Among the many technological "fixes" that utilities are using to try to stave off global warming is "coal washing" to filter out impurities. Pictured here is a now-decommissioned coal washing facility located in Clay County, Eastern Kentucky.
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Dear EarthTalk: What are some of the leading proposed technological fixes for staving off global warming, and how feasible are they?
-- James Harris, Columbus, Ohio
While most of the world fixates on how to reduce the amount of carbon dioxide (CO2) and other greenhouse gases we emit into the atmosphere, scientists and engineers around the world are busy working on various “geo-engineering” technologies—many of which are highly theoretical—to mitigate global warming and its effects. Many scientists oppose using new technology to fix problems created by old technology, but others view it as a quick and relatively inexpensive way to solve humankind’s most vexing environmental problem.
One of the theories proposed for reducing global warming involves deflecting heat away from the Earth’s surface with solar shields or satellites with movable reflectors. Computer models suggest that blocking eight percent of the sun’s Earth-bound radiation would effectively counteract the warming effect of our CO2 pollution. The idea was inspired by the cooling effects of large volcanic eruptions—such as Mt. Pinatubo in 1991—that blast sulphate particles into the stratosphere. These particles reflect part of the sun’s radiation back into space, reducing the amount of heat that reaches the atmosphere.
Another technological fix involves “sequestration,” the storage of CO2 either deep underground or deep in the ocean. Some of the nation’s largest utilities, which are also “washing” coal to filter out impurities, are working on ways to capture the CO2 they emit and store it miles below the Earth’s surface. Costs of such technologies have been prohibitive, but new regulations could force the issue in the near term.
Another leading theory, “ocean fertilization,” entails scattering iron powder throughout the world’s seas, providing nutrients to boost the amount of phytoplankton that thrive in the water’s upper layers. Through photosynthesis, these plants absorb CO2, which in theory stays with them when they die and fall to the ocean floor. Initial experiments have not lived up to the hype, however, but more research is underway.
Yet another take on altering the seas for the sake of the climate, “engineered weathering,” entails replacing some of the oceans’ carbonic acid with hydrochloric acid. This, the theory goes, accelerates the underwater storage of CO2 otherwise destined for the atmosphere. According to Harvard Earth and Planetary Science Ph.D. Kurt Zenz House, engineered weathering “dramatically accelerates a cleaning process that nature herself uses for greenhouse gas accumulation.”
While the cost of many of these so-called “geo-engineering” fixes would not necessarily be prohibitive in light of the cost of transforming our global energy economy, the risks of unintended consequences weigh heavily on even the researchers proposing them. “Personally, as a citizen not a scientist, I don’t like geo-engineering because of the high environmental risk,” Ken Caldeira, a researcher at California’s Carnegie Institution of Washington, told New Scientist. “It’s toying with poorly understood complex systems.” But he also wonders: “Is it better to let the Greenland ice sheet collapse and let the polar bears drown their way to extinction, or to spray some sulphur particles in the stratosphere?”
CONTACTS: New Scientist, www.newscientist.com/article/dn11993; Science Daily, www.sciencedaily.com/releases/2007/11/071129132753.htm.
EarthTalk is produced by E/The Environmental Magazine. SEND YOUR ENVIRONMENTAL QUESTIONS TO: EarthTalk, P.O. Box 5098, Westport, CT 06881; earthtalk@emagazine.com. Read past columns at: www.emagazine.com/earthtalk/archives.php. EarthTalk is now a book! Details and ordering information at: www.emagazine.com/earthtalkbook.
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32 Comments
Add CommentEasy.
Reply | Report Abuse | Link to this1. Build big ship.
2. Put people in ship.
3. Send ship to moon.
3b. Or into the sun.
Carbon sequestration can be achieved by Pyrolysing Biomass. This can be done by having county-wide forests all around the world that produce hydrogen and biochar. Surprisingly the technique has been used for at least 2500 years in the amazon basin. It only requires small local charcoal ovens, specially adapted to capture the hydrogen. Investment of around $70k is require to produce several tons of charcoal per day capacity. With enough of these, Climate Change can be averted. See www.eprida.com
Reply | Report Abuse | Link to thisCoal washing does not have anything to do with reducing carbon dioxide emissions from coal, and is not part of the solution to climate change. It is a technique to reduce mineral content of coal so that it burns with less sulfur and nitrogen oxide emissions. This makes it easier for coal-fired power plant to meet National Ambient Air Quality standards. The coal washing station in the picture, which I have visited, is an old, out-of-date plant.
Reply | Report Abuse | Link to thisEco-steve is correct that biochar is a core geo-engineering solution to reducing emissions and sequestering carbon at the same time. It is a much more rational solution than any discussed in the article.
Reply | Report Abuse | Link to thisSo how many satellites would it take to block 8% of the sun's rays?
Reply | Report Abuse | Link to thisOur planet is an extremely complex system. We have been trying for years to fix problems using our ingenious ideas. Inevitably we cause some unexpected side effects that are usually the result of upsetting the existing balance. Our best computer models can not predict all possible result of changes we make. There are too many variables.
Reply | Report Abuse | Link to thisSequestering CO2 underground makes as much sence as trying to store water in a sieve. The earth's crust is not as solid as it seems, just go look at the mountains. See for yourself how horizontally deposited flat layers have been upended and twisted.
Don't burn coal! Let million year old sequestered carbons alone. Spend the money allocated to searching for and drilling into underground caverns to find hot rocks and generate geothermal energy.
A society of energy extravagant, greedy homo sapiens can not fix the greenhouse gas problem. Population is the main force driving green house gas emissions.
The solutions here are just plain silly. For instance, we get the energy from burning fossil fuels by releasing carbon, it would take more energy to sequester it than was produced in the first place. The best you could do would be to pump the smoke underground, perhaps into oil/gas pockets... but I doubt that will work. Eco-Steve was right to suggest biochar. The process takes care of itself, producing both energy and charcoal. Now, if the charcoal is burned, it won't help much. If it is mixed with the soil, then you increase the fertility of the soil and increase its carbon content effectively having the trees take on carbon, and then store it in the ground.
Reply | Report Abuse | Link to thisI would imagine this would work well as an at-home generator/heater system. You can use waste heat to help heat the home in the winter and/or the hot water during all times of the year.
There are really a few things we need to do, first we need to build more efficiently. It is possible to build a home that uses only 20% of the average energy consumed in the US. This mainly includes proper insulation, and passive solar and geothermal design. 40% of the energy consumed in the US is used to heat/cool homes. It is possible to completely eliminate that figure with proper construction practices (which don't cost anything extra).
Second, we need to produce our own power on site via solar and wind solutions. While these aren't that great at the moment, if you build your home right, you won't need a very big system.
Third, we need to switch from mostly driving cars for getting around, to mostly riding bicycles. For those who have long commutes, electric assist bicycles work really well. Cars are great for longer trips, or trips that include more than one person, or large cargo that can't fit on a bike rack.
I also think we should switch to composting toilets. This would reduce the amount of water the average household uses by half, produce useful compost for personal gardens/landscape, and relieve a lot of the burden on the water treatment facilities which will no longer have to worry about black water, only gray water.
It's a lot to change, but it would reduce quite a bit of the damage we're doing.
I agree with Sci earthling.. Carbon sequestration is just kicking the issue for the future generations to deal with. It makes no sense to bury CO2 more than it makes sense to bury all the garbage in the world..see WALL-E ;)
Reply | Report Abuse | Link to thisWhat REALLY makes sense is to transform our disposals in electricity or methane in order to power our cars, houses and cooking ovens. Then let the earth self-heal...CO2 resulting of that process is inherently captured and it can be used for what it is really needed. The resulting by-products of this process are (guess what)... fertilizers.. to grow more food.. CRAZY, ISN'T IT?
It is futile to talk about green WHATEVER if we continue to drive cars that burn THAT much gas and the CO2 industries supporting those cars emit.
Scientific earthling implies there are no solutions, then proposes geothermal energy. Every industry, including geo, has it's down side. It seems any 'new' idea is considered a "silver bullet", too dangerous to be pursued. Would we have said the same about solar, wind and geo energy if we were around when they were first being developed? Most technology starts small and we have plenty of time to consider the results. Any industry that's a burden in the short run, and a gain only in the long run, isn't likely to become addictive.
Reply | Report Abuse | Link to thisYes, charcoal sequestering is a fair idea. Charcoal is also a very good insulator, though delicate and needing fire retardant. But cutting trees to cook the wood and sequester also removes needed minerals from the forest soil. It maybe makes sense if the main purpose is home heating and maybe recovery of some organic chemicals which are distilled off. That used to be where we got methanol or "wood alcohol".
By the way, I favor sequestering CO2 on deep ocean floors, but only in special circumstances. Below 1 km depth, at normal ocean temperature, CO2 is liquid and heavier than water, so it easily stays in place in "CO2 lakes". A covering of plastic or something that floats on the CO2 but not on salt water would help to keep it from dissolving in the water. There is no life to be disturbed in deep oceans, except around volcanic vents.
Daniel35 the very best solution is a lower human population. Current population growth rates are unsustainable, especially if ever-single one of us desires the lifestyle of the rich and famous, which implies an energy extravagant society.
Reply | Report Abuse | Link to thisPopulation densities also affect our compassion. Societies living at higher densities have less compassion for their fellow humans. (Example: compare city folk to country folk)
Remember there is a carbon cycle. Tons of CO2 enters and leaves the environment every second. Animals live generating CO2 from the food they consume, plants use solar energy to convert CO2 into food primarily for themselves, animals eat plants/animals and gain access to stored solar energy.
Coal is million plus year old carbon. Coal has an active surface and binds gasses like methane, which are released when coal is mined. Burning coal is the also the principal source of mercury in our oceans and in our food chain. Our present predicament is a direct result of coal and oil being used to generate energy. Less than a third of the energy available from coal is converted into electricity.
I know we are addicted to energy. Geothermal using closed loop (my preference) heat recovery is financially competitive with coal. We only do things for financial reward, so I suggest it as an alternative to coal.
Sequestering CO2 as char is great, but it is sequestered for short period of time and returns. Burning coal is adding CO2 from the long-term cycle into the short term CO2 cycle.
I agree nothing is foolproof, no silver bullets. CO2 is soluble in water and ends up acidifying our oceans. I cannot see us pumping liquid CO2 into giant plastic bags and storing them at the bottom of the ocean. There is life everywhere on our planet, I am sure we shall find life forms at great depth in our oceans, we can't go there at the moment.
I totally agree with scientific earthling on population. Any other solution is temporary (though perhaps necessary in the interim). Many solutions being suggested wouldn't even keep up with present population growth. It starts with our animal instincts for greed, with too much success as a species, to the point where we think we're separate from the laws of nature. Since ultimately we "can't take it with us", we make lots of little copies of ourselves to pass it on. Over-population leads to faster spread of disease (maybe a good thing as negative feedback). It also leads to the need for central control, which unfortunately tends toward elitism capitalism, fascism and eventual collapse, as has happened many times in the past.
Reply | Report Abuse | Link to thisInstead of tax deductions, we need birth taxes, hopefully increasing exponentially with the number of births per mother. We need every kind of birth control available to all and encouraged. Replace "Be fruitful and multiply" with "Make love, not babies, and doublely reduce the causes of war." Encourage non-reproductive sexual relationships and behaviors. Extend "Right-to-Die" laws to everyone, and maybe encourage their use. Need I go on?
But is population control going to happen while we still have the possibility of controlling mechanisms that could end civilization, or perhaps all life on earth? Consider the scenario where as we run short of fossil fuels, we turn ever more to biomass, increasingly cutting our forests for fuel. We continue to adapt to climate change and strive for business as usual, ignoring more direct solar alternatives. As we run short of all fuels (carbon fuels as the basic source), necessarily reducing our numbers and CO2 emissions, methane clathrates (not very different from permafrost, but in large amounts under the oceans) suddenly start breaking down in a big way to release methane, a greenhouse gas (GHG) 22 times more powerful than CO2. As temperature rises, more water vapor (a GHG even more powerful) goes into the air, perhaps turning the Earth into another Venus. If anyone sees reasons this can't possibly happen, I'd certainly like to hear them. Civilization and humanity are a long way from perfect, but there are still some parts of them I'd like to save.
"Coal is million plus year old carbon. " Actually, the carbon's been somewhere here since the earth began, but organically solidified and deposited mostly many millions of years ago. Obviously burning coal is a main part of the climate change problem.
One problem with geothermal is that it's not easily available.
I totally agree with scientific earthling on population. Any other solution is temporary (though perhaps necessary in the interim).
Reply | Report Abuse | Link to thisMany solutions being suggested wouldn't even keep up with present population growth. It starts with our animal instincts for greed, with too much success as a species, to the point where we think we're separate from the laws of nature. Since ultimately we "can't take it with us", we make lots of little copies of ourselves to pass it on. Over-population leads to faster spread of disease (maybe a good thing as negative feedback). It also leads to the need for central control, which unfortunately tends toward elitism capitalism, fascism and eventual collapse, as has happened many times in the past.
Instead of tax deductions, we need birth taxes, hopefully increasing exponentially with the number of births per mother. We need every kind of birth control available to all and encouraged. Replace "Be fruitful and multiply" with "Make love, not babies, and doublely reduce the causes of war." Encourage non-reproductive sexual relationships and behaviors by all. Extend "Right-to-Die" laws extended to everyone, and maybe encourage their use. Need I go on?
But is population control going to happen while we still have the possibility of controlling mechanisms that could end civilization, or perhaps all life on earth? Consider the scenario where as we run short of fossil fuels, we turn ever more to biomass, increasingly cutting our forests for fuel. We continue to adapt to climate change and strive for business as usual, ignoring more direct solar alternatives. As we run short of all fuels (carbon fuels as the basic source), necessarily reducing our numbers and CO2 emissions, methane clathrates (not very different from permafrost, but in large amounts under the oceans) suddenly start breaking down in a big way to release methane, a greenhouse gas (GHG) 22 times more powerful than CO2. As temperature rises, more water vapor (a GHG even more powerful) goes into the air, perhaps turning the Earth into another Venus. If anyone sees reasons this can't possibly happen, I'd certainly like to hear them. Civilization and humanity are a long way from perfect, but there are still some parts of them I'd like to save.
Daniel35: You now see the world as I do. I am glad of that, but sadly after a lot of thought I have come to the conclusion we are doomed, mainly because we are not going to control our numbers.
Reply | Report Abuse | Link to thisMy evolution to this conclusion was similar to person being told that he/she was going to die in the near future. You go through several stages: Can't happen to me. Why me? Oh well!
Yes I would like to have a right to die law too.
Daniel35 : Biochar returns all mineral content to the soil when biochar is ploughed back in, only the hydrogen is burned (and a liitle carbon monoxide), producing, of course, water as 'waste product'.
Reply | Report Abuse | Link to thisScientific Earthling : Charcoal from man's first hearths still exists after 100,000 years, and can be dated by Carbon 14 methods.
Low-temperature Biochar also contains complex distillates and condensates whose exact effect on soil is being actively studied. But we know from ancient 2,500 year old amazonian biochar soils that they have an enhancing effect. Look up 'Terra Preta' on your search engines.
eco-steve:
Reply | Report Abuse | Link to thisFinding a small amount of old carbon does not mean the bulk of biochar remains sequestered. There are short, medium and long term carbon cycles. Most carbon is locked up as limestone on our planet, we release it when we make cement.
Are you aware C14 levels were increased 900% by nuclear testing during the 1950s. Think what it could be doing. It does eventually revert to nitrogen.
You talk about ploughing, I believe it is bad agricultural practice. Read Peter Andrews - Beyond the Brink -he is not a scientist and makes claims that termites generate huge quantities of CO2. No they generate about 15% of all naturally occurring methane(worse than CO2). However apart from such oddities, the book is an excellent interpretation of the natural environment as he has seen it and explains how he converted salt infested degraded agricultural properties into thriving agricultural properties.
These ideas are from his book: A farm's fertility is a result of organic matter in the soil. A farms green surface area is a measure of fertility being generated on the farm. Ploughing leaves fields free from plants for months shutting down the fertilisation process and at the same time carbon in the soil oxidises.
By producing this "bio Char" you have to heat it. This will produce CO2 and CO in the process.
Reply | Report Abuse | Link to thisTo sequester the Carbon that is the bio char, it has to be buried. This will have the result of cutting down forests and burying them. It will take necessary nutrients out of .
(The process you talk about being 25oo years old did not bury the char, but put it back into the soil for the plants to use. )
This process of CO2 sequestration will create more CO2, and make it harder for plants to take in CO2 to produce O2 and sugars. A very short sighted attempt to solve a problem that is actually more political than it is physical.
scientific earthling, I generally agree with you, especially about population reduction and control, the ultimate long term solution. But how many species are we going to lose before we get there? Anything we choose to do or not do on a global scale is the equivalent of that devil, geoengineering. Even hunting and gathering involves technology, and it would never stay at it's lowest level. Local innovations would never remain local. Instead, we have to learn to use our foresight, maybe the greatest advantage the human animal has, stay within the bounds of our viable environment and experiment with caution.
Reply | Report Abuse | Link to thisI think you're wrong on a couple of items.
As far as I know, char by itself doesn't burn if you keep flame away from it, and doesn't oxidize slowly. I don't know of any lifeform that can digest it until it's burned.
I think these days, occupied or at least remote-controlled submarines can go to the deepest areas of the ocean. Active life only exists where there's the possibility of energy exchange, such as in sunlight or near undersea volcanic vents.
No great technology would be needed to sequester CO2 on the deep ocean floors. If you pump it from the surface as a gas, it becomes liquid at temperature and pressure of less than 1 km depth, and compresses more to be heavier than seawater at about 1 km. Beyond that depth, all you'd need would be soft tubing to conduct it to the bottom without mixing with seawater. Once there, a layer of plastic film would keep it in a "CO2 lake".
I've also thought about catching, distilling and sequestering CO2 from undersea vents, which may be a major source of it. Pictures have shown droplets of liquid CO2 temporarily suspended in rising, apparently CO2-saturated, water from vents. It might be possible with minimal technology, energy supplied by the heat of the vents, without necessarily harming nearby life.
Truth be told, I thought that the solutions shown on this article are not available to come true. Becasue It has low effieciency and must accelate entropy which usually used in thermodynamic. new technology suggested for reducing pollutions have been increasing disorder of nature . for example, For example, I would like to suggest nuclear power plant. Absolutely it has advatage such as reducing carbon dioxide eventhough remains uranium. But we need to consider the process of it. How to cool the system... Actually we can use sea or river, then how many water will be used...
Reply | Report Abuse | Link to thisThe flow rate would be huge... more than your thingking. And
as we operate power plant, the tempeature ger warmer then warmer.
Yes, we will just launch the ship into the sun when it is night time.
Reply | Report Abuse | Link to thisNo, sometimes the stupidity of the world disturbs me. I have absolutely no Idea how launching a ship full of people into the sun or the moon will help improve the environment. Perhaps when we roast some people in the sun it will please the air gods and remove tons of Carbon Dioxide from the atmosphere. No, what we really need is a ring of solar panels across the equator of the earth, and using mirrors to increase the amount of solar energy absorbed by the mirrors, we can reduce the amount of fossil fuel burning necessary to fuel households today, therefore reduce global warming and perhaps preventing another Younger Dryas effect.
Hey Arctic Biscuit You are looking great today.
Reply | Report Abuse | Link to thisI know, I also feel brilliant.
Reply | Report Abuse | Link to thisBy the way, there is a man who thinks he is a deck of cards outside.
Reply | Report Abuse | Link to thisThats Ok, I'll deal with him later.
Reply | Report Abuse | Link to thisHow Punny.
Reply | Report Abuse | Link to thisI know, I should be PUNished.
Reply | Report Abuse | Link to thisYolo bananas
Reply | Report Abuse | Link to this#swag4Life YOLO
Reply | Report Abuse | Link to thisYou know whats really Ironic?
Reply | Report Abuse | Link to thisDriving an electric Prius that runs off of electricity made by a giant coal plant, which farts off a complete amount extreme Carbon Dioxide.
yolo fact of the day: bananas have a high amount of vitamen Z
Reply | Report Abuse | Link to thisHi this is the real Arctic Biscuit. My little brother managed to get onto my account and act like a complete dingus. Please feel free to laugh at the previous posts and ignore all but my first comment and this one. But, alas, you never know if I'm lying, because I lie all the time, like right now.
Reply | Report Abuse | Link to thisThe only Vitamen I know is Viagra
Reply | Report Abuse | Link to thisI'm sorry fellow scientists, I will soon have to disable this account if my brother continues to play with my account. For all I know, he is standing behind me and is going to smash my face into the rapodsz;xkcljvaoiwertlzx;kckvh'oiadsfya.jkbwe ,a;keudfhvzxcuvyaw.kj;ek4ewto8up8u2p983rp98jkzxchv iu;oiua;flawe;lkz;xcuiovp98a7es6pq983kjb;.cjk;vuz;xfdetopilieraup98z7xcv;jakj;e,asdf,m;fioyzxcvotiqe9ehaglha,.vknbjcgviydtifhwjn5
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