Wallace Broecker Geochemist, Palisades, New York
How to stop global warming? CO2 "scrubbers," a new book says
- By Kenneth R. Fletcher
- Smithsonian magazine, June 2008, Subscribe
Wallace Broecker, of Columbia University's Lamont-Doherty Earth Observatory, first warned in the 1970s that the earth would warm because of a buildup of carbon dioxide and other gases released by burning fossil fuels. In his new book, Fixing Climate (co-authored by Robert Kunzig), Broecker, 76, argues that we must not only reduce emissions of carbon dioxide (CO2) but also remove it from the atmosphere on a massive scale to avert environmental ruin. He is an unpaid adviser to Global Research Technologies, a Tucson firm developing devices to capture CO2 from the air.
By the 1970s, you already believed that CO2 from emissions was causing global warming.
Looking at the earth's past climate told me that the earth is very sensitive to changes. It concerned me that as we warmed the planet we were heading into unknown territory. I've convinced myself that it is going to be absolutely necessary to capture and bury CO2. The best way to do that is to take it directly out of the atmosphere.
How do you "fix" climate?
We need something that can be manufactured, like air conditioners or cars, by the millions. Each day, a unit would take about a ton of CO2 out of the atmosphere, liquefy it and send it out through pipes to wherever it's going to be stored. The developers are now envisioning a device about 6 to 10 feet in diameter, 50 feet high. It would be like a little silo, in that shape so the wind could blow through it from any direction.
CO2 emissions are going up faster than the highest scenarios. Developing nations are going gangbusters using fossil fuels, so they are eclipsing any savings that the rich nations are making. At some point we are going to have to get tough about it. There is going to be a demand to bring the CO2 level back down again because of the environmental damage it's doing. The only way to do that would be with this sort of device.
How many devices would be needed?
Each of us in America is responsible for generating about 20 tons of CO2 a year. So I suppose roughly 17 million scrubbers would take care of the United States. Worldwide, we'd need a lot more. On a long time scale the rich nations can do more than just stop or neutralize their own emissions. They can also neutralize some of what was done in the past.
The scrubbers don't have to be near the source of pollution?
No. They can be put anywhere. The units would operate best at low humidity and would be best deployed in deserts.
What happens to all the CO2 the scrubbers take out of the air?
There are many places to store it. The most obvious is the saline aquifers that are under every continent. Ultimately, I think we'll want to put CO2 into the deep sea. We at Columbia are exploring with Icelanders the possibility of injecting CO2 dissolved in water into basaltic terrains that make up the earth's mantle, to combine the CO2 with magnesium and convert it into a mineral. One has to figure out a clever way to do this without using a lot of energy.
Of course, this whole thing has been a race against time. We have done relatively little since 1975, when I first became really concerned about climate change. People say Kyoto was a great accomplishment. It trimmed production of CO2 a bit, but it's just one percent of the solution. We've got a huge distance to go.
Is this safe?
We're going to have to prove that. People aren't going to want CO2 underneath their houses unless they can be assured that it's not going to come back in any violent way. I think it would be easier to convince people that putting it in the deep sea is safe.
We have to do something. Otherwise we're going to have a very hot planet and the environmental damage is going to be huge. Any solution is going to have its own environmental consequences. We have to make sure those are very small compared to the consequences of doing nothing.
What about alternative energy sources?
I don't think anybody believes that alternatives will supply the energy we'll need. The long-term solution is solar electricity. But it is far too expensive—there have to be breakthroughs. If they were to occur in the next 10 or 20 years, great, we could put the whole CO2-capture idea on the shelf. But we have to develop that technology, because it looks right now like solar energy is not going to become affordable in that time scale. We are going to need some way to bail ourselves out.
We have enough coal to run the planet for several hundred years. We could make gasoline out of coal for the equivalent of $50 a barrel. People are not going to use solar energy if it costs 10 times more than energy derived from coal. We are not putting enough resources into developing the technology to capture and store carbon. Everybody is worried about carbon footprints as if that is a solution. It's not. It is important, I'm not putting that down, but conservation in itself can't do it. The world has to run on energy.
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Comments (36)
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Have you considered calcium carbonate (ie limestone)for storage? Perhaps someone could fiddle with diatoms to get them to make heavier shells. Grow them in ponds with extra carbon dioxide. Eventually the ponds would fill up with pre-limestone.
Posted by kathie biddle on November 27,2009 | 04:49 PM
Isn't there a not very unhealthy chemical substance that can be given into the atmosphere, bind CO2 at it and cause a precipitation of it that can be disposed somehow?
Posted by Henry on July 9,2009 | 01:24 PM
I am an electrical engineering student with an avid interest in pro-environment solutions.It seems to me that the final solution(if one exists)must come from what is naturally available itself.Any and all external solutions will change energy levels in some form and this change will then have to be dealt with like the current CO2 problem...am i wrong?
Posted by Aaron Brito on May 5,2009 | 01:37 AM
I thank the authors for an excellent book about our planet's climate. Defining and presenting the "Ocean Conveyor" is a tremendous scientific contribution providing a basic understanding of how oceans circulate heat.
Regarding our future climate, I suggest that the Arctic Ocean is our planet's biological thermostat--- in combination with Wallace Broecker's concept of the "Ocean Conveyor"
Thermodynamically, I suggest that ice---(both Arctic & Antarctic plus all glaciers) which needs latent heat of fusion to melt--- is our temporary insurance policy that prevents some type of 'tipping point' for our planet's climate. When that policy runs out ( when the Arctic Ocean loses all ice---perhaps by 2025) we may be in for the start of a new ice age as previously hypothesized (Ewing-Donn theory...circa 1958 @ page 44 of the book).
CO2 scrubbers to capture and reduce CO2 concentrations in the atmosphere? A possible, but maybe not practical solution to the problem.
As an engineer, I suggest gradual conversion to more efficient energy service provision including CO2 isolation as a nearly pure byproduct. Some of this is described in my 1996 US Patent 5,537,823.
This patented heat flow process is capable of isolating CO2 at the point of origin as a byproduct of combustion.
Technologically, why not try stopping the largest CO2 discharges to the atmosphere at their point of origin.
Respectfully posted April 18, 2009
Richard H. Vogel
Posted by Richard H. Vogel on April 18,2009 | 12:19 PM
Hi I'm very interested in the cause of reducing global warming. Whether or not it is right we at least have to try. I'm trying to build a device for home use by everyone using technology similar to the carbon scrubbing trees. I'm still researching the plastic that is used to absorb the co2 form the air. I've got some basic facts, like the plastic/resin holds the co2 in the form of sodium bicarbonate in the plastic/resin. Does anyone know what the plastic is, it's chemical make up or basically what it is called any help would be much appreciated I want to try and make it on my own, but I have no Idea what is is. Only that its been used in water purifiers or softeners for several years.
Posted by dcab on December 14,2008 | 06:28 PM
Dear Mr. Broecker, I love this article!!! I you could send me everything you have on carbon scrubbers it would help me with my First Lego League project a lot!!!!thanks sincerely Hannah Graham
Posted by ann on November 20,2008 | 04:26 PM
Thinking about this idea I thought about a step further, for example, how to turn that carbon dioxide in something stable and firm like sooth or graphite, which are forms of carbon and release oxygen as bi-product.
Posted by Dusan Miric on October 11,2008 | 04:56 PM
I have seen a documentary on Frozen CO2 Rockets being dropped/"shot" into the deep ocean where they will stay frozen under the deep pressure,hopefully. My question to Mr Broecker and other scientists working on this type of project ia a simple one, but there may not now be a simple answer. Once you have the CO2 sequestered, why not break it down into simple carbon and O2. We sure could use the O2 in the atmosphere and the carbon can be used industrially, or at least it would not be harmful. Let someone come up with an economical way to do this and there would be an overall benefit immediately, and no diaposal problems. After all, you could even sell/give the pure carbon to one of the companies that makes diamonds. Just think -- diamonds out of pollution!
Posted by Lyle Morrow on October 10,2008 | 10:55 PM
I am impressed with the young man's idea about feeding food producing plants with CO2 as a way to extract it from the atmosphere and put it to use instead of hiding it somewhere that might not be able to contain it forever. This young man(Mark Goergiou) an apparently bright indvidual that may someday be a scientist I, for one am pleased to see someone so young interested in saving the planet and feeding the hungry. Kudos to you mark, keep thinking and study hard. I'm sure you will go far
Posted by Frank Sanford on September 26,2008 | 10:16 PM
I have been interested in the rise of Global Warming for A long time(going to college long ago in Environmental Science-although I graduated with a degree in a different field). Any information-or such-in the subject, may be of definite interest; it seems often difficult to obtain specifics, in the area, itself. -Steve
Posted by steve on August 29,2008 | 12:41 PM
hi im mark i am 13 years old. i was just reading this becaus i had an idea of extracting the co2 emmisions from the air and basicly feeding it to a facility that has plants in a secure area were the co2 cannot escape. So becaus the plants need co2 to live why not feed it to them. And it has been scientificly proven that plants will produce twice as much fruit or better yet twice the size of the fruit. Wich in the end will hit two birds with one stone. thus trying to end world hunger at the same time. hope you like my idea. yours sincerly mark goergiou.
Posted by mark goergiou on August 21,2008 | 09:31 AM
I find it hard to believe that a car produces 1.4 tons of CO2 per mile as suggested by Ken Meshke. Maybe I'm wrong but that doesn't seem to make any sense to me. Where does it all come from?
Posted by tom on August 17,2008 | 07:10 PM
The best sink for carbon would be Diamonds, about 2 cubic kilometers per year, either one big gem, or a pile of diamond beach sand. In hot weather the diamond beach would be hot on your soles (diamond is an excellent conductor). And about the energy source to make the diamonds? Just use the same (unspecified) energy source that Broecker would use.
Posted by g bruno on July 15,2008 | 07:00 PM
What nonsense! An over-technical solution if I ever heard of one. georgeof420 was right -- trees do this much better than any machine. Yes, left on their own they will eventually return the Co2 to the atmosphere -- but not if we carbonize them! Better yet, carbonize friable biological materials like leaves, and add that to soil to make it hold nutrients better, reduce run-off of fertilizers, retain moisture, make nutrients available for plants increasing crop yields (which also holds more Co2, at least temporarily). It's called BIOCHAR folks, and instead of being expensive it saves money, instead of being technological it can be grass-roots, instead of being forced on communities it will be enthusiastically adopted if the benefits (not even including the resultant carbon sequestration we are talking about) are made known. Of course you can take biomass gasses to produce fuel, in which case it does become technological -- but not dauntingly so. Alternatively those gasses can be used to make the carbonization more efficient, with nothing more than a barrel and some tubing. Biochar is the only carbon-negative process that can also be profitable, ensuring its widespread adoption. All that is needed is education.
Posted by A J Morris on July 11,2008 | 01:58 AM
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