Global warming 'cure' found by scientists

[OKIsItJustMe]

http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2007/11/07/eawarming107.xml

Global warming 'cure' found by scientists

By Charles Clover, Environment Editor
Last Updated: 5:01pm GMT 07/11/2007

A "technical fix" that could stop global warming by taking billions of tons of carbon dioxide out of the atmosphere and save the coral reefs from being destroyed by acidification has been developed by scientists.

The process could be used on an industrial scale to remove excess carbon dioxide caused by the burning of fossil fuels from the atmosphere in "a matter of decades rather than millennia," according to researchers from Harvard and Penn State universities.

The process relies on speeding up a process that happens naturally, whereby carbon dioxide dissolved in sea water breaks down volcanic rock and soils to make alkaline carbonic salts.

The water flows into the ocean and increases its alkalinity. Sea water containing more alkali can absorb more carbon, so more carbon from the atmosphere is "locked up" and becomes harmless bottom sediments, according to the journal Environmental Science and Technology.

Researchers estimate that it would take a cube of volcanic rock 10 kilometres across to return the concentration of carbon dioxide in the Earth's atmosphere to pre-industrial levels.

Unlike other proposed "technical fixes" that "sequester" carbon dioxide from the atmosphere, this one makes the sea more alkaline and therefore counteracts the other side effect of more carbon dioxide entering the atmosphere - the acidification of the sea.

...

"The local effect would be alkali pollution of the sea - but we are polluting the sea globally by putting carbon dioxide into the ocean. This method is expensive and therefore it's not the first line of attack for the global warming problem.

"The first is energy conservation, the second the substitution of fossil fuels with solar energy or biofuels, and the third - and above dissolving rock into the sea - comes carbon capture and storage from power plants. We know what technology is needed for that and engineering companies can do it."

Prof Watson, an expert on the carbon cycle and the oceans, said that dissolving rock was "worth considering" if the world got into a situation in which the oceans were dying because of acidity and we needed to alleviate the problem. "If you did it the right way you might be able to save the coral reefs from the worst effects. I would see it being done in areas where there may be another reason for doing it as well, such as this.

"There is no single 'silver bullet' for global warming."

Other "technical fixes" for global warming have concentrated on seeding the oceans with iron filings or nitrogen to stimulate algal growth in the hope that this would then die and take the carbon the plankton contained to the sea bed.

[mike_c]

1. as an ecologist, I applaud this sort of thinking, but I'm a bit sceptical...

...about conducting experiments in planetary engineering on THIS planet at the moment....

[TheWraith]

14. Well, it's the only one we've got.

So if we’re going to try this sort of thing, we’re going to have to try it at home.

Obviously 1000 CKM of volcanic rock is vastly more than we can find and process at the moment, but this might be a useful process to undertake. And it’s not like we have to turn the clock back to the beginning of the industrial revolution--returning the levels of ten years ago would be a good start. I’d start with small scale tests, to make sure everything works as advertised.

Speaking of planetary engineering, I remember many years ago reading an article about some university students who’d designed a way to plant trees using self-burying, degradable capsules dropped from Air Force B-52 bombers. They were talking about being able to plant 50,000 trees a day.

The catch was that given the speed the trees came down at, if there was anything in their way when they hit, it would be pulverized. Still, used in the right areas, it could be an effective fast reforestation technique.

[skids]

17. This will require years of planning by our best minds...

...it is the best idea I've seen proposed so far, but I am sure there will have to be a global consensus about how to go about it before anything gets done. For example the best source of the "pre-weathered rock" needs to be chosen so that any impurities in it are known to be unlikely to cause additional problems.

This is the only solution I have seen proposed that tackles ocean acidification, which is a problem in and of itself. If it only fixed ocean acidification and not climate change, even then it would still be worth consideration. Ocean acidification is a bad, bad thing.

Anyone interested in the chemistry involved here, see this article:

http://www.realclimate.org/index.php?p=169

[OKIsItJustMe]

2. Speeding up earth's natural climate control

http://pubs.acs.org/subscribe/journals/esthag-w/2007/nov/science/ee_mitigate.html

Science News – November 7, 2007

Speeding up earth's natural climate control

Could removing acid from seawater slow global warming?

As greenhouse gas levels rise faster, some scientists hope to drive the trend in the other direction by speeding up the planet's natural abilities to soak up CO2. A new study published in ES&T (DOI: 10.1021/es072039a) proposes a novel way to accelerate the ocean chemistry that absorbs CO2.



Oceans have absorbed about one-third of the CO2 that humans have produced so far, and if emissions ceased, the oceans would eventually take up all of it. But the process takes thousands of years, which is much too slow to keep up with the current CO2 rise, says Kurt House, a Harvard doctoral student and lead author of the new study.

"The more acidic the ocean is, the less CO2 it will hold," House explains. On the other hand, alkaline or basic solutions have a strong tendency to absorb CO2. Thus, a more alkaline ocean would pull more of the gas from the air.

Other ideas for increasing ocean CO2 uptake have focused on stimulating phytoplankton growth or increasing alkalinity directly. While House was jogging along the Charles River near Harvard one day, it struck him that he could instead remove acid to achieve the same effect. Eventually, he developed an approach called electrochemical weathering.

Weak acids in water normally dissolve rocks on land over time, forming an alkaline solution that runs into rivers and then the sea. Electrochemical weathering creates a stronger acid to drive much faster reactions. Still at a theoretical stage, the method involves passing an electric current through seawater to separate out chlorine and hydrogen gas, similar to the industrial chloralkali process used to make chlorine gas. The chlorine and hydrogen are then combined in fuel cells to form strong hydrochloric acid. The fuel cells would be housed in an industrial-scale plant that would collect and use the acid to dissolve silicate rocks, which are common worldwide. This would neutralize the acid and the resulting alkaline solution could then be returned to the sea. Overall, the process would help stabilize the oceans' pH, House says; oceans are currently becoming more acidic because of rising CO2 levels.

For profit, plants could sell carbon reduction credits in a cap-and-trade scheme. House says the process could potentially absorb 1 gigaton of CO2 annually. This would require building coastal processing plants equivalent in capacity to about 100 large sewage treatment plants, according to House and his coauthors, Michael Aziz and Daniel Schrag of Harvard University and House's brother Christopher House of Pennsylvania State University. That number of plants is "not a lot," says David Archer, an ocean chemist at the University of Chicago. Archer calls the approach "clever" and says that compared with planting more trees to take up CO2, "with this method you have dealt with CO2 in a more leakproof way."

The idea faces major hurdles. If put into practice today, it would cost at least $100 per ton of CO2 removed; more efficient electrolysis and fuel cells could reduce the cost. Electrochemical weathering also uses a lot of electricity; if coal is burned to generate that power, the whole process saves less CO2 than could have been reduced by replacing one coal-burning power plant with a plant run on carbon-free renewable energy. But in the best case, an electrochemical-weathering plant running on renewable energy could offset nearly twice as much CO2 compared with the reduction from replacing a coal plant. The team suggests tapping into geothermal energy, which is underused because geothermal supplies are often located far from cities with high electricity demand.

Another problem is localized pollution. "Around the plant you would get a very basic solution," which could contain chlorinated byproducts, House says. These byproducts could harm sea life locally.

Researchers Greg Rau of the Lawrence Livermore National Laboratory and Ken Caldeira of Stanford University's Carnegie Institution proposed another weathering process. Called accelerated limestone weathering, their method would capture CO2 from power plants to dissolve limestone, creating carbon-rich brine for ocean storage. Caldeira says the approach would use less energy than electrochemical weathering but would not capture airborne emissions. House's process "is on sound theoretical ground" but would likely be too expensive and inefficient to be practical unless it was run on cheap renewable energy, he says.

Nevertheless, Caldeira calls for research funding for a broad array of possible climate solutions in order "to get new ideas on the table." —ERIKA ENGELHAUPT

[phantom power]

3. A cube 10 km across == 1000 cubic kilometers.

Just to put that into perspective.

[XemaSab]

8. All we need is a repeat of the Lava Creek Tuff event

http://en.wikipedia.org/wiki/Lava_Creek_Tuff

/sarcasm

[Richard D]

9. That could work . . .

. . . and wiping out the western half of the US would probably reduce carbon emissions a lot as well.

[XemaSab]

10. Not as much as wiping out the Eastern US would

:popcorn:

[OKIsItJustMe]

11. Sure...

The magnitude of the problem is tremendous, taking us more than a century. I wouldn't expect the magnitude of a "fix" to be small.

To put things in a perspective for people (like me) who find a cubic kilometer hard to imagine, the 1980 eruption of Mount Saint Helens involved about 1.2 km³ of material.

[phantom power]

12. I'm willing to consider terraforming the earth.

From a benefit/risk matrix perspective, it may be a reasonable choice, given the direction we are currently headed.

I just wanted to throw the number out there, as another way to see the scale of the problem. Makes an average gravel quarry look pretty puny by comparison.

[pscot]

18. Hawaii (the big island) is made of volcanic rock

They wouldn't miss a few cubic kilometers of the stuff. The caustic by-product could be pumped directly into deep water where it could disipate with minimal effect. The Aleutians, Indonesia, the Philippines, Japan, the Azores, Iceland, the Falklands are all potential sites for such a facility. Together they offer millions of cubic kilometers of volcanic rock. I think it would be a good idea to build a plant, and see how it works. If we can afford 3 billions a month to perpetuate the slaughter in Iraq, surely we can spend a few dollars to secure our future on this planet.

[Richard D]

4. A cube of volcanic rock . . .

. . . 10 kilometers across. Whew. That's huge.

[EST]

5. Yeah, when you compare it to one dump truck...

even a really big one.

[The2ndWheel]

6. Son of a...

"The process relies on speeding up a process that happens naturally"

Just because it happens naturally, doesn't mean you can speed it up and everything will be alright. It happens a certain way, at the speed it does, because that's how the system evolved. If we start fucking with planetary stinkin' evolution, as with everything else that we've felt the self described right to fuck with, we'll end up making more problems. I don't know what they'll be, but that's why they're called unintended consequences. They're going to happen no matter what we do, be it live in caves, or transform the planet into a habitat built for a single species that is downloaded onto a supercomputer, but we've gone a certain way up to this point, and now we're having to deal with these consequences of our past actions. Is it really the right way to go to find some massively complex way to not have to pay the bill again? After you start running out on checks every time you eat, eventually you'll have to waste far more energy trying to get around whatever security has been set up to catch you than the meal is worth. There are no more restaurants. We've been to every one of them, at least once. We put on a fake mustache, plastic glasses with the big nose, maybe even a hat every now and then, but next we'll have to get a haircut and gain weight. Then lose the weight, grow the hair back, but give ourselves a bald spot. Then we have to grow an extra foot in height, grow an extra foot period, just so we can get some type of discount(which we won't pay for anyway). Then we have to cut the new foot off(both height and actual foot), have a sex change, learn a new language, and then have a blue crayon with us for some reason. It just gets crazier after that.

[Systematic Chaos]

7. We're not supposed to be laughing about this...

...are we?

Because your post made me laugh pretty hard.

[kestrel91316]

13. kestrel's version of the cure:

Grind up the volcanic rock real fine and sow it across the ocean surfaces. No large amounts in any one place, of course.

If the energy used to do this generates too much CO2, it would be a no-go. I'll let someone else do the calculations.......

[pscot]

15. Atmospheric CO2 is currently at about 380 ppm

According to evidence from ice cores, the norm for the last 400,000 years was 280ppm. Predictions are that CO2 will reach 450ppm by 2050. In other words, we are already off the charts and heading higher. There's a very tight correlation between temperature and CO2. Warming affects oceans and ice cover first. Air temperature lags slightly. We're committing ecological suicide. How can we talk seriously about solutions when we can't even apply the first law` of holes? I'll believe we mean business when James Inhofe gets down on his knees on the Capitol steps and apologizes to Al Gore.

[yop]

16. Aggregate

What if we used basalt instead of the stone we currently use? If we paved the world's roads with basalt, how much CO2 would that neutralize?