Deep-Sea Sediments Could Safely Store Man-Made Carbon Dioxide

Terra Daily ^ | August 17, 2006 | Staff Writers

[cogitator]

An innovative solution for the man-made carbon dioxide fouling our skies could rest far beneath the surface of the ocean, say scientists at Harvard University.

They've found that deep-sea sediments could provide a virtually unlimited and permanent reservoir for this gas that has been a primary driver of global climate change in recent decades, and estimate that seafloor sediments within U.S. territory are vast enough to store the nation's carbon dioxide emissions for thousands of years to come.

Harvard's Kurt Zenz House and Daniel P. Schrag, along with colleagues at the Massachusetts Institute of Technology and Columbia University, detail the advantages of sequestering excess carbon dioxide thousands of meters beneath the ocean's surface in this week's issue of the Proceedings of the National Academy of Sciences.

"Supplying the energy demanded by world economic growth without affecting the Earth's climate is one of the most pressing technical and economic challenges of our time," says Schrag, professor of earth and planetary sciences in Harvard's Faculty of Arts and Sciences and director of Harvard's Center for the Environment.

"Since fossil fuels -- particularly coal -- are likely to remain the dominant energy source of the twenty-first century, stabilizing the concentration of atmospheric carbon dioxide will require permanent storage of enormous quantities of captured carbon dioxide safely away from the atmosphere."

Schrag and his colleagues say an ideal storage method could be the injection of carbon dioxide into ocean sediments hundreds of meters thick. The combination of low temperature and high pressure at ocean depths of 3,000 meters turns carbon dioxide into a liquid denser than the surrounding water, removing the possibility of escape and ensuring virtually permanent storage.

Injecting carbon dioxide into seafloor sediments rather than squirting it directly into the ocean traps the gas, minimizing damage to marine life while ensuring that the gas will not eventually escape to the atmosphere via the mixing action of ocean currents.

At sufficiently extreme deep-sea temperatures and pressures, carbon dioxide moves beyond its liquid phase to form solid and immobile hydrate crystals, further boosting the system's stability. The scientists say that thus stored, the gas would be secure enough to withstand even the most severe earthquakes or other geomechanical upheaval.

Other researchers have proposed storing carbon dioxide in geologic formations such as natural gas fields, but terrestrial reservoirs run a risk of leakage.

"Deep sea sediments represent an enormous storage reservoir," says House, a graduate student in Harvard's Department of Earth and Planetary Sciences. "Some 22 percent, or 1.3 million square kilometers, of the seafloor within the United States' exclusive economic zone is more than 3,000 meters deep. Since we estimate that the annual U.S. emission of carbon dioxide could be stored in sediments beneath just 80 square kilometers, the seafloor within U.S. territory could store our nation's excess carbon dioxide for thousands of years to come."

Outside the United States' 200-mile economic zone, the scientists write, the total carbon dioxide storage capacity in deep-sea sediments is essentially unlimited.

The scientists note that thin or impermeable sediments are inappropriate for carbon dioxide storage, as are areas beneath steep deep-sea slopes, where landslides could free the gas. They add that further assessment of the mechanical feasibility of delivering carbon dioxide to the seafloor, as well as study of possible effects on sea levels, is needed.

[cogitator]

And if we are in danger of running out of CO2 for soft drinks, we can always put in a pipeline to the seafloor to get the stored CO2.

I have to note that saying CO2 "fouls our skies" is a bit over-the-top. Soot and smoke foul the skies; CO2 just alters the atmosphere. Now, if they'd said "souring our skies" instead, that would have been very clever!

[kinoxi]

Deep sea is a long way down.

[NonValueAdded]

newsflash, 2015 ... the SS Minnow was discovered by a UN Coast guard vessel with all aboard dead by suffocation ... the dreaded ocean phart is suspected once again in the area known as the Gore Triangle.

[P-40]

Be a good thing to keep that CO2 away from the plants. Might make them sick... :)

[keithtoo]

It is amazing how CO2 is described as a pollutant is most articles. No mention about how, without CO2, life would cease to exist. Jeez.

[theBuckwheat]

Ocean sediments already store an enormous amount of methane in the form of methane hydrates.

[Solamente]

I must be retarded.

Can't we solve this by planting more vegetation, which uses CO2 to create oxygen?

[theBuckwheat]

I am sure that it is just an inadvertent omission, but the carbon dioxide that everyone is expressing concern for came from the atmosphere. We are just being warned that it is dangerous to release it back to its natural point of origin.

[hawkaw]

Question

I think in the making of cement, CO2 is released when the limestone (calcium carbonate) bedrock is mixed with the other materials.

Am I wrong?

[nomorelurker]

I saw at least one proposal to take crop or other carbon type residues encase them in glass and drop them in the deep ocean as one solution.

[Bones75]

Also, where, pray tell, is the energy to pump millions of cubic meters of CO2 miles down into the deep sea floor going to come from?

Power plants? ..which burn fuel and release CO2 which will then also have to be pumped miles down into the deep sea floor?

[kinoxi]

Vegetation creates methane plumes over the Amazon rain forest which is supposedly more insulating than CO2. There is no way out of this leftist pseudo scientific mess.

[muawiyah]

We already have massive ocean currents that pull warm surface water down to the seafloor and pump it toward the other pole.

Best way to make use of them is to allow the surface water to absorb CO2. Once the currents drag the highly carbonated water to the seafloor, they will then be absorbed.

[Yo-Yo]

Water Vapor Rules the Greenhouse System

Just how much of the "Greenhouse Effect" is caused by human activity?

It is about 0.28%, if water vapor is taken into account-- about 5.53%, if not.

This point is so crucial to the debate over global warming that how water vapor is or isn't factored into an analysis of Earth's greenhouse gases makes the difference between describing a significant human contribution to the greenhouse effect, or a negligible one.

Water vapor constitutes Earth's most significant greenhouse gas, accounting for about 95% of Earth's greenhouse effect (4). Interestingly, many "facts and figures' regarding global warming completely ignore the powerful effects of water vapor in the greenhouse system, carelessly (perhaps, deliberately) overstating human impacts as much as 20-fold.

[Dan(9698)]

I think in the making of cement, CO2 is released when the limestone (calcium carbonate) bedrock is mixed with the other materials.

When limestone is burned, it turns to synthetic trona. That is calcium carbonate as it is used in glass manufacture.

If volcanoes didn't melt and spew gasses from the bedrock, there would soon be no atmosphere. They recycle the Carbon in the form of CO2, and also Oxygen in the CO2.

That is where the martian atmosphere went. It is bound up in the rocks because there are no more volcanoes to recycle it.

[Mike Darancette]

Injecting carbon dioxide into seafloor sediments rather than squirting it directly into the ocean traps the gas, minimizing damage to marine life while ensuring that the gas will not eventually escape to the atmosphere via the mixing action of ocean currents.

Are sea floors permanent? I thought that the sea floors eventually subducted under the continental plates? When that liquid CO2 in the seafloor sediments is heated then what? Geologically speaking very little is permanent.

[sox_the_cat]

It's lovely theory to sequester CO2 below the ocean, but it's already been mentioned the energy and cost to create a transport system to get it there must be extraordinary. Also, capturing CO2 can be done pretty well, but the daily volume output of CO2 from a single power plant is huge. The task of transporting that seems quite daunting.

[Larry Lucido]

Actually, I think earth's atmosphere can safely store "man made" carbon dioxide.

[Uncledave]

Renewable Energy Ping

Please Freep Mail me if you'd like on/off

[cogitator]

Can't we solve this by planting more vegetation, which uses CO2 to create oxygen?

There's a limit to the arable land that could provide a place for the vegetation and the amount that the vegetation could absorb.

[cogitator]

I think in the making of cement, CO2 is released when the limestone (calcium carbonate) bedrock is mixed with the other materials.

Yes. After fossil fuel burning for energy production, cement production is the second-largest anthropogenic source of CO2 to the atmosphere (about 1/3 of fossil fuel emissions).

[cogitator]

We are just being warned that it is dangerous to release it back to its natural point of origin.

We're being warned that releasing it very rapidly from organic carbon storage may have effects on the global climate.

[Paradox]

Sounds like one of the potential weapons in our arsenal, if and when we decide to manage this problem. Technology has brought us this problem, technology can get us out of it.

[cogitator]

This point is so crucial to the debate over global warming that how water vapor is or isn't factored into an analysis of Earth's greenhouse gases makes the difference between describing a significant human contribution to the greenhouse effect, or a negligible one.

Positive water vapor feedback essentially doubles the expected warming over the warming that would be due to increasing CO2 concentration alone. This basic view omits the uncertainties in cloud feedback effects, which are still large and which could add either a positive or negative feedback factor.

[cogitator]

Are sea floors permanent? I thought that the sea floors eventually subducted under the continental plates? When that liquid CO2 in the seafloor sediments is heated then what? Geologically speaking very little is permanent.

The time-scale for subduction and re-release is so long that we humans existing now, and 10 generations in the future, have nothing to worry about.

[cogitator]

Sounds like one of the potential weapons in our arsenal, if and when we decide to manage this problem. Technology has brought us this problem, technology can get us out of it.

I agree. If the cost-benefit analysis indicates that it costs the world more to have the CO2 in the atmosphere than to sequester it, then sequestration projects could be initiated. There are still too many uncertainties to commit to this idea now, but feasibility studies and technical analysis of how to do it might be useful when and if sequestration is deemed useful.

[kidd]

Deep-Sea Sediments Could Safely Store Man-Made Carbon Dioxide

So could shallow ground level trees.

[theBuckwheat]

>>
We're being warned that releasing it very rapidly from organic carbon storage may have effects on the global climate.
<<


I have not heard a single expression like this, but that does not surprise me, for "Global Warming" is not about climate at all. It is about ideology and power over free peoples.

There seems to be no concern about what might happen to the climate in any detail, except it will certainly be bad and we might ALL DIE!. But, more important than anything, we must rush to spend trillions of dollars on all these proposed "solutions" that are really unproven, and we must agree to all these restrictions on liberty and national sovereignty.

For example, we must agree to allow the UN to set up a body that will have the power (as ceded to it by the US and other nations) to issue permission for nations to consume hydrocarbons, which could lead to the UN exercising veto over our military during any future deployment.

Of course, just like Kyoto, some nations will be given a pass, such as India and China right now, and it will be just fine for Canada to pledge reductions in CO2, but to miss their target by a mile, but of course any target the US sets must be achieved or else!

But the real issue for science is 1) is the climate really changing in a way that is harmful to humans; 2) to what extent is man responsible for that change; and 3) what human behavior must we change to mitigate that change so it is no longer harmful to humanity.

[mo]

IMHO...there's something fishy about all this :)...its the anatomy of another scam..with the scammers trying to scam the american public and the Feds.....

[MrEdd]

Have they figured out how man made CO2 is heating up the other planets in our solar system, as well as the earth yet?

[kinoxi]

Our Sun has nothing to do with it of course. The Bush's keep the earth warm now...

[kinoxi]

The melting polar icecaps on Mars and all...

[bobdsmith]

The graph is wrong in two critical ways. First the contribution of water vapor is not that high. Second The natural/man-made ratio of co2 is not that high.

[Larry Lucido]

That is where the martian atmosphere went. It is bound up in the rocks because there are no more volcanoes to recycle it.

I didn't know that about mars atmosphere. I thought it "went" into outer space for some reason (blew away?). I know there is more potential atmosphere in the rocks but how would it have gotten there from above the surface?

[ClaireSolt]

I am for the Arbor Day solution. Round up all the enviornmentalists and snd them to the Middle east and North Africa to plant trees and groundcover.

[Larry Lucido]

Emissions from lunar rovers?

[bert]

Does you post mean to say....'its coke's fault"

[bert]

Do you mean making portland cement or concrete?

[RightWhale]

Well, that's easy. Just collect the excess CO2 and put it into a pipeline going three miles down and fifty miles horizontal into a set of six thousand injection wells under 10,000 atm pressure. Do this at 10,000 points all over the earth. Cost should not exceed $10 trillion construction plus $100 billion a year operations.

[keithtoo]

I think there may be a Halliburton/Cheney connection to the global warming on Mars.

[preacher]

Maybe saomeone will figure a way to store water vapor at the bottom of the ocean. It makes about as much sense.

[Dan(9698)]

I know there is more potential atmosphere in the rocks but how would it have gotten there from above the surface?

There was liquid water at one time, also the reason it is red is oxygen combining with the iron that is in the rocks.

There are areas in Wyoming that have red cliffs that are sandstone which oxidized as the sand was washed down and deposited. Without volcanoes to melt and separate the rocks into gasses, that oxygen is forever trapped.

Granted, the rock cliffs in Wyoming aren't melted too often, but on the edges of the plates, the sea floor dips under the other plate, and is melted and blown out through volcanoes.

Have you heard of the Yellowstone Caldera? We are overdue for it to erupt again, and so can expect a lot of recycling to happen in the future.

[cogitator]

So could shallow ground level trees.

But not as much.

[TYVets]

junk scientists need a federal grant PING

[cogitator]

But the real issue for science is 1) is the climate really changing in a way that is harmful to humans; 2) to what extent is man responsible for that change; and 3) what human behavior must we change to mitigate that change so it is no longer harmful to humanity.

Excellent summary. The next IPCC report will certainly address these points.

[Mike Darancette]

To get rid of the CO2 we need more Bushs.

[Solamente]

For a long time, I've had a probably un-doable vision of, for example, desalinating ocean water and slowly but surely creating a water table in the deserts of the world.

Then the vision gets crazier. Scoop the sand off the top of those deserts, and turn it to glass building blocks - some solid, some with conduits for the transmission and transportation of all our utilities. There would most certainly be vast treasures of human history unearthed in the bargain beneath those sands.

[P-40]

There was liquid water at one time

I always assumed that without plants developing to pull the moisture out of the soil so it could go into the air and form rain and on and on...Mars just sort of wound down and all the water went underground and the surface pressure just dropped to nothing. A few hundred nukes at the Martian polar ice caps followed up with a seeding program would test that theory...but I don't think it is going to happen. :)

[P-40]

But not as much.

Cutting down the forests to make way for new trees to store CO2 might work if the cut trees were kept from decaying. I'll see if the Sierra Club will take up the cause. :)

[Energy_Guy]

Dude - here’s how to understand CO2 as a “pollutant”

“Too much of a good thing”, eh?

Atmospheric concentrations of CO2 have gone from a historic 120-280 ppm (over the last million years or so at least), up to over 380ppm and we’re adding several ppm per year now as we speak. Oceans are releasing “stored” CO2 as their temperatures rise, adding several more ppm per year. Projections (reasonable ones) put us between 700 - 1100 ppm by 2100.

Guess what?!? Plants will love it, if there are many left, BUT OSHA puts 1000 ppm as an unhealthy limit on indoor air concentrations. What are we going to do when ALL the air is at 1000 ppm or higher?

This does not even count the climatic effects that the extra CO2 will have, and that we are already beginning to experience.

Think 21st century energy technologies, and consider that maybe the 19th century ones have outlived their usefulness and have become downright dangerous...