Sen. Robert Byrd from the coal state of West Virginia has long been seen as a pretty rock solid ‘no’ vote on the climate bill. Nate Silver’s “Probability of Yes” vote for Byrd is 19.4%, and I’ve heard that’s optimistic. He said this summer he wouldn’t vote for the House bill “in its present form” — although, like most Senators, he probably doesn’t know what in it.
Still, he has decided to engage in the process of working with other Democratic senators to push carbon capture and storage technology. His office press release quotes him saying:
“If our nation is to benefit from the next generation of clean coal technology, the private sector needs greater certainty and robust financial support in order to make the necessary investments….
I will continue to engage the Administration and the Senate to make sure that West Virginians have a seat at the table during this climate debate.”
E&E News PM (subs. req’d) had a big story on this Friday night, with details on the proposal:
Five influential coal-state Senate Democrats floated today they say would help with the widespread commercial deployment of carbon capture and sequestration technologies.
Sens. Robert Byrd of West Virginia, Max Baucus of Montana, Mark Warner of Virginia, and Arlen Specter and Bob Casey of Pennsylvania stand out among a group of eight Democrats calling on the Environment and Public Works and Finance committees to include a range of special incentives for the electric utility and coal industries in cap-and-trade legislation this fall.
They requested several changes to the House-passed climate bill, H.R. 2454, including more funding and bonus allowances to power companies as they face greenhouse gas emission limits on their new and existing plants. That would essentially allow power plant owners to collect more money in allowances as they sequester more emissions.
You can read the proposal here, but I wouldn’t bother because it’s pretty okay and certain to change more than once as this process evolves. It throws even more money at coal with carbon capture and storage, which I suspect is relatively pointless (see “Is coal with carbon capture and storage a core climate solution?“) And I doubt the money will even get spent because CCS is just too damn expensive (see Harvard stunner: “Realistic” first-generation CCS costs a whopping $150 per ton of CO2 — 20 cents per kWh!)
But I could be wrong, and it’s early well worth finding out if CCS works. That’s especially true since if it does, the future is cofiring coal and biomass with CCS and producing negative-carbon electricity. If more money for CCS gets Byrd’s vote — at least to block a filibuster — and the votes of people like Baucus, it’s well worth it. True, he might well bail on the final bill, but engaging him in the process seems like a positive step.
The biggest flaw in the proposal seems to be that gives too much money upfront to new coal plants that promise to do CCS, but then has no penalties if they fail to deliver on the CCS. That needs to be fixed, but I can’t see many scenarios where new coal plants without CCS get built after this bill passes. And the only CCS plants that get built will be ones that the government essentially covers most of the cost of, which means not bloody many until costs drop sharply, probably post-2030.
Here are more excerpts from the story:
Separately, the group suggested an exemption from new greenhouse gas technology standards on coal mines and landfill methane projects. Instead, they asked for both to be added to the list of domestic offset projects that industry could fund as an alternative to making their own direct emission reductions.
A Senate Democratic aide said this change could result in expanding the domestic offset pool by as much as 45 percent.
Without going into specifics, the group also urged the Senate to include language that addresses the legal liability for long-term carbon storage. And it encouraged the establishment of a $10 billion, 10-year program that would help get carbon capture and sequestration (CCS) technology into widespread use around the country — something that already is in the House-passed bill.
The senators also want to include a congressional finding that “it is in the public interest to achieve widespread, commercial-scale deployment of carbon capture and storage, both in America and throughout Asia before January 1, 2030.”
The draft language is the result of a working group led by Sen. Tom Carper (D-Del.) established in April as part of a broader outreach campaign to senators who do not sit directly on the relevant committees writing the climate bill. Sens. Amy Klobuchar (D-Minn.) and Joe Lieberman (I-Conn.) also signed onto the draft language.
“We believe our nation needs all sources of energy — including coal — to meet our future demands,” the group wrote to EPW Chairwoman Barbara Boxer (D-Calif.). “We also know that other countries, such as China and India, depend heavily on coal as an energy resource. Therefore, widespread, commercial-scale deployment of carbon capture and sequestration technology for coal will be critical if we are to meet our national and global climate goals.”
The senators said it is “imperative” that their legislative suggestions make it into the final climate change bill, though none of them promised that these requests alone would win their vote. Each said they have “other priorities” as the Senate forges ahead with its sweeping energy and global warming package….
“We’re very encouraged to see such a diverse group of senators working together, making progress, and moving climate legislation forward,” said Tony Kreindler, a spokesman at the Environmental Defense Fund.
“It is a good-faith effort to address the legal and regulatory barriers to widespread deployment of CCS,” added Paul Bledsoe of the National Commission on Energy Policy,
RSS
Subscribe by Email
Follow Climate Progress on Twitter
If we all clap for Tinkerbell REALLY hard, all that nasty CO2 will be held underground forever where it won’t contaminate our aquifers, leak and kill people, or raise electricity rates. Oh, and all that other stuff about coal mining will get fixed. And you’ll get a pony.
This is good, IMO.
Coal fired power plants with CCS, converted to biomass or biochar fuel, could be the nucleus of a massive carbon negative CO2 remediation scheme, which could potentially put billions of tons of carbon per year back underground, if applied worldwide.
Most coal fired power plants are located on rivers, which constitute a natural biomass/biochar collection and transport network, to bring biomass or biochar produced on the watershed that the river drains to the power plants. Biomass plantations could also be constructed upstream of the coal fired power plants, and the biomass or biochar floated down to the power plants on barges.
To get an idea of where the coal fired power plants are, download a database of power plants from the CARMA (Carbon Monitoring for Action) website, and import it into Google Earth. You can then cruise around in Google Earth, and see the power plants and where they are located.
Notice how many of the power plants are in the Mississippi basin. Notice the concentration of coal fired power plants along the Ohio river. Zoom in, and notice how many of the coal fired power plants have coal barges tied up on their river loading docks.
The cost of CCS depends on whether the efficiency of the power plants is enhanced at the same time.
Oxyfuel combustion simultaneously aids in CCS, potentially increases combustion temperatures, and aids in heat transfer. For these reasons, coal fired power plants can apparently seamlessly be adapted to oxyfuel combustion.
Another thing that can be done to existing power plants is to add an Indirectly Fired Combined Cycle (IFCC, aka. HIPPS) topping cycle. This adds a conventional gas turbine to the power plant, and runs it off heated air, then uses the output from the gas turbine to run the conventional steam cycle. Electrical output is greatly enhanced – enough to pay for the parasitic losses from generation of oxygen for combustion, and compression of the resulting nearly pure stream of CO2 for deep injection.
We need to seize every coal fired power plant in the U.S., and massively convert them to biomass or biochar fuel, oxyfuel combustion, an IFCC topping cycle, and deep injection of the resulting CO2 into deep saline, a couple of kilometers deep in the earth, which also lie under most existing coal fired power plants.
On edit-
That should be “deep saline aquifers”, in the last sentence of the above post.
The last time someone explained this to me (and VERY few people actually understand it), it was so complex and contrived and full of risk that it only made me wonder: what in the heck are we thinking about?
And I have a very good chemical engineering and science background and have worked in research in the oil industry, with complex refinery processes — which aren’t nearly as complex or contrived as this notion.
I doubt (very much) that Senator Byrd can even begin to explain what is involved here, really, in any way that shows that he “gets” it AND appreciates the complexity and risk.
And, keep in mind the volumes involved. Because carbon is the central ingredient in coal, the volume of “stuff” that would (presumably) have to be stored is HUGE. Let’s look at some stats. For every ton of coal going into a plant, how much mass would have to be stored? It’s HUGE.
We shouldn’t adopt this path or rely on it until every single politician who favors it can explain it, “appreciate it”, comprehend the risks, and explain why this is the best way forward, relative to other much simper clean-and-renewable energy approaches. Good luck.
Be Well,
Jeff
It would seam to me that establishing a retirement, retraining , relocation fund for displaced workers would be a much less expensive option than forcing compliance on the coal industry.
It’s a crying shame that every coal state Senator has to be pacified like this to keep them from supporting a filibuster. Can these people not put the national interest ahead of their own state’s?
“That’s especially true since if it does, the future is cofiring coal and biomass with CCS and producing negative-carbon electricity.”
That is never going to happen, nor should it ever happen. In addition to the C storage space issues mentioned by Jeff, there are a hornet’s next of ecological and economic issues with biomass-based energy, as the ethanol boom has shown, not to mention the many other problems with coal extraction and combustion. These include landscape destruction, acid rain and localized air pollution. And who is going to guarantee that the sequestered carbon stays buried, or knows how or where to bury it in the first place, or how much it will cost if it’s technically possible?
Coal burning with CCS is in the absolute last place as a solution to the energy and climate problems we face. Dead last, without even a close competitor.
Byrd’s reasoning: because West Virginia is now economically dependent on removing mountaintops, filling streams, and emitting greenhouse gases, we should find a way for it to remain economically dependent on removing mountaintops, and filling streams, without emitting greenhouse gases.
If the same reasoning had been used 100 years ago, we would still be heating our houses with coal stoves, and coal miners would still be loading sixteen tons and getting deeper in debt each day.
Oh, and mercury poisoning, let’s not forget that little inconvenience.
Something that ought to occur to any thinking person several times daily while dealing with US politics, yet I rarely see it mentioned: The US Constitution had some famous flaws that later amendments have gone a long way towards ameliorating, but still contains a basic one, originating in a dirty, anti-voter compromise and perpetuated by cravenness. All us voting animals are equal, natch, but the animals in small states are way, way more equal than others. Why should West Virginia, not to mention Wyoming, have as much strength in the Senate as NY and CA? No good reason. This natal flaw may well prove fatal, to the Republic and far beyond. There is no principled reason why this voting distortion is not just as bad as elections elsewhere we decry as stolen.
What would those member-by-member Senate projections look like if weighted by population?
Hi all-
Gaia is totally P.O.’ed and is coming after us with blood in her eye, so to speak.
She is doing her best Kali imitation, IMO, and doing a pretty good job of it, these days, no lie.
We don’t have that many opportunities to do the right things to turn this thing around, IMO, to not pay due attention to every option, and attempt to think in a purely logical, quantitative mode without preconceptions.
Humans tend to think by association, as the philosopher Hume pointed out hundreds of years ago. We associate good tasting food, which we have eaten in the past, with nourishment, for example, and most of us don’t understand why the food is good for us, we just eat it and get fat. So, for all of us, hidden conceptual frames are a problem.
The coal industry does not want to change, for example. And so they will tell us, or coal supported think tanks and academics will tell us, that CCS is too expensive, impractical, and will take many years to implement. They will do their level best to implant the “too expensive” frame, or the “too complex” frame, or whatever, in our heads.
The coal industry does not generally want “clean coal”, IMO. They want to do nothing, and convince the rest of us that they should be left alone. The problem is, we can’t really solve the runaway global warming/ methane catastrophe problem without them, IMO.
The current system, if left alone, will indeed take many years to transform itself to biomass/CCS, and my feeling about this problem, trying to visualize it in my head, as most of us are doing, is that we don’t have time to fool around begging the coal industry to do the right thing. So, we should seize the coal fired power plants, and convert each one, depending on its location, to natural gas, biomass/CCS, engineered geothermal, solar thermal, methane from hydrates plus CCS, nuclear, or whatever makes sense for that location.
We can’t solve this problem without putting billions of tons of carbon per year back in the ground, IMO. Are the quantities huge? You bet they are. But so is the problem. Long term, deep injection alone is probably not the answer. Long term, in situ mineral carbonation might be much better.
Guardian – Ocean floor could store century of US carbon emissions [basalt deposits below the ocean floor, actually - LP]
http://www.guardian.co.uk/ environment/ 2008/ jul/ 14/ carboncapturestorage.fossilfuels
Will CCS make a mess?
Maybe, although the 2007 IPCC report is relatively upbeat, about the potential for long term storage. Below 2.7 km, also, the CO2 becomes denser than water, and would tend to sink, rather than rise.
We might make a mess, but if we can turn the corner on runaway global heating leading to a probable methane catastrophe, at least we will be around to clean it up.
Dear Leland (Comment 10)
Leland, I understand that we have to address the climate and energy problems, of course. That’s why we are all here.
But, if I understand your comment, you are saying that coal folks don’t want CCS and, thus, they hold a view that it’s too expensive and complex.
I can assure you that I’m not in the coal industry and have nothing to do with it. Indeed, I’d close the coal plants asap (taking into account transition timing and also taking care for the employees, of course).
As a former chemical engineer, from Berkeley and with experience in the oil industry, I find the process incredibly complex, contrived, convoluted, and risky, all things considered. And that’s even before you compare it to the much simpler and more sane alternatives.
I know at least one other exceptionally bright scientist and engineer (with much more direct experience in relation to this) who feels the same way.
But — if you are saying that the coal folks themselves don’t even want to do it, that’s even MORE problematic. Given (in my view anyhow) that the process is incredibly complex, contrived, and risky, how does one take such a process and force people who DON’T want it to design and implement it well? It becomes an impossible task, in that case.
For example, if you ask me to do a super-duper triple-twist high dive, from one of those platforms, you have several problems. The dive is complex. I couldn’t do it even if I tried. And I don’t want to do it in the first place. It doesn’t sound like a good bet.
How about solar, wind, geothermal, and etc., complemented with the necessary transmission upgrades and (if people think it’s necessary, on a transition basis) natural gas?
Cheers,
Jeff
Very good sites for surficial in situ mineral carbonation include locations in Oman, Papua New Guinea, New Caledonia and northwestern Australia. There is even a bit in the wesern US.
At these more remote locations, air capture of carbon dioxide might be a good plan. I’m having some trouble determining even approximate costs.
NETL/DoE has been going full bore on characterizing underground sites near existing coal burners. Is not sponoring any air capture work as best as I can tell, only flue gas and so-called pre-combustion capture.
Hi Jeff-
Our main problem, the main culprit in global warming, IMO, is that the coal fired power plants are transferring something like 6-8 billion tons of carbon from the ground into the air, every year. If they could all be transformed into biomass/CCS plants, they could put this 6-8 billion tons of carbon back into the ground, and reverse this flow. Putting 6 billion tons of carbon back into the ground per year could put the 300 billion tons of carbon added to the atmosphere and oceans by the industrial revolution back underground in about 50 years. Transferring 6 billion tons of carbon per year back underground could also compensate for all other greenhouse gas producing industrial activities, and allow us to become slightly carbon negative societies.
http://en.wikipedia.org/ wiki/ Bio-energy_with_carbon_capture_and_storage
What I’m saying is that the coal fired power industry wants to be left alone, and is willing to do whatever lying they need to do to be left alone, generally. Many of them understand that CCS can be expensive, depending on the technical details. So, while they understand that the costs of CCS depend on the technical details, they are more than willing to exaggerate the costs and minimize the benefits of CCS in their lobbying and PR.
Historically, any time an industry is facing regulation, they mount an overt (lobbying, testimony before Congress) and covert (industry sponsored front groups, astroturfing, industry sponsored academic testimony) effort to exaggerate the costs and minimize the benefits of that regulation. The coal power industry is no exception, of course.
Ninety percent or so of the cost of CCS is due to the extra coal (or biomass or biochar) that would have to be burned over the lifetime of the plant. So, the real issue is efficiency.
Having an academic background, you undoubtedly understand Carnot efficiency. If we can increase the temperature of combustion, we can increase the efficiency of the power plant.
There are at least two “bolt on” technologies that can be added simultaneously to power plants to increase their efficiency. One of these is an IFCC topping cycle, which adds a conventional gas turbine, running off heated air at about 1200-1500 degrees C to the conventional steam cycle, which runs at 600 degrees C, or so. This increases the Carnot efficiency of the process. Another such technology is oxy-fuel combustion, which offers increased combustion temperatures, better heat transfer, and a nearly pure stream of CO2 for carbon storage, all without increased production of nitrogen oxides, at the cost of some energy for generating the oxygen from air and compressing the subsequent nearly pure stream of CO2 for deep injection.
Adding an IFCC topping cycle and oxy-fuel combustion to existing coal fired power plants could increase their Carnot efficiency and compensate for the parasitic efficiency losses caused by oxygen generation and CCS.
Deep injection of CO2 has been going on for years, for secondary recovery of oil, quietly, with few known side effects. New ideas such as using the Juan de Fuca plate off the Pacific Northwest for in situ mineral carbonation open the possibility of permanently sequestering enough carbon to undo the carbon poisoning of the biosphere caused by the industrial revolution.
Combining biomass or biochar fuel with CCS can have tremendous synergistic effects on the CO2 emissions problem, and regardless of complexity (not true, actually, it’s just combustion, not rocket science) and cost (which could be compensated for by increased efficiency), we’re going to have to do this in order to turn the corner on abrupt climate change, IMO.
Leland, there is no way to feasibly transfer the amounts of terrestrial carbon you are talking about to underground storage in 50 years without massive ecological, economic, and social disruption. As a limited contributor to the climate change problem, contributing to a slow draw down of atmospheric C over a long time span, maybe. As the primary mechanism, and quickly, no way. Terrestrial carbon sequestration, great, the more the better. Burn, capture and bury, no.
Hi Jim-
Actually, I don’t think this is true, fortunately.
Here’s a list of references that might change your mind.
Worldwide, carbon in standing biomass equals about 600 billion tons of carbon, about twice what has been released by fossil fuel combustion by the industrial revolution. Each year, about 60 billion tons of carbon from wildfires and decay are transferred from biomass to the atmosphere. The proposal is to divert about a tenth of this to biomass/CCS, worldwide.
http://en.wikipedia.org/wiki/Carbon_cycle
Oak Ridge National Labs has located 1.2 billion tons of “waste” biomass available per year in the U.S, containing perhaps 300 million tons of available carbon, obtainable without much disruption at all. Note that this study was done under sustainable, not emergency conditions, and did not take into account biomass plantations and river transport of biomass:
http://feedstockreview.ornl.gov/pdf/billion_ton_vision.pdf
The beetle killed trees in the West and Canada contain huge amounts of standing biomass, equal to at least a billion cubic meters of dead wood:
http://www.biocap.ca/rif/report/Kumar_A.pdf
The news about CCS is actually quite positive, not that you would know it listening to the coal power industry or the press.
Gotta go back to work, more on CCS later.
Leland, I’m not sure exactly what you have in mind, but I appreciate your optimism, and as I say it could be a long-term contributor, and I will try to look at your references. A few points though:
1. Putting 6 billion tons of C/yr into the earth will not draw down the anthropogenic-to-date component in 50 years, because a good chunk of that will be coming from coal burning. I don’t think the coal industry’s going to develop and install CCS and then not use it to burn coal, do you?
2. All terrestrial carbon, including that which burns, and that which decays, serves some (many) ecological purpose(s) during its C source time. Standing dead trees are wildlife habitat, erosion reducers, and partial shade for tree regeneration. Decaying vegetation serves all manner of critical functions, including supporting the food chain and radically altering the ground level micro-climate, in turn directly affecting soil respiration. These ecosystem services all need to be considered.
3. Fire. Generally speaking, C losses due to fire are only likely to increase, because fire suppression capabilities are already generally maximized, due to economic constraints. With climate change and fire suppression continuing, the chances of reducing fire’s effects is small, and only temporary if successful anyway, because fire hazard/risk increases with fire suppression. No mean feet to divert biomass that would have burned in wildfire, into bioenergy stock. Huge issues here.
4. Crop-based bioenergy has direct effects on food prices and soil carbon pools, depending on its intensity and mgt practices.
5. Only that biomass which is already being removed from its place of origin and not being used for some ecological or agricultural purpose is really eligible for what you’re talking about with some sort of negative side effect.
Like many geo-engineering schemes, there’s far, far, far more to these ideas than is apparent from a distance.
Let’s use the biosphere to increase carbon stocks above-ground like it’s done for hundreds of millions of years now, and reap the MANY benefits that this provides, rather than trying to burn and bury it just because we (maybe) can.
Hi Jim-
Thanks for the feedback. Taking your points in order:
1) I think there are two main ways to keep the coal fired power plants from burning coal, and keep them burning biomass or biochar. The first would be an honest system of carbon credits, that would reward carbon negative energy schemes for all of the synergistic benefits that would accrue from those schemes. Carbon negative energy schemes simultaneously put carbon back underground, displace fossil fuel use, minimize wildfire risk, minimize methane producing decay of biomass, and generate useful electricity which itself can be used for purposes, such as electric vehicles, that further decrease fossil fuel use. Carbon negative schemes should get something like triple the credits of schemes that just displace fossil fuel use, I think.
The second way of keeping coal fired power plants from burning coal is to nationalize them and convert them by force. This is the route I favor, actually, and it’s not as inconceivable as it sounds. We just took over big shares in GM and Citigroup, for example, and the sky has yet to fall in. GM actually seems to be doing better, I think, and with the Chevy Volt, might soon enter the plug in hybrid market in a big way. I think we might have to nationalize the coal fired power plants, just to find out what’s technologically possible, and prevent industry spinning, lying and stalling.
2) We do have to protect ecosystems, but the forests are going to burn anyway if we do nothing, and release a good chunk of that 600 billion tons of standing biomass into the atmosphere by 2100, according to increasingly dire modeling results. Yes, we need to minimize forest impact, and respect natural forest processes. But if we have to sacrifice some soil fertility, for example, to turn the corner on a developing methane catastrophe, it’s worth it. But I think it’s possible to play a win-win game with the forests, and use our intelligence to harvest carbon from them while massively replanting and reforesting areas all around the world.
3) Fire. Fire suppression, replanting, and biomass harvesting could be done synergistically, IMO. Fire budgets are strained, because nobody much is making a profit fighting the fires. But biomass is a valuable crop, and could help pay for forest management and fire suppression, while at the same time clearing fire breaks and fire roads through the forest, removing excessive undergrowth, and so on. There are new types of forest harvesting prototype vehicles, developed in Finland by PlusTech Oy, a division of John Deere, that actually walk through the forests like giant six legged spiders harvesting wood, minimizing forest damage and capable of operating in steep terrain:
http://video.google.com/ videoplay?docid=-6273379084715476228#
4) Crop based bioenergy competing with agricultural crops is a problem. Trees don’t necessarily compete with cropland, though. And there are 24 million acres of tree farms already in the American Tree Farm system, which certifies forests which are tree farmed in a sustainable manner. Some tree farmer families are on their third or fourth crop of timber from their forests, with no sign of ecological damage. In some of these forests, controlled burning during the wet seasons is producing much more open, fire resistant forests than unmanaged ones:
http://en.wikipedia.org/ wiki/ American_Tree_Farm_System
5) Not really true, IMO. With forests, and to a certain extent with agriculture, it is possible to have your cake and eat it, too. Ash from biomass combustion can be returned to the soil, for example. Deforested areas can be reforested, especially if this is paid for by carbon credits. Young forests sequester carbon more quickly than old growth forests, for example, and some biochar could be produced on site and returned to the soil, by controlled burning in the winter.
The objections to carbon negative energy schemes lack a desperately needed sense of urgency, IMO. If we don’t turn this runaway global warming leading almost inevitably to a methane catastrophe around very soon, it will likely be too late. It won’t be too many years in the future, when the 6 billion tons of carbon put back underground would be insufficient to stop the ecological meltdown we are seeing, right now. Momentum is building, right now, and it might already be too late. But we can’t control the past, only try to do better in the future, and hope.
Yes, it will be difficult to harvest sufficient biomass to run the scheme without severe ecological damage. But it is not impossible to do so, IMO. We have all of the scientific and technological tools necessary to create a successful carbon negative energy system, IMO.
The cost of creating a carbon negative biomass/CCS power system might actually be negative- it’s quite possible that electricity from enhanced efficiency carbon negative power plants could actually be cheaper than that from coal fired power plants. Certainly, biomass is roughly as cheap as coal, rivers constitute a natural biomass transport network, and there are huge potential efficiency gains possible from transforming the coal fired power plants. Not to mention the value of carbon credits, which could be very substantial, especially if the synergistic effects of carbon negative energy schemes are rewarded proportional to their contribution to solving the problem.
Hi All-
Here are some CCS links that offer the potential to chemically transform to carbonates or store large amounts (hundreds of billions of tons) of CO2:
Carbon Dioxide Sequestration in Deep Sea Basalt:
http://www.pnas.org/ content/ 105/ 29/ 9920.full.pdf+html
Here’s a link to the Kansas State University NatCarb database and interactive map of deep saline aquifers, which contain sufficient storage space for a few trillion tons of CO2:
http://geoportal.kgs.ku.edu/natcarb/atlas08/gsinks.cfm
In the supporting downloadable files, they claim to have located between 3 and 12 trillion tons of CO2 storage potential in the deep saline aquifers under North America.
Here’s a promising way to potentially create runaway, positive feedback CO2 mineral carbonation in mafic rocks:
In Situ Carbonation of Peridotite for CO2 Sestration:
http://www.pnas.org/ content/ 105/ 45/ 17295.full.pdf+html
Finally, here are results from NETL of the existing large scale Weyburn and Sleipner CO2 deep injection projects, which show no sign of leakage from deep injection, so far:
http://www.netl.doe.gov/ technologies/ carbon_seq/ refshelf/ project%20portfolio/ 2009/ General/ Commercial-Scale%20Tests%20Demonstrate%20Secure%20CO2%20Storage%20in%20Und.pdf