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Researchers Scramble to Create CO2-Busting Technologies

June 8, 2006 at 6:40 PM EST
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PAUL SOLMAN, NewsHour Economics Correspondent: Global warming. Almost all climatologists agree it’s a clear and future danger. Wallace Broecker, a geochemist at Columbia University, has been blaming his fellow humans for over 30 years.

WALLACE BROECKER, Lamont-Doherty Earth Observatory: The way we’re going now, we’re not being responsible. We’re saying, “We want energy as cheap as we can get it, damn the future.”

PAUL SOLMAN: Meanwhile, says Broecker, the world’s population is heading toward nine billion. If current trends continue, carbon in the atmosphere may triple by the end of the century.

WALLACE BROECKER: And triple is something like a six-degree centigrade warming. We would certainly melt the Greenland icecap and probably release the West Antarctic ice sheet, which together would raise sea level about thirty-six feet.

PAUL SOLMAN: Thirty-six feet?

WALLACE BROECKER: Yes. So that would mean all coastal property throughout the whole world would be destroyed, unless you diked it off.

Global warming 101

Rober Elde
University of Minnesota
The carbon that was captured by photosynthesis and is included in the coal was carbon that was in the atmosphere 100, 200 million years ago.

PAUL SOLMAN: Now, Wally Broecker could be wrong, but given the costs if he's right, let's suspend skepticism for the next 10 minutes or so and consider the origin of the greenhouse gases that may be warming the globe and what we might do about them.

First, where do the gases come from? Mainly, it turns out, from the carbon stored up in plants long, long ago.

You may or may not remember from high school biology that plants are fueled by photosynthesis, combining water and carbon dioxide with the help of sunlight.

ROBERT ELDE, University of Minnesota: It's a mixture of coal from Wyoming...

PAUL SOLMAN: So says Professor Bob Elde at the University of Minnesota's power plant.

ROBERT ELDE: The carbon that was captured by photosynthesis and is included in the coal was carbon that was in the atmosphere 100, 200 million years ago.

PAUL SOLMAN: So this is former plants?

ROBERT ELDE: Plant material, that's right.

PAUL SOLMAN: Compressed over the eons, fossilized into coal or oil. That's the simple chemistry behind global warming.

There's no more carbon on Earth than ever before; it's just that much of the carbon absorbed by plants over those eons was easy for humans to dig up and burn above ground to produce energy.

Unfortunately, the burning of carbon, C, combines it with oxygen, O, which resulted in, yes, CO-2, the greenhouse gas carbon dioxide. So, the carbon that it took nature millions of years to bury is resurfacing a lot faster.

A newer carbon source

Robert Elde
University of Minnesota
The carbon that is released to the atmosphere after burning this wood is carbon that is recent, and we say it's carbon-neutral, in terms, as a fuel, because that is carbon that can again be sequestered with a new growing tree.

PAUL SOLMAN: The university is mixing waste woodchips with its coal in order to, in some small way, slow the process down.

ROBERT ELDE: So the carbon that is released to the atmosphere after burning this wood is carbon that is recent, and we say it's carbon-neutral, in terms, as a fuel, because that is carbon that can again be sequestered with a new growing tree, and the cycle goes on and on.

PAUL SOLMAN: Better still would be to mix in or replace the coal with waste biomass that's closer to home and thus takes less fuel to get here, oat hulls, for example, from the local cereal mill.

So that's 25 percent wood, 75 percent coal, and...

ROBERT ELDE: And right here in this little patch, 1 percent oat hulls.

PAUL SOLMAN: The point is, the oats these came from can be readily replanted to reabsorb the carbon emitted into the atmosphere when these are burned.

And that's the beauty of biofuels: They're made from current crops, not the flora of yesteryear, which brings us to what you might call little critter technology.

ROBERT ELDE: This is a Petri dish that contains bacteria that are making, directly from simple plant sugars, petroleum.

PAUL SOLMAN: Are they doing it as we're talking here?

ROBERT ELDE: They are. You can see this little scum on the top is actually...

PAUL SOLMAN: Oh, it looks like oil. It looks like...

ROBERT ELDE: Yes, it's an oil slick. It's an oil slick that is generated biologically, so this is biologically-based petroleum.

PAUL SOLMAN: Again, carbon-neutral because the plant sugars were grown last summer here in Minnesota.

ROBERT ELDE: It simply will put out an equivalent amount of carbon that was taken in last summer.

PAUL SOLMAN: And so the whole problem with fossil fuels is they took in the carbon a long time ago?

ROBERT ELDE: That's right. And that carbon has been sequestered; it's been buried under the ground in an oil field or in a coal mine. And it was taken out from under the ground, combusted, and that carbon is now released.

PAUL SOLMAN: And that's the problem?

ROBERT ELDE: That's the greenhouse gas. That's the cause of the global warming.

An innovative idea

Klaus Lackner
Columbia University
I felt this [capturing C0-2 in the air] is feasible and it should technologically be possible. ... The amount of CO-2 in the air is so large that it actually has a chance of being economically viable.

PAUL SOLMAN: But wait a minute. It's all well and good to slow the process from now on, but what about all the CO-2 that's been released in the past 200 years or so? Some scientists think we've already passed the point of no return with regard to carbon in the air.

WALLACE BROECKER: I think that, no matter what we do, we can't stop it from doubling. If we do very little, we will at least triple it by the end of the century.

PAUL SOLMAN: ... which suggests a major meltdown. So what to do?

KLAUS LACKNER, Columbia University: This is open here, so the air can come in.

PAUL SOLMAN: Broecker's colleague, Columbia physicist Klaus Lackner, is working on one of many solutions: a way to actually remove carbon dioxide from the air. It all started with his daughter, Claire's, eighth-grade science project.

CLAIRE LACKNER, Student: We went to the pet store, and we bought a little fish pump. And then we added sodium hydroxide to the water and just ran this thing overnight with the fish pump, running through the test tube, and then looked back to see in the morning how much CO-2 we collected.

PAUL SOLMAN: They collected enough to get Claire's dad, Klaus, thinking about a real-life application: capturing CO-2 from the air on a scale that would slow global warming.

KLAUS LACKNER: I felt this is feasible and it should technologically be possible. The other thing I realized, the amount of CO-2 in the air is so large that it actually has a chance of being economically viable.

PAUL SOLMAN: From the get-go, Lackner saw the future. Six years later, he's got a simple working model.

KLAUS LACKNER: The most sophisticated part is this little device over here called the GasHound, which actually measures the carbon dioxide content in the air it pulls through.

PAUL SOLMAN: What is it in the outside world?

KLAUS LACKNER: So it is 380 outside. We already passed that. We are now at 520, 530. And it seems to settle around this value, which is a reflection of the fact that lots of people are in here right now.

PAUL SOLMAN: And we're breathing in oxygen.

KLAUS LACKNER: And we're breathing in it. And we are breathing out...

PAUL SOLMAN: We're breathing out...

KLAUS LACKNER: ... CO-2.

PAUL SOLMAN: The rest of the contraption draws air through a solution of sodium hydroxide, which removes carbon dioxide by chemically bonding with it. The little rings extend the surface area to allow maximum bonding.

KLAUS LACKNER: So the air which comes through the fan into here has given up two-thirds, three-quarters of its CO-2, as it blows out here. It's now at 167, 166 parts per million.

PAUL SOLMAN: So it took out three-quarters of the CO-2?

KLAUS LACKNER: Right. Right. Exactly.

The costs of saving the world

Smokestack

PAUL SOLMAN: The idea now is to scale the model up to the size of a football goalpost and suck carbon dioxide out of the air with a vengeance.

KLAUS LACKNER: Such a device could collect the CO-2 from 4,000 people or, alternatively, the CO-2 from 15,000 cars.

PAUL SOLMAN: Because greenhouse gases, once emitted, spread hither thither all over the globe, Lackner says his carbon-capture devices could be planted literally anywhere.

He claims 250,000 of these things worldwide -- admittedly, a huge number -- could neutralize all the carbon dioxide currently being emitted. Half a million could get carbon dioxide back down to pre-industrial levels in a matter of decades, he says. And, as the technology develops, the cost figures to go down.

KLAUS LACKNER: With off-the-shelf items we have right now, I can drive the cost of CO-2 capture from air below $100 per ton of CO-2. And I feel that, if you pursue this longer, the ultimate end game will be below $30 per ton of CO-2.

PAUL SOLMAN: That would be about 25 cents extra for a gallon of gas, says Lackner, but plenty of questions remain: how to cheaply get the CO-2 out of the sodium that's soaked it up; what to do with the CO-2 once you've isolated it.

And if you're going to sop up carbon, mightn't it be better to do so where it gets burned, at power plants, when the air is thick with carbon? But whether it's Lackner's vision or someone else's, the key idea is the same: remove carbon from the air and sequester it back in the ground.

And why not? We've pumped carbon fuels out of the Earth all this time, so there's plenty of room down there for stuffing it back in.

WALLACE BROECKER: We have to really go at it and have a lot of competition so the people who learn how to do it the cheapest and environmentally the safest win out.

PAUL SOLMAN: That might be Klaus Lackner; then again, it might not be.

How many other labs like yours are there in the world, let's say, where someone is doing something that could have a substantial impact on global warming?

KLAUS LACKNER: Probably thousands by now. Without competition, you get some second-best solution and there's no need to make it any better. With competition, it really will get there.

PAUL SOLMAN: In the end, then, economics, which has created global warming, could conceivably save us from it. A comforting thought, anyway, when the next glacier melts down right before our eyes.

MARGARET WARNER: For more information on global warming and to view past installments in Paul's series, visit our Web site at PBS.org.