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Scientists Plan "Artificial Volcano" Climate Experiment
First time accepted submitter tonyt3 writes "Scientists plan on conducting an unusual climate experiment at a Norfolk airfield next month. They plan to spray water into the air about 20 km high to mimic volcanic particles, hoping that their findings could lead to a solution to global warming. From the article: 'Pouring 10 million tonnes of material into the stratosphere each using 10 to 20 giant balloons could achieve a 2C global drop in temperature, the scientists believe. Sulphate emissions from the Mount Pinatubo eruption in the Philippines in June 1991 reduced world temperature by 0.5C for two years.'"
The air's pretty thin 1000 km up -- considering that the Space Station orbits at less than half that. Maybe 10 km?
-- Alastair
...this totally blows away my papier-mache-and-baking-soda model.
I bet those guys are going to win the Science Fair.
Sometimes you're on a crowded bus and you can tell that the person next to you decided they didn't have time to actually get clean, but thought they could mask their odor with deoderant. Unfortunately, in some cases, what you get is a retch-inducing mixture of BO and deodeo.
Solutions like this to the climate issue remind me of those folks on the bus. If there's a real problem and if there are real things we can do to address the cause, let's do them. If, instead, we don't address the cause but do something else to mask the issue, then it seems likely that we'll just end up with an even bigger mess. I can just imagine scientists from another planet examining the burnt out husk of Earth and saying, "There's no life there; the atmosphere is an unlivable mix of carbon dioxide and sulphates!"
The CB App. What's your 20?
I'd much rather save the earth by spending and using less than dumping even more crap into the air. Quick fix anyone?
I'm glad scientists are working on ideas like this. The reality is that we, the human race, are not going to stop burning fossil fuels. We'd best get on with figuring out how to deal with the resulting problems rather than continue dreaming that everyone is going to agree to stop.
It's like a smoker using air filters to clean up second hand smoke. Sure it may reduce the consequences of their actions, but it doesn't negate the fact that the addiction is the source of their problem.
That being said, I don't want to dismiss their research altogether. The data will probably be useful for improving climate models and we may just have to resort to such tactics since we've been doing relatively little about climate change even though we've been aware of the issue for decades.
Except that the water vapor in the atmosphere is largely there because the carbon dioxide has made it warm enough. Remove the carbon dioxide and we all freeze (among other problems).
a,e,i,o,u and sometimes w and y (at be if of up cwm by)
This is just a first test of the technology. If they were really going to use this for climate engineering, they'd use "clay, salts or metallic oxides suspended in liquid" (according to TFA) to reflect some sunlight back into space before it hits the earth.
As you can imagine, just figuring out whether you can pump millions of kilograms of stuff 1,000 meters into the air (not 1,000 km, as the submitter wrote) is an open question. Their ultimate goal is to get it 20 km up. For the first test, you use what's cheap: water.
The water itself is a greenhouse gas, but water molecules condense and fall as rain. It quickly returns to the existing equilibrium. The goal is to put up particles that would stay there for a while. Unlike water, they don't condense and fall out as quickly.
Before it fell, the water would reduce sunlight a bit. Water vapor is a greenhouse gas, but water in clouds isn't vapor; it's condensed droplets. Those droplets can reflect light; that's why cloudy days are dark. The goal isn't to produce water clouds, which would only be temporary and would be too much darkening. The goal is to put up enough particulates to get a slight reduction of incident light without having to continually pump new particles into the atmosphere.
(Note: I'm not crazy about geoengineering as a solution to climate change, but the experiment is still interesting.)
Argh, blargh. I really hate it when people are so sure about completely wrong science, especially as their aggressive misinformation is being exploited by civilizational sociopaths.
I am usually nice on the internet, but this will be an exception.
Slashdot posters usually have some knowledge of Newtonian mechanics 101 and will rightly laugh at those who don't believe in say, conservation of momentum.
Well, this is the same level of blunder, so here goes the explanation, as nice as I can make it without wanting to strangle internet ignoramuses.
Yes, water is a greenhouse gas, and yes every climate scientist since 1900 or whatever has known this, and there has never been any conspiracy to "suppress" this, especially given that the water cycle is at the core of every weather and climate model and observational data set.
And human "emissions" of water are completely and totally irrelevant (say like the post above) because the planet is in statistical equilibrium with those very large sources of water known as "oceans". Water, namely vapor and clouds, are *feedbacks* with timescales of two weeks, vs dozens to thousands of years for carbon dioxide. For example, if you magically took all the water out of the atmosphere, how long would it take to get back to normal? A few weeks. If you magically saturated the atmosphere completely with water, how long would it take to get back to normal? A few weeks. If you magically took all the CO2 out of the atmosphere, how long would it take to get back to normal? Many, many millions of years.
The amount of water in the atmosphere is determined in large measure, by,what---yes the temperature! Hotter air absorbs more water, and yes, the water vapor will add its own greenhouse effect. The water vapor amplifies global warming which was induced by the excess of long-lived greenhouse gases like CO2 (and others) introduced by human activity. (Clouds are less certain---they may go both ways for heating/cooling in various cases, this is a complex area of current study---but the base level effect of vapor {clear, humid air} is undisputed and significant)
The scientists who have been studying this for decades know what they're talking about.
Greenhouse gases raise Earth's temperature from from 260 K to 288 K. If CO2 is responsible for 10% of that, it's responsible for a 2.8 K temperature change. If we assume the temperature change is linear with the amount of CO2 a doubling of the CO2 in the Earth's atmosphere will result in a 2.8 K temperature increase. Which is within the range of temperature change climate scientists predict for a doubling of the CO2 in Earth's atmosphere.
So why do you think your little factoid is an argument against global warming?
It's also generally accepted that these are not independent, since increases in CO2, CH4, and O3 increase the temperature, which increases the water vapor: "The average residence time of a water molecule in the atmosphere is only about nine days, compared to years or centuries for other greenhouse gases such as CH4 and CO2. Thus, water vapor responds to and amplifies effects of the other greenhouse gases."
(2) "and that the amount generated by human activity is further less than 10% of that CO2."
The CO2 in the atmosphere has increased from 270-280 ppm a century ago to 390 ppm today (and it was down to 180 ppm in the last ice age). 390/280 = 40% increase. And, before you say that not all the 110 ppm increase is due to human activity, I submit this graph showing that CO2 levels over the past 600,000 years have never been above 300 ppm until the 20th century ( http://static-www.icr.org/i/articles/af/does_carbon_dioxide_fig3new.jpg )
You know: I'd think there was a lot more to climate change denial if the facts presented by climate deniers weren't almost always wrong.
I would be interested to know, though, how they think this would lower the temperature - for example: if water vapor at different elevations have different effects.
Yes. The animals and birds and glaciers don't respond to human biases, and what they're doing is clear indication of warming.
The denialists are getting worse---they started out saying "there's no warming" (after the 1990's volcano had some temporary cooling), and then when the warming got clear, they said "well we don't know that people are responsible" (after all it could be magic fairys who just happen to change infrared emissivity of the atmosphere in exactly the way predicted by liberal-infected chemistry professors say that greenhouse gases do, when of course they don't, because in the atmosphere they're special and closer to heaven and don't have the same vibrational modes that they do in the lab). And now they're going back to denying that there's warming at all?
Except the idea is not to lift tons of stuff, but a pipe that pumps the stuff up and sprays it. The balloon only needs to lift the pipe and the fluid in the pipe at any time, not the total of the fluid pumped up over the course of the project.
APK likes to ask for responses to the same things over and over. Maybe he just likes the responses?
Any scientist who is a proponent of AGW theory is pure as the driven snow, honest, no ulterior motives, and with no allegience to those writing the paychecks. His goal is purely the science.
Any scientist who is a skeptic of AGW theory is an evil troll, dishonest, greedy, wants to destroy the Earth with his SUV and other wasteful habits, and will produce any result those who are funding him dictate.
At least that's how it appears the true believers see it, the ones who have lost the ability to be skeptical.
The Sun provides the incoming energy. Without the greenhouse gases in the atmosphere blocking some of the outgoing IR radiation the average temperature on the surface of the Earth would be around 0F (-17.7C) instead of 58F.
Nonsense. Models predict no discernible change over the last ten years. Besides, I think our Anonymous Cowards run quite enough.
a,e,i,o,u and sometimes w and y (at be if of up cwm by)
For thousands of years since the end of the last glaciation around 10,000 years ago the CO2 level in the atmosphere hovered around 280 ppmv. Every year, tracking the seasons, the level fluctuated about 10 ppmv going down as plants grew in the northern hemisphere spring/summer and going back up as stuff decayed in the northern hemisphere autumn/winter. It's all part of the carbon cycle which holds a balance of carbon between the atmosphere, hydrosphere and biosphere (with the geosphere playing a minor role). The carbon in fossil fuels had been sequestered from the carbon cycle for many millions of years but now we are releasing it back into the carbon cycle so a new balance is being created with more carbon in all of the "-spheres". It's quite clear that the increase of carbon in the carbon cycle is due to human activities releasing the fossil carbon.
You're right, helium is too precious to be used for more than the initial tests. Once they get into unmanned platforms far out to sea, there is really no reason not to use hydrogen. It should be possible to arrange it so that if there is an fire nearly everything but the envelope itself can be salvaged.
The amount of lift needed will less than 100,000 tonnes. A 50cm diameter x 20km column of water weighs less than 4000mt. The pipe will have to have some serious walls, though - that's nearly 2000 bar just from hydrostatic pressure, and much more will be needed to push the water -the article states 4000bar. Allowing 50% extra length for the curve and figuring the weight including the hose wall as equivalent to a 64cm diameter column of water, that is about 10000 tonnes. The envelope will have to be huge, though, and it will weigh much more, about 72 tonnes if I've done my math right. (Figuring 1250m length, fineness 2.8 ellipsoid, 50g/m^2 envelope (higher weight envelope figured to allow for airbeam skeleton/keel), net lift of 0.8N/m^3 for H2 at 20km standard atmosphere.) A bit more lift is needed for reserve lift, other equipment and the higher density of salt water, but the total should be in the neighborhood of 100,000 tonnes.
That size pipe at that pressure should deliver about 3 or 4 cubic meters per second if the water is going at 15-20m/s (~35-45mph). At the higher flow rate, that would be about 785MW just to lift the water, and over 1.6GW including pipe friction. That's about 1/8 km^3 per year and about 5e16 Joules/year.
The water will need to be atomized - Prof. Stephen Salter of the University of Edinburgh designed an elegant, efficient and reliable way of atomizing such large volumes of water in his paper "SPRAY TURBINES TO INCREASE RAIN BY ENHANCED EVAPORATION FROM THE SEA". (The rain-making part didn't work, as the spray suppressed natural ocean eveporation by increasing humidity.) The atomization should not take a relatively significant amount of power, less than 1MW.
It may be possible to offset the energy cost by using wind power. The wind will do work on the charged water spray, which will be carried a long way, turning into microscopic salt-crusted condensation nuclei before being rained out, mostly into the ocean, which could act as a current return path. The work of the wind would be turned into a higher voltage on the droplets by capacitive voltage multiplication (costant charge on the droplets, increasing distance from the spray electrode -> lower capacitance, higher voltage). A direct wind-electric energy conversion should be possible, though how much power it would produce is an open question.
"Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery?" - Patrick Henry
Pipe friction losses will more than double the energy needed. OTOH it should be able to offset a bit of that with wind. Solar would only offer a percent or two of the energy needed, even if it covered the whole upper surface of the balloon, and the weight and expense would make it impractical.
Harnessing the wind could potentially be better, given the high and relatively constant winds in the stratosphere. Because of the nearly 20x lower density, though, the ~15m/s (34mph) median stratospheric wind speed's average energy content per area is about equivalent to an 14mph (6.25m/s) breeze at sea level. (~88W/m^2 Betz limit).
With the vast quantities of electrostatically charged droplets produced by the sprayers and the huge size of the droplet plume, a direct conversion of wind energy to electricity with an enormous effective wind capture area should be possible. The wind will pull the charged droplets away from the oppositely charged sprayer, doing work and increasing the voltage between them. The droplets will eventually settle out onto the oppositely charged ocean, completing the circuit. A load such as a pump can be hooked between the ocean potential and the sprayer potential. (An insulating layer between the ocean potential and the sprayer potential is needed, which can in principle be achieved by having the pump body be nonconductive, isolating the two sides of the circuit in the same way a revolving door prevents a free flow of air. The actual system would be in multiple stages, as it would have to withstand megavolts to keep the currents in the tether manageable while transmitting many hundreds of megawatts.)
With plumes over a km thick and several km wide, (dozens of km^2) the system could potentially power itself, or even produce a surplus.
"Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery?" - Patrick Henry
(1) "It's supposed to be a secret that CO2 accounts for less than 10% of greenhouse gases"
Perhaps he got Wikipedia and Wikileaks mixed up in his head again?
More like wikipedia and conservapedia.
The world you experience is only a close approximation of reality.