IRA FLATOW, host:

For the rest of the hour, CO2, carbon dioxide. There's a lot of talk these days about reducing carbon emissions, but what about catching those CO2 emissions before they billow out of smoke stacks and into the atmosphere? Scientists are already thinking about the best way to do that. Of course, once you capture the stuff there's that problem, a slight little problem detail, where do we put it? There's always been talk lately about putting it underground. "Sequestering it" is the catch phrase. But there is fear that all that CO2 might leak out someday, come swishing back up in a ground-hugging suffocating blanket.

Well, now there is another more creative idea. A group of researchers say that they have perfected a place to put it safely away in cavernous volcanic rock beds nearly 10,000 feet underwater, under the Pacific Ocean. They say that these basalt formations off the coast of Oregon and Washington have huge empty cavities capable of locking in carbon dioxide harmlessly, and these pockets could be extensive enough to store up to 150 years of U.S. CO2 emissions. But how do you get the CO2 down there and what stops it from just bubbling back up through the water? That's the most interesting part.

We'll talk about that. Joining me now to talk about the possibility of storing carbon emissions deep under the ocean, under the sea floor, that's research is out now in the journal Proceedings of the National Academy of Sciences, is Dr. David Goldberg. He is a geophysicist at Columbia University's Lamont-Doherty Earth Observatory. He joins us on the phone today from Texas. Welcome to the program, Dr. Goldberg.

Dr. DAVID GOLDBERG (Geophysicist, Columbia University): Good afternoon, Ira. How are you?

FLATOW: Good afternoon. How did you come up with this? Give us the ABCs of how you do this.

Dr. GOLDBERG: Well, first of all, we were looking at a downstream solution that was sufficiently large to deal with a huge climate problem. And one of the options that came to mind being a marine geologist, geophysicist was looking below the seabeds. And that indeed is something that - this area offers is a very well studied seabed, and it basically has a vast repository of basalt layers that have large cavities at least large volumes. The cavities themselves are more like fissures and gaps, but it will fill, and it will hold a lot of fluid.

FLATOW: Well, let's talk about the physics of what happens. Let's say you pump this stuff down into the basalt. Does it go into the water, does it go right into the rock? What happens to it?

Dr. GOLDBERG: Well, what we've considered here in this report, for this research is pumping in pressurized and liquidized CO2 directly into the basalt that is open and coarse. It then will dissolve into the existing fluids that are in those rocks which is predominantly seawater and various minerals that are mixed with the seawater and remain there for a period of time. That's the attraction of this location is that it can remain there, we feel, fairly securely for decades and centuries while it reacts with those rocks and with the seawater. And that's what - there's a really nice attraction, that chemical reaction will leave it in a form that is permanent and a benign carbonates essentially chalks that fill those pores over time.

FLATOW: So, you turn the CO2 into chalk?

Dr. GOLDBERG: Effectively, those are the minerals that will be reacting. It's iron and calcium in the rocks in the seawater that will react with the dissolved CO2.

FLATOW: And it locks itself into the basalt?

Dr. GOLDBERG: Yes. That's exactly what happens. It deposits itself in those open spaces. The rates of all those processes are what we're considering examining in more detail with a pilot experiment. But the potential is there, our laboratory and local field tests show that those processes happen at a reasonably fast rate and they are basically permanent and benign.

FLATOW: So, there's no fear of it bubbling out again because you have chalk instead of CO2?

Dr. GOLDBERG: Ultimately, yes. That's exactly the idea, permanent and secure. In the meantime while that process is happening, the advantage of the basalt under the ocean is that it is in the area that we've identified, it's kept very well by sealing fine-grained sediments. And that will keep it in those basalt formations while those chemical reactions take place, we believe, for a sufficiently long time, and then in fact that will be an additional seal protecting the oceans from escape.

FLATOW: So, you have layer upon layer like a big club sandwich.

Dr. GOLDBERG: Yeah, you could call it a nice sandwich, and hopefully it won't have leaks. If it does, anything unexpected happens, we're also very deep which is - has a nice advantage in that CO2 in liquid form will become more dense than seawater at those depths. So, if there's a little inadvertent leak, it will essentially tend to sink up into the sediment and not escape out into the ocean.

FLATOW: So, you're talking about 10,000 feet below the surface. Something like that?

Dr. GOLDBERG: Approximately, yup, 2,800 to 3,000 meters, yup.

FLATOW: Wow. And is it true that there's enough space down there that you could take all of the 150 years worth of CO2 emissions?

Dr. GOLDBERG: Well, we looked at an area that had the appropriate depth and sediment cover, and we used the existing data from decades of experimentation out in that plate, a wonderful(ph) plate off the coast of Oregon and Washington and estimated those volumes, and they are large. There's 200 billion tons or more of volume space for filling. And indeed that if the U.S. stays at its current emission rates for a sense of the size of this reservoir, that's upwards of 120 to 150 years of current rate U.S. emissions. If those rates go up, of course, which we hope that they don't, but that would shorten those numbers of years. But it's a very large reservoir and certainly one of the big attractions.

FLATOW: Well, you're pretty close to the shoreline of California or even Oregon CO2. What would you do with New York's side? You're talking about piping it across or liquefying it and traveling it?

Dr. GOLDBERG: Well, indeed that's probably for the global solution though that there's other reservoirs that would be much more practical in the sense that I gave you for the U.S. is just to give you a sense of the scale. But it is a viable solution we think by pipeline from say West Coast sources of emissions once they're captured.

FLATOW: Talking about CO2 sequestering under the ocean floor this hour, Talk of the Nation Science Friday from NPR News, David Goldberg from Lamont-Doherty Earth Observatory. Of course, there's basalt all over the ocean, all over the world, right? On the seabeds?

Dr. GOLDBERG: Indeed, the entire ocean is comprised of basaltic lava at the top of the crust. It's what forms it at the upper crust layer, and it is not - it's just a question of what depth it's at and how long it has been buried and overlain by additional basalt and sediment. So, it's everywhere. But in the ocean area offshore Oregon it's at the appropriate depth and still has a remainder of volume and pore space that will keep CO2 flowing. As basalt gets older in the ocean and there's piles and piles of sediment on it, of course, it can be miles below the seabed, first of all, which is not very accessible, much less accessible. And more importantly, it will be filled by a natural process which is weathering of the basalt by seawater. And that does exactly the same thing which is precipitate depositing, carbonate and chalks, and other minerals in the open-pore spaces.

FLATOW: Is this cost-effective? I mean, would people say, hey, you know, it's cheap enough to do this and is it energy neutral?

Dr. GOLDBERG: Well, it certainly is not going to be the easiest solution being offshore for one and being that there's infrastructure of drilling and piping and pumping that would need to be installed. But the size of the problem is so large that that will have to be dealt with in some place ultimately no matter what the final repository for the CO2 is. So, we felt that looking at the security here and putting a value on the security of the solution as well as the size of it, the fact that it is a large repository in this one location, really has value that would depend on how efficient that whole industry as the sequestration becomes over time.

FLATOW: And you think it's a better solution than pumping it back underground and all the oil wells and things like that.

Dr. GOLDBERG: Well, it's a larger solution. It's the first really significant size solution that I think we've put out there that has a viable size to make a dent in the problem.

FLATOW: And you have a test bed that you're working on?

Dr. GOLDBERG: A test bed.

FLATOW: You have a site that you're experimenting on?

Dr. GOLDBERG: Well, the area that we're looking at is of course an area that we've studied for - many researchers have studied for quite some time, decades. And we have an idea to go back and do a pilot experiment by reoccupying one of those existing sites and actually look at the fate of the CO2, a small-scale experiment over time.

FLATOW: At Lamont-Doherty, you have one? You have one up there in your lab that you've tested out?

Dr. GOLDBERG: We've looked at the rocks that are similar to basalt and certainly in the laboratory at Lamont-Doherty. And looked at those areas for the study of how fast those reaction rates occur. It's not in the undersea - exactly the undersea formation.

FLATOW: Right.

Dr. GOLDBERG: But we got a good sense of what we think is going on and that was a big piece of this research and putting it forward.

FLATOW: Dr. Goldberg, I want to thank you for taking time to be with us.

Dr. GOLDBERG: You're very welcome. Thank you for the opportunity.

FLATOW: And good luck. We'll follow the progress. Dr. David Goldberg is a geophysicist at Columbia University's Lamont-Doherty Earth Observatory. And if you're having trouble visualizing the storage process, Flora Lichtman, our digital producer is here to help us. Welcome to Science Friday.

FLORA LICHTMAN: Thanks for having me, Ira.

FLATOW: Now, you actually went out to Dr. Goldberg's drilling site.

LICHTMAN: That's right.

FLATOW: Where was that?

LICHTMAN: It's out in Palisades, New York. It's about an hour outside New York City. And, yeah, I took a look at their bore hole.

FLATOW: They have a bore hole that he talked about and you made a video out of that.

LICHTMAN: Yeah. So, they have a bore hole in the backyard of Lamont-Doherty and it goes down a thousand feet into basalt. And so they can try out, as I understood it, some of these ideas there.

FLATOW: And you went there, you videoed it. If you go to our Web site, it's sciencefriday.com it is the video pick of the week.

LICHTMAN: Right.

FLATOW: And you actually made a model of that sandwich I talked about in your kitchen, but you didn't use a sandwich.

LICHTMAN: Yes. Well, I thought it was a little hard to imagine what this might look like under the sea. So, yes, so I made a model using breakfast cereals and yeah, I think that's all, that's it.

FLATOW: Layers of breakfast cereals.

LICHTMAN: You know, just take a look.

FLATOW: They'll have to take a look. Go to our site, sciencefriday.com, look for the video pick of the week and we have all kinds of videos there, and you can see Flora Lichtman's terrific creative design. Thank you, Flora.

LICHTMAN: Thanks for having me.

FLATOW: Greg Smith composed our theme music. With help today from NPR librarian Kee Malesky and from Ron Curtis and Jenny Lawson (ph) at WWNO. Surf over to our Web site at Science Friday. You can now see Flora's video of breakfast cereal and her kitchen imitating this bore hole, it's quite interesting. I think you'll learn a lot from it. Also, other videos are there, podcast and blogging and also you can leave us email there. And we're looking for more of your videos. If you see Flora's video and you like it, and you want to make one of your own, please send it to us. We're more than happy to take a look at it and see if we can put it up on our Web site. Have a great weekend. We'll see you next week. I'm Ira Flatow in New York.

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