

BURBANK: Immediately, what comes to mind when you say that, though, is my, you know, fifth grade memories are that that's what caused the ice age. Could you take this too far?

Mr. CALDEIRA: Well, the particles in the stratosphere - which is the upper part of the atmosphere - last a year or two or so. So if we put in a little bit too much, they would rain out within, say, a year or two. And we could look at how the climate is changing in response to this, and if it seems like we were overdoing it, we could back off and operate the system like that. There would be some kind of process, we'd put some particles up there, see how the climate responds, and then adjust what you're doing depending on that response.

BURBANK: How would you get these particles up into the atmosphere?

Mr. CALDEIRA: There are a whole bunch of different ideas that have been suggested. In 1992, there was a report from the National Academy that suggested we could use artillery shells to send it up. We could drop it out of airplanes. Some people recently have suggested we could suspend a big hose from balloons up…

BURBANK: You wrote about that in the New York Times. I loved that you are a serious scientist, and that you wrote in the New York Times as an op-ed that maybe a way to do this is through hoses off of balloons.

Mr. CALDEIRA: Yeah. It sounds crazy, and I'll admit that.

BURBANK: Maybe so crazy, that it might work.

Mr. CALDEIRA: It might be just crazy enough to work. It's thought that any reasonable approach might cause something on the order of a billion dollars a year, which is a lot of money for you and me. But compared to what it would cost to transform our energy system, it's really cheap.

BURBANK: It seems like it would take a lot of material to sort of cover the whole globe and cover the Earth's entire atmosphere and have any real effect. It just seems so huge. And yet you write that a five-gallon bucket per second of stuff would do it, and that doesn't actually sound like that much to me.

Mr. CALDEIRA: Yeah. Depending on exactly what kind of particles you use, it could be 10 times as much as that or somewhat less, you know, one-one thousandth or one-ten thousandth of the amount of carbon dioxide we're releasing each year. And so it's certainly the scale of things we do all the time. The secret is to make little tiny, tiny particles, because little tiny particles have lots and lots of surface area and they reflect a lot of sunlight back to space.

So the total amount of stuff that we're talking about putting into stratosphere is something like, you know, less than what Mt. Pinatubo put into the stratosphere in 1991, and that was a big volcano in the Philippines.

BURBANK: Right. And this is part of the story of this idea, right? Like, this volcano happened in the Philippines, and there was a measurable effect - at least in that area - on temperature?

Mr. CALDEIRA: Not just in that area, but throughout the globe. There was a cooling after that volcano. That volcano put up enough particles into the stratosphere to essentially reverse many of the effects of the doubling of atmospheric CO2, and we didn't see anything really catastrophic happening.

BURBANK: Would the daytime be noticeably darker if this system was in place?

Mr. CALDEIRA: No. You know, in 1991 and 2, after this volcano, what people noticed was that sunsets were more spectacular, because having the particles in the stratosphere refracts the sunlight and produces more spectacular sunsets. So I don't think anybody would notice anything different during the day. What they would notice is spectacular sunsets.

BURBANK: Well, this, I have to say, sounds like a real panacea. I mean, you pump a bunch of, you know, stuff up into the atmosphere. You have beautiful sunsets, the temperature drops. It's only a billion dollars a year. We're in clover, right? Or are we?

STEWART: I know…

BURBANK: What's the possible downside?

Dr. CALDEIRA: Yeah. I mean, I think there's a few issues. And the first one is, you know, our climate models are very complex, but the Earth is far more complex than any of our climate models.

And the history of humans intervening with things on a large scale is not very encouraging. You know, we think of having the CFCs that we were using to work in our refrigerators could destroy the ozone layer. The lead in gasoline, which were making engines work better, and then destroying children's brains. Or in Australia, they, you know, introduced different species that try to eat another species and now they have king toads all over the place.

And so, the success of humans doing things in the large scale and being able to predict what the effects would be has not very encouraging.

The other point is that a quarter of that CO2 that comes out of your tailpipe will still be in the atmosphere a thousand years from now. And, you know, are you really going to be making sure your great, great, great, great, great, great, great grandchildren are going to still be geo-engineering the planet to cover up for your automobile that you drive today?

I think we should just assume that when we interfere with the planet at large scale that unanticipated things will happen. So I don't really see this as an alternative to reducing greenhouse gas emissions. I see it as an emergency response plan. When a doctor treats somebody with a disease, you can first try to cure the underlying cause of the disease, but you can also treat some of the symptoms so that the patient doesn't feel so bad.

And so I think of greenhouse gas emissions as the underlying cause of our planetary disease, and I see these geo-engineering schemes as kind of a symptomatic relief. And so, while symptomatic relief might be necessary at some point, we do need to work at curing the underlying disease.

BURBANK: Well, if the underlying disease, then, is all of the carbon that, you know, is being used mostly as an energy source and then getting kicked off into the Earth's atmosphere, I want to ask you about something else, which I want to call It's So Crazy, It Might Work Bonus Round, which is if there was a way to not need all that carbon to power things - such as I've read you talking about harnessing wind in the atmosphere. I read an amazing quote from you that you said if there was a way to do that, we could power the entire Earth's energy needs with a small amount of what's happening - please, do explain. How would this work?

Dr. CALDEIRA: The winds high in the atmosphere are much stronger than the winds near the surface. Anybody who has flown a plane from New York to San Francisco, for example, knows that you hit a strong headwind. And the energy in this wind is really enormous. The energy in the jet streams is about a hundred times the total amount of energy used by all civilization. And so if we could tap into just one percent of that energy, it would be enough to run civilization.

Google has recently funded one company to try to figure out ways to tap into this. And the basic idea is that you could essentially have a kite with a wind turbine on it or a gyrocopter acting as a wind turbine, and then run the electricity down the tether, and, you know, the basic engineering analysis suggests that it should work, and there's huge amounts of energy available. It's one of these things that sounds like science fiction, but, you know, if you look into it, it seems like it all make sense.

BURBANK: It's amazing, because the ideas that you're describing seem to be so kind of elegantly simple, and, you know, to me, anyway, the layman, they sound like they make a lot of sense.

When you're at a party, though, when you're talking about, you know, harnessing the jet stream with a giant solar sail turbine or, you know, shooting, you know, bits of sulfites into the atmosphere to lower the temperature, do people just think you're drunk?

Dr. CALDEIRA: Well, sometimes I might be drunk, but…

BURBANK: I guess that's a possibility, right?

(Soundbite of laughter)

Dr. CALDEIRA: Yeah. But in the cases when I'm not, you know, it's one of these things where, when people first hear about it, it sounds crazy. And then you'll learn a little more about it, and it starts making a lot of sense.

You know, I think the range of the possible is much bigger than our imaginations, that if you would think people in the year 1900, you know, if you told them that we would be regularly flying in jet planes and that, you know, we would have computers in our cell phones and, you know, all this kind of thing, that they would think it was science fiction.

And these kinds of things wouldn't have even been in their imagination. And so I think sometimes we make the mistake of thinking the future is going to look like some kind of small variation on the present. And, you know, just in the same way that the things we use commonly today were beyond the imagination of people 50 or 100 years ago. There are things that people will be using routinely 50 or 100 years from now that are beyond our imagination.

BURBANK: That's Ken Caldeira of the Carnegie Institution's Department of Global Ecology. And if you've been enjoying this series like I have, you're going to want to go to our Web site and check out this terrific video that our video producer Win Rosenfeld made. He visited this lab where scientists are experimenting with a prototype carbon dump.

This here's the thing, Alison. Let's say you actually manage to go capture CO2 that's in the air.

STEWART: What the heck do you do with it?

BURBANK: Yeah, what'll you do with it? Where you're going to put it? How long is it going to stay there? That's kind of the second - whenever I talk to these guys that were trying these different revolutionary things, particularly in the last couple of days, the question then became, well, still, what are going to do with the carbon?

So Win went to where there's this thousand-foot hole. I think it's in upstate New York, he told us yesterday.

STEWART: No, I think it is at by Columbia University…


STEWART: It's in this…

BURBANK: I thought he said it was on some other campus.

STEWART: Oh, you know what? It's another campus, but it's not that far outside of New York City, by the Palisades.

BURBANK: Shows you…


BURBANK: …lack of knowledge about New York geography. But anyway, you're going to want to go to our Web site and check out this video. And if you want to check out the rest of the series as well, It's so Crazy, It Just Might Work -or if you grew up on the West Coast like I did, It Just so Crazy, It Might Work. That was another big topic of discussion.

STEWART: Mm-hmm. Got you. Hey, so, I listened to the debate - the NPR debate, on the computer machine.

BURBANK: Hmm. Sure.

(Soundbite of laughter)

STEWART: While I was…

BURBANK: You got a computer machine, huh?

STEWART: …paying the bills and filling out - it was really rather interesting to hear the candidates only talk about three subjects, and have to talk about them in a substantive way…


STEWART: …and with long answers, and have to disagree with each other on policy points and not just, I know you are, but what am I?

BURBANK: And Michele Norris of ALL THINGS CONSIDERED kind of put John Edwards on the spot, right?

STEWART: Got a little spicy in there. Got a little bit spicy. We're going to talk about that. We'll also talk about, oh my gosh, how prescient were they to make Iran one of the topics, considering the NIE report came out yesterday? So that made for a nice little interesting mix-up. There was a little bit of Iowa caucus goer butt smooching, as well.

They did remember where they were, in Iowa, and that the caucus is only a month away. So we'll play you some of the highlights in case you didn't hear it. Of course, you can always download it at npr.org. Stick around.

You're listening to THE BRYANT PARK PROJECT from NPR News.

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