Guest Post by Willis Eschenbach
I noted on the news that there is a new plan afoot to cool down the planet. This one supposedly has been given big money by none other than Bill Gates.
The plan involves a fleet of ships that supposedly look like this:
Figure 1. Artist’s conception of cloud-making ships. Of course, the first storm would flip this over immediately, but heck, it’s only a fantasy, so who cares? SOURCE
The web site claims that:
Bill Gates Announces Funding for Seawater-Spraying Cloud Machines
The machines, developed by a San Francisco-based research group called Silver Lining, turn seawater into tiny particles that can be shot up over 3,000 feet in the air. The particles increase the density of clouds by increasing the amount of nuclei contained within. Silver Lining’s floating machines can suck up ten tons of water per second.
What could possibly go wrong with such a brilliant plan?
First, as usual the hype in this seems to have vastly outpaced the reality. According to CBS News Tech Talk:
The machines, developed by a San Francisco-based research group called Silver Lining, turn seawater into tiny particles that can be shot up over 3,000 feet in the air. The particles increase the density of clouds by increasing the amount of nuclei contained within. Silver Lining’s floating machines can suck up ten tons of water per second. If all goes well, Silver Lining plans to test the process with 10 ships spread throughout 3800 square miles of ocean. Geoengineering, an umbrella phrase to describe techniques that would allow humans to prevent global warming by manipulating the Earth’s climate, has yet to result in any major projects.
However, this is just a quote from the same web site that showed the ship above. CBS Tech Talk goes on to say:
A PR representative from Edelman later sent me this note from Ken Caldeira of the Carnegie Institution for Science: “Bill Gates made a grant to the University of Calgary to support research in possible unique solutions and responses to climate change. Administrating this research funding, David Keith of the University of Calgary and I made a grant to Armand Neukermanns for lab tests to investigate the technical feasibility of producing the fine seawater sprays required by the Latham cloud whitening proposal, one of many proposals for mitigating some of the adverse effects of climate change. This grant to Neukermanns is for lab tests only, not Silver Lining’s field trials.”
So Bill Gates isn’t funding the ships, and didn’t even decide to fund this particular fantasy, he just gave money to support research into “possible unique solutions”. Well, I’d say this one qualifies …
Next, after much searching I finally found the Silver Lining Project web site. It says on the home page:
The Silver Lining Project is a not-for-profit international scientific research collaboration to study the effects of particles (aerosols) on clouds, and the influence of these cloud effects on climate systems.
Well, that sure sounds impressive. Unfortunately, the web site is only four pages, and contains almost no information at all.
Intrigued, I emailed them at the address given on their web site, which is info(a)silverliningproj.org. I quickly got this reply:
Delivery has failed to these recipients or distribution lists:
info@silverliningproj.org
The recipient’s e-mail address was not found in the recipient’s e-mail system. Microsoft Exchange will not try to redeliver this message for you. Please check the e-mail address and try resending this message, or provide the following diagnostic text to your system administrator.
Hmmmm … not a good sign, four page web site, email address is dead … but onwards, ever onwards. Let’s look at a few numbers here.
First, over the tropical oceans, the rainfall is typically on the order of a couple of metres per year. Per the info above, they are going to test the plan with one ship for every 380 square miles. A square mile is about 2.6 square km, or 2.6 million square metres. Three hundred eighty square miles is about a thousand square km. Two metres of rainfall in that area is about two billion tonnes of water …
They say their ships will suck up “ten tonnes of water per second”. That’s about a third of a billion tonnes per year. So if they run full-time, they will increase the amount of water in the air by about 15% … which of course means 15% more rain. I don’t know how folks in rainy zones will feel about a 15% increase in their rainfall, but I foresee legalarity in the future …
Next, how much fuel will this use? The basic equation for pumps is:
Water flow (in liters per second) = 5.43 x pump power (kilowatts) / pressure (bars)
So to pump 10,000 litres per second (neglecting efficiency losses) with a pressure of 3 bars (100 psi) will require about 5,500 kilowatts. This means about 50 million kilowatt-hours per year. Figuring around 0.3 litres of fuel per kilowatt-hour (again without inefficiencies), this means that each ship will burn about fifteen million litres of fuel per year, so call it maybe twenty five million litres per year including all of the inefficiencies plus some fuel to actually move the ship around the ocean. All of these numbers are very generous, it will likely take more fuel than that. But we’ll use them.
Next, the money to do this … ho, ho, ho …
You can buy a used fire fighting ship for about fifteen million dollars, but it will only pump about 0.8 tonnes/second. So a new ship to pump ten tonnes per second might cost on the order of say twenty million US dollars.
You’d need a crew of about twelve guys to run the ship 24/7. That’s three eight-hour shifts of four men per shift. On average they will likely cost about US$80,000 per year including food and benefits and miscellaneous, so that’s about a million per year.
Then we have fuel costs of say US$ 0.75 per litre, so there’s about ten million bucks per year there.
Another web site says:
A study commissioned by the Copenhagen Consensus Centre, a European think-tank, has estimated that a wind-powered fleet of 1,900 ships to cruise the world’s oceans, spraying sea water from towers to create and brighten clouds, could be built for $9 billion. The idea would be to operate most of the ships far offshore in the Pacific so they would not interfere with weather on land.
My numbers say $38 billion for the ships … and “wind-powered”? As a long time sailor, I can only say “get real” …
However, that’s just for the ships. Remember that we are talking about $11 million per ship for annual pumping fuel costs plus labour … which is an annual cost of another $20 billion dollars …
Finally, they say that they are going to test this using one ship per 380 square miles … and that they can blanket the world with 1,900 ships. That makes a total of around three quarters of a million square miles covered by the 1,900 ships.
The surface of the world ocean, however, is about 140 million square miles, so they will be covering about half a percent of the world ocean with the 1,900 ships. Half a percent. If that were all in the Pacific Ocean per the citation above, here’s how much it would cover:
Figure 2. Area covered by 1,900 cloud making ships.
Yeah, brightening that would make a huge difference, especially considering half of the time it wouldn’t even see the sun …
See, my problem is that I’m a practical guy, and I’ve spent a good chunk of my life working with machinery around the ocean. Which is why I don’t have a lot of time for “think-tanks” and “research groups”. Before I start a project, I do a back-of-the-envelope calculation to see if it makes sense.
My calculations show that this will cost forty billion dollars to start, and twenty billion per year to run, not counting things like ship maintenance and redundancy and emergencies and machinery replacement and insurance and a fleet of tankers to refuel the pump ships at sea and, and, and …
And for all of that, we may make a slight difference on half a percent of the ocean surface. Even if I’ve overestimated the costs by 100% (always possible, although things usually cost more than estimated rather than less), that’s a huge amount of money for a change too small to measure on a global scale.
Now Bill Gates is a smart guy. But on this one, I think he may have let his heart rule his head. One of the web sites quoted above closes by saying:
The Bill and Melinda Gates Foundation did not respond to requests for comment on Tuesday, nor did U.S. entrepreneur Kelly Wanser, who is leading the Silver Lining Project.
Smart move … what we have here is a non-viable non-solution to a non-problem. I wouldn’t want to comment either, especially since this non-solution will burn about 27 billion litres (about 7 billion US gallons) of fuel per year to supposedly “solve” the problem supposedly caused by CO2 from burning fuel …
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@ur momisugly Anna V
From same paper:
““5. Spray generation.
Each rotor has a Grundfoss down-hole pump that feeds 17 m3 s−1 to a bank of eight filters with blister valves to allow any filter to be back-flushed.”
17 m3/s = 61200 m3/h
567 times more.
See my previous post
Julian flood says: “Are you seriously suggesting that the exhaust from a ship’s funnel … is at 1000 degrees? Next time you drive a diesel car, get out with the engine running and put your hand in the outflow from the exhaust.”
OK Julian, 1000 degF is too high, but why don’t you try grabbing the exhaust manifold and tell us how you get on. I can guarantee the “flesh turning black and crispy” experience you mention.
So – into the real world and onto figures. We can refer this to the real experts – like Finnish ship engine manufacturer, Wärtsilä.
In the following sheet you will see mention of 784 degF engine outlet temperature:
http://www.energysolutionscenter.org/DistGen/AppGuide/Manf/Wartsila.htm
Not good to stick your hand into that.
Where economics and space allow, is is preferable to pass the exhaust gas through a waste heat recovery boiler to raise superheated steam and improve overall cycle efficiency. An example in this sheet:
http://www.wartsila.com/Wartsila/global/docs/en/ship_power/media_publications/brochures/product/waste-heat-recovery-wartsila.pdf
Exhaust gas temperature is lowered to 166 degC. Still no place for hands!
Why not lower the exhaust gas even further? As I mentioned above, it’s essential to stay above dew point to avoid condensation, acid formation and corrosion. But there is still work to do in getting those gases aloft, so the gases need to be hot enough for plume buoyancy.
Oh yes – that reminds me – no answer to my suggestion that we simply seed to thousands of plumes which reliably and effectively raise vast volumes of gas into the middle atmosphere every day. So why spend £bn on fancy ships?
Or is that an awkward question when papers have already been published?
Ship’s Stacks used to leave trails of Smoke… clearly, those streamed BEHIND the ship. Nonetheless, SOMETHING caused a disturbance high above.
Custer’s lonely Hill offered a view down a Valley that showed, ON PHOTOs, a disturbance high over where 2 highways cross today — which, being where a Supply Steamboat was on HIS day, implied that when Custer saw the smoke, he HAD TO keep Sioux Lookouts off THAT HILL – – even with smelly dead bodies. Yuck. Lest the Sioux see, and move to find a Treasure trove of ammunition on the ship. At least, that was my theory. To be seen 20 miles off, it had to rise HIGH.
Clearly, various Particulates rise … e.g. SMOG … heat may help, but air also Diffuses things. Ship’s stacks are typically many feet wider than the engine outlet, cutting the temp-over-ambient by 10 times or more. Lest the Paint be melted off the Stack. So they are NOT high-temp … but … still ARE warm. Is it heat or Vapor Pressure driving the results ?
I think we will only find out if enough of it floats 3000 feet up … by actually trying. Which is why they are building a Test.
PS: And what of the Arctic ?
Modern Icebreakers steam backwards & use Propellor action to shape the Ice around the ship into a teardrop flow– so the Ice breaks itself up. No props here. Any ideas ?
http://shipsandharbours.com.s3.amazonaws.com/4071.jpg
shows the normal picture one expects. If one googles ‘ship smoke’ there are pictures of all sorts of behaviour, but few of three thousand foot columns powering up to the inversion layer. Mostly it’s a blob of smoke drifting idly away — ie what you normally see.
Some idea of how easy it is to make clouds can be seen by googling ‘windmills sea mist’. The first hit is an article which shows how the small stirring of a windfarm can create sea mist a couple of hundred feet thick. How gratifying that windmills really do cool the Earth, albeit using a different mechanism than that normally proposed. Your tax dollars at serendipitous work.
If the windmill/fog phenomenon is predictable then we could experiment with it. I’d love to be out there with twenty gallons of olive oil and a speed boat, with Cessna 150 photographic top cover.
JF
Jordan says:
May 14, 2010 at 2:35 pm
Oh yes – that reminds me – no answer to my suggestion that we simply seed to thousands of plumes which reliably and effectively raise vast volumes of gas into the middle atmosphere every day. So why spend £bn on fancy ships?
Or is that an awkward question when papers have already been published?
There are a lot of geoengineering proposals.
An old suggestion is to mimic volcano outputs with all planes jetting around so the contrails by adding aerosols .
The problem is that what would be added, sulfur and such, would not be easily removed if suddenly a real volcano blew up or somehow the ice age started coming in real. It takes years for aerosols to settle.
I have not heard of adding salt to the contrails, that would also be non destructive and removed with the first precipitation.
We are discussing the feasibility of this proposal. The fixed stacks and the boats that already exist do not optimize the distribution as a controlled robotic setup would to cover larger areas. And again you would have the problem of the extra energy/fuel needed to create and spew the salt spray.
Oh, dear dear.
I can see why prof. Salter stopped responding.
Lance says:
May 14, 2010 at 1:16 pm
@ur momisugly Anna V
From same paper:
““5. Spray generation.
Each rotor has a Grundfoss down-hole pump that feeds 17 m3 s−1 to a bank of eight filters with blister valves to allow any filter to be back-flushed.”
17 m3/s = 61200 m3/h
567 times more.
You are good at arithmetic, grant you.
Also in picking random numbers in order to make a point.
Each rotor has a Grundfoss down-hole pump that feeds 17 m3 s−1 to a bank of eight filters with blister valves to allow any filter to be back-flushed. Norit X-flow filters have an excellent record for pre-filtration in reverse osmosis desalination plant (van Hoof et al. 1999). A trash-grid made from titanium mesh will prevent jelly fish and plastic bags from jamming the pump.
In my dictionary, flushing means instantaneous or at most a few minute use of pumps.
You calculation assumes hours. The pumps may need megawatts for continuous usage, but will only be used for flushing and the instant power.
Dr. Joel Norris of the Scripps Institution gave an excellent presentation to the Fermilab colloquium this week, and I’ll post the video when Fermilab has it on their site.
To summarize his thoughts, nearly all of the IPCC models did not agree at all with the observations of clouds, there are many deficiencies in measuring cloud cover, and nobody knows what the hell all this means.
This is a good overview of his thoughts….I’d cool it on the “man-made clouds” stuff until we have a better handle on what the effect would be. There’s a pretty good chance that the lower clouds would just make warming worse.
http://meteora.ucsd.edu/~jnorris/reprints/PacCloudFeedback.pdf
Science 325, 460 (2009);
Amy C. Clement, et al.
“Observational and Model Evidence for Positive Low-Level Cloud Feedback”
Charles Wilson says: ” Lest the Paint be melted off the Stack. So they are NOT high-temp … but … still ARE warm.”
The manufacurers have already spotted that problem. The painted stack (funnel) you see is an outer shell. The hot ducting is protected from the elements and runs inside the funnel. Here’s a good example:
http://img3.photographersdirect.com/img/13725/wm/pd429091.jpg
Julian: “few of three thousand foot columns powering up to the inversion layer”
Yes it gets windy out at sea, and that can cause the exhaust emissions to be blown nearly sideways. The mixing and dispersing plume can get back down to sea level, but the idea is still to get as much of the plume to head upwards, and there really is no othere way to do it. (Ever wondered why land-based industrial complexes have very tall stacks? And therefore you rarely have the experience of smelling their emissions?)
anna v says: “We are discussing the feasibility of this proposal. The fixed stacks and the boats that already exist do not optimize the distribution as a controlled robotic setup would to cover larger areas. And again you would have the problem of the extra energy/fuel needed to create and spew the salt spray.”
Here is a photo of the type of thing that goes on around the globe every single day:
http://wwwdelivery.superstock.com/WI/223/1598/PreviewComp/SuperStock_1598R-150374.jpg
There are thousands of similar locations around the globe – so there is already a way to manage distribution using what we have sitting on the ground today. No need to send massive automated vehicles adrift one the open seas.
These machines are designed to move massive volumes of gas high into the air. On volume flow alone, they have the capacity to transport much more CCNs aloft than 10 tonnes per second of brine.
I don’t know anything about cloud seeding or its effectiveness, but I would not expect a small dosing plant to add much to cost.
Spending £bn on designing and then building these ships will consume a lot of energy. As Willis says, the sea is a harsh environment, so there would be ongoing money energy expenditure in repair and maintenance. And we’d also need to consider losses – even the manually operated ships occasionally get into difficulty and end up either sinking or washed up on a shore somewhere.
If prof. Salter stopped responding, at least he can say that he heard it here first.
Anna, where do you see time in the pump power calc? Time is irrelevant for power (watt).
Wether you pump 61200 m3/h @ur momisugly 3 bar for one second or three hours, you still need 5 MW to do it.
And why would you need 61000 m3/h to flush a filter designed for 180 m3/h?
@ur momisugly Anna:
Apologies, 108 m3/h (30 kg/s) of course, not 180.
maybe we read this sentence differently:
““5. Spray generation.
Each rotor has a Grundfoss down-hole pump that feeds 17 m3 s−1 to a bank of eight filters with blister valves to allow any filter to be back-flushed.”
I read that *the blister valves* are what allow backflushing, not the 17 m3/s.
You probably read that 17m3/s is used for the flushing.
But I think they mean that the 17 m3/s goes through the eight filters and on to the atomizing mesh, hence the chapter name “Spray generation”.
I cannot imagine needing 567x more than normal flow for backflushing a filter -there is the arithmetic again, and by the way thanks for the compliment! 😉
so which is it, 108 m3/h of water sprayed into the air, or 61200 m3/h (17m3/s, which is at least orders of magnitude closer to the 10 ton/s Willis’ post mentions)?
Sorry one more thing:
Anna, u asked @ur momisugly 12:19h:
“Where did you get the 9500liters/second?”
That was from my first post describing the pumps in the cooling water system I described, which produce a flow in the neighborhood of the 10.000 liters/s Willis mentions.
Lance says:
May 15, 2010 at 3:47 am
The implication of your statement was that they needed this power continuously, because you confused it with the power necessary to produce the spray.
One can get a lot of power for small intervals, in various ways.
http://en.wikipedia.org/wiki/Grid_energy_storage
For example in Puerto Rico a system with a capacity of 20 megawatts for 15 minutes
And why would you need 61000 m3/h to flush a filter designed for 180 m3/h?
Your vacuum cleaner should tell you. You need a lot of power to pull up fluff, for a short interval.
If the nozzles are clogged, blowing with a powerfull reverse flow will clean them. It is called flushing.
As I pointed out Willis has been solving for a different problem.
Lance
It is the context, the context:
http://rsta.royalsocietypublishing.org/content/366/1882/3989.full
A weakness of the micro-nozzle approach is that particles much smaller than a nozzle can form an arch to clog it. Fortunately, the need to remove viruses from ground water for drinking purposes has produced a good selection of ultrafiltration products that can filter to a better level than is needed. Suppliers guarantee a life of 5 years provided that back-flushing can be done at the right intervals. Each rotor has a Grundfoss down-hole pump that feeds 17 m3 s−1 to a bank of eight filters with blister valves to allow any filter to be back-flushed. Norit X-flow filters have an excellent record for pre-filtration in reverse osmosis desalination plant (van Hoof et al. 1999). A trash-grid made from titanium mesh will prevent jelly fish and plastic bags from jamming the pump. If it is fed with a current of 90 amps, it can also produce 2 ppm electrolytic chlorine to prevent biological growths.
Electrical energy for spray and rotor drive will be generated by a pair of 2.4 m diameter axial-flow turbines on either side of the hull as shown in figure 10. These are very much larger than any propellers needed for a vessel of this size but can act as propellers for 10 hours in windless conditions using energy from a bank of Toshiba SCiB batteries.
This whole thread makes want to quote my swallow story, so I will:
The Swallow
When God created the swallow, a migrating bird that winters in Africa, He started to show him how to build his nest. He showed how to make small mud balls with his tongue and how to gradually build up the nest; but He was interrupted just before reaching the point where He started to show the swallow how the nest should get covered and have a roof. The swallow, half paying attention flexing its wings and ready to fly off swiftly after juicy flies and mosquitoes said “OK, OK, I know, I know” and flew away.
That is why swallows’ nests are only half built and they have to be under a roof or an outcropping. The swallow never had the patience to listen to the end of the demonstration.
As so many people on this thread.
@anna:
Besides the backflush error:
All the referenced news articles mention that each ship can suck up 10 tons/s. For instance:
http://inhabitat.com/2010/05/10/bill-gates-announces-funding-for-seawater-spraying-cloud-machines/
“Silver Lining’s floating machines can suck up ten tons of water per second.
If all goes well, Silver Lining plans to test the process with 10 ships spread throughout 3800 square miles of ocean. Even if that goes well, the technology has a long way to go before it can significantly alter the climate — a recent study showed that it would it take 1,900 ships at a cost of over $7 billion to stop Earth’s temperature from rising.”
All references, except for the paper, which mentions 30kg/s for each ship. Which makes sense given the 150 kW statement in same paper.
ok, so 300 ships are needed (30kg/s each) to get 10 tons/s into the air.
Does that mean that the 1900 ships required to “stop Earth’s temperature from rising” only spray 63 tons/s into the air (0,05% of the annual rain fall in tropical waters), which is supposed to stop AGW?
Industrial self cleaning backwash filters used in large cooling water systems need 5% of normal flow for backwashing purposes, for a couple of minutes at regular intervals.
56.700% backflush flow does not make any sense, sorry.
Lance,
Please read the link you provided, and see that the objective is not to increase rain.
The objective is to increase albedo by 1%, because a 1% change in albedo=reflectivity-of-clouds will cancel the energy supposedly produced by a doubling of CO2. They believe that they can do it with their proposal, and have numbers for condensation nuclei. Look at fig2.
Right in the abstract:
and so will increase the cloud albedo to reflect solar energy back out to space. If the possible power increase of 3.7 W m−2 from double pre-industrial CO2 is divided by the 24-hour solar input of 340 W m−2, a global albedo increase of only 1.1 per cent will produce a sufficient offset. The method is not intended to make new clouds. It will just make existing clouds whiter.
The objective is to increase albedo by 1%, because a 1% change in albedo=reflectivity-of-clouds will cancel the energy supposedly produced by a doubling of CO2. They believe that they can do it with their proposal, and have numbers for condensation nuclei. Look at fig2.
What is this thread, a bad tutoring session?
anna: “One can get a lot of power for small intervals, in various ways.”
Large scale energy storage incurs significant losses. You’ll struggle to get above 85% turnaround efficiency. But you’ll do a lot worse than that if other factors force the design down certain technology routes.
A good deal of the above discussion concerns how to make the whole concept work from very limited available energy. A key design objective is to avoid conversion of energy from one form to another because it will always cause your limited energy supply to leak away. Suggesting energy storage for surges of power is not exactly going to help in that respect.
If transporting CCNs into the middle atmosphere is such a good idea, what’s wrong with dosing the plumes of the power stations and indutrial complexes we already have all over the place? They are not going to dissapear anytime soon – unless we completely give up our way of life.
Or is there something that will not work in dosing these plumes? If if there a problem with dosing industrial plumes, will it still work for a mist of brine, drawn and filtered from the sea?
For various reasons, Willis is basically correct – this is a bad solution to a non-problem. Why continue to discuss it and run into to yet more impracticalities.
Jordan says:
May 15, 2010 at 9:24
For various reasons, Willis is basically correct – this is a bad solution to a non-problem. Why continue to discuss it and run into to yet more impracticalities.
Because Willis is basically not correct, that is why. His post solves a different problem, it is not examining the proposal under hand.
I suppose I am naive but I expected the readers of this blog to easily avoid running after red herrings and to be able to separate the wheat from the chaff of science.
Yes, CO2 is a non problem. All geo engineering proposals are solutions to this non problem that have to be weighted against the damage of cap and trade for the western civilization. If you have world governments believing in Apollo and taking decisions according to oracles you will not be able to change their decisions by denigrating the oracles. You have to support the oracular sayings that do the least damage.
Let me recapitulate.
I think that the proposal as seen in http://rsta.royalsocietypublishing.org/content/366/1882/3989.full
has merit and is worth building a prototype of, because of the small expense relative to the billions wasted on AGW studies, and because it is innocuous, i.e. non permanent with respect to the environment.
To have a major skeptics blog come out on a witch hunt against it , running after red herrings at that, is not constructive for what should be the future aim of all thinking scientists: avoid cap and trade, wait it out until the PDO convinces people that there is no A in GW.
I think this is my last on this.
Dear Anne,
I keep trying to make you look at the basic numbers.
You completely ignore all of my last comment and instead focus only on my comparison of the sprayed amount to the annual rainfall (which I only added so as to put the number into perspective and give it some meaning in the real world).
And you follow it up with a arrogant childish insult: “What is this thread, a bad tutoring session?”
I never said that rainfall increase is the goal!
Please respond to the numbers I addressed. Cause up to now it seems that you are not very proficient in practical engineering, you seem like a theoretical person to me.
Therefore I *will* respond to your last comment by asking you a question about something you probably are proficient in (judging by your fervent defense of this plan and the nature of your other comments):
How much seawater needs to be put in the air in order to change albeido 1%?
-10 ton/s per ship and 1900 ships = 19000 ton/s, as stated by them,
– or 30 kg/s per ship and 1900 ships, as stated by… well, them!
anna
“this non problem that have to be weighted against the damage of cap and trade for the western civilization … You have to support the oracular sayings that do the least damage.”
You made that point earlier, but you play into the hands of the AGW lobby. It will only appear to confirm the groupthink and I can only see C&T as more likely as a result, not less.
There is no waste of money and resources to be justified by bad ideas. Let’s leave that argument for others to make – the day will come when they will stand in the court of public opinion. Didn’t Phil Jones speak on how it feels to play a starring role in that particular arena.
Lance says:
May 15, 2010 at 6:19 am
you said
All the referenced news articles mention that each ship can suck up 10 tons/s. For instance:
http://inhabitat.com/2010/05/10/bill-gates-announces-funding-for-seawater-spraying-cloud-machines/
and repeat it in
Lance says:
May 15, 2010 at 11:19 am
How much seawater needs to be put in the air in order to change albeido 1%?
-10 ton/s per ship and 1900 ships = 19000 ton/s, as stated by them,
– or 30 kg/s per ship and 1900 ships, as stated by… well, them!
Are you really serious?
It is the paper that needs be referenced and has the true proposal of the authors. News articles have no scientific validity. It means that the news writer made the same mistake you and Willis are making in trying to fast read a scientific proposal.
http://rsta.royalsocietypublishing.org/content/366/1882/3989.full
“Yes it gets windy out at sea, and that can cause the exhaust emissions to be blown nearly sideways. The mixing and dispersing plume can get back down to sea level, but the idea is still to get as much of the plume to head upwards, and there really is no othere way to do it. (Ever wondered why land-based industrial complexes have very tall stacks? And therefore you rarely have the experience of smelling their emissions?) ”
I can only repeat this so many times before it gets tedious. Natural processes over the sea will disperse the CCNs throughout the boundary layer. There is no need to shoot them out at high velocity, there is no need to heat them to high temps or to include them in a high temperature gas plume. Nature will do it for you. Any calculations which expect high power consumption because of the problem of getting the particles up to 3000 ft are in error. I can think of no way of saying that clearer.
anna v says: “We are discussing the feasibility of this proposal. The fixed stacks and the boats that already exist do not optimize the distribution as a controlled robotic setup would to cover larger areas. And again you would have the problem of the extra energy/fuel needed to create and spew the salt spray.”
What anna says.
“Here is a photo of the type of thing that goes on around the globe every single day:
http://wwwdelivery.superstock.com/WI/223/1598/PreviewComp/SuperStock_1598R-150374.jpg
There are thousands of similar locations around the globe – so there is already a way to manage distribution using what we have sitting on the ground today. No need to send massive automated vehicles adrift one the open seas.”
Except a) stratocumulus cloud forms over the sea, the sea is where the clouds are, if you want to alter the cloud albedo you have to go to where the clouds are and alter the albedo in situ. b) There is no point in making CCNs where the cloud aren’t. It doesn’t matter if the stacks are amazing, if they shoot particles up to the stratosphere, if they consume megawatts of power in the process, what they do is irrelevant. They do something different from the cloud ships and the experience does not read across. c) The only way you can make a cloud whiter is to have a cloud to start with.
The Salter cloud ships do not make clouds, they alter the albedo of existing clouds by feeding them extra CCNs. Extra CCNs work by stealing water from other droplets in an already-existing cloud. Two droplets have increased albedo compared with one droplet when they share their water and that is how Salter’s ships produce their effects. If you are trying to make clouds from scratch then you are looking at the wrong problem. Satler’s cloud ships are cloud-modifying machines, they are not cloud making machines.
“These machines are designed to move massive volumes of gas high into the air. On volume flow alone, they have the capacity to transport much more CCNs aloft than 10 tonnes per second of brine.”
But they are in the wrong place. The right place is in the large areas of the ocean surface which are almost permanently covered with low level stratocumulus cloud. This cloud has the ideal characteristics to be modified by a vanishingly-small weight of salt, provided that salt is divided into billions of tiny particles. The object of the exercise is not to make the clouds rain, it is to make them whiter. If you make the droplets in a cloud smaller they will be whiter and also less likely to rain. Since most of the new droplets will go back to the sea in short order (20 to 60 hrs IIRC) then the effect will be self-limiting — as soon as the cloud-modifying ship is switched off the cloud whitening effect will start to decay and in three days it will be gone.
“Julian: “few of three thousand foot columns powering up to the inversion layer”
Yes it gets windy out at sea, and that can cause the exhaust emissions to be blown nearly sideways. The mixing and dispersing plume can get back down to sea level, but the idea is still to get as much of the plume to head upwards, and there really is no other way to do it. (Ever wondered why land-based industrial complexes have very tall stacks? And therefore you rarely have the experience of smelling their emissions?) ”
There is no need to shoot upwards the plume of CCNs from Salter’s cloud-modifying ships. As they disperse from the rotors they will mix with the turbulent air (it is necessarily turbulent within the boundary layer because that is the definition of the boundary layer). The boundary layer is a layer of turbulent air next to the surface and is generally two or three thousand feet thick. It is within this layer that the low level clouds which cause cooling when modified are to be found. 30% of the oceans are covered by boundary layer cloud. Boundary layer clouds of the right structure for Salter’s cloud-modifying technique to work on them are rarely found over land. They are, however, frequently found at sea and, because Salter’s cloud-modifying ships are mobile they can be moved to optimum areas to increase the albedo of an area which is ripe for albedo increase. This is the advantage of a mobile CCN-producing device.
“k, so 300 ships are needed (30kg/s each) to get 10 tons/s into the air.
Does that mean that the 1900 ships required to “stop Earth’s temperature from rising” only spray 63 tons/s into the air (0,05% of the annual rain fall in tropical waters), which is supposed to stop AGW? ”
Yes. Once a politician has seen the figures (assuming he bothers to read them, which is not a given, of course, with a scientific proposal ) he will be amazed at how tiny a change of albedo will be enough to counter even the most pessimistic CO2 projection. From there it is a tiny step to wondering if other things (land use change, ocean pollution, soot on ice) might be a large part of putative global warming. He might even look at Palle/s figures of the increase and decrease of Earth’s albedo.
You mention rainfall. It is not about rainfall. Salter’s cloud-modifying ships are not designed to increase rainfall, they are designed to add CCNs to clouds which already exist. These clouds will grow whiter when the added CCNs increase the number of droplets in the cloud. More and smaller droplets are less likely to cause rain and may well make the cloud more persistent, which might be a bad thing over land but over the sea, where the plankton do not need rain and prefer dispersed light, might actually be an advantage.
“If transporting CCNs into the middle atmosphere is such a good idea, what’s wrong with dosing the plumes of the power stations and indutrial complexes we already have all over the place? They are not going to dissapear anytime soon – unless we completely give up our way of life. ”
Salter’s cloud-modifying ships are not designed to transport CCNs to middle altitudes. All they are designed to do is to release CCNs into the boundary layer where natural turbulence will mix them throughout the layer. The layer is about three thousand ft thick and tiny particles like the CCNs produced by Salter’s cloud-modifying ships will be naturally dispersed by turbulence, so there is no need to try to boost the particles at all. This same effect, mixing throughout the layer by natural turbulence, occurs when a wave breaks and releases natural CCNs which are exactly the same sort of CCNs as are released by Salter’s cloud-modifying ships. Salter’s proposal is to add extra CCNs to that process.
“To have a major skeptics blog come out on a witch hunt against it , running after red herrings at that, is not constructive for what should be the future aim of all thinking scientists: avoid cap and trade, wait it out until the PDO convinces people that there is no A in GW.”
My hope is someone will finally do the science on what we are doing to the CCNs in the boundary layer. Noziere’s paper on bacterial surfactants being used to make rain over rain forests is a guide to the direction research should take. If light oil/ surfactant pollution of the ocean surface produces droplets more ready to coalesce and fall out then we are already doing the opposite of what Salter’s ships are supposed to do. By how much has surface pollution lowered the Earth’s albedo? The VOCALS website has some information on cloud physics which is interesting.
“I think this is my last on this.”*
“How much seawater needs to be put in the air in order to change albeido 1%?
-10 ton/s per ship and 1900 ships = 19000 ton/s, as stated by them,
– or 30 kg/s per ship and 1900 ships, as stated by… well, them! ”
The latter! By golly, I think he’s got it! Read Salter’s original paper again, it will all become clear with that revelation in mind. Your problem is that you expect albedo manipulation to involve much power, huge machines, trillions of dollars. Abandon that mindset: think of a two-stage amplifier and imagine that you are only required to input the first, tiny, signal.
JF
*Touch red! (If I’ve got that right. Snap! if I haven’t.) I can only say the same thing so many times….
Julian Flood: “There is no need to shoot them out at high velocity, there is no need to heat them to high temps or to include them in a high temperature gas plume.”
Can we all therefore agree that Salter’s ships are a poor concept.
Julian: “Except a) stratocumulus cloud forms over the sea, … etc.”
Just to be clear, I do understand that the object of the exercise is to whiten clouds by injecting additional CCNs into the atmosphere (more than mother nature appears to be able to achieve on her own).
Now, on locational matters. The coast is a favourable location for many “smokestack” indusries for a variety of reasons. If very close the sea, cooling towers may be avoided, but there will still be a stack for combustion emissions – so there is still a very powerful plume.
But cooling towers are still common place, even for facilities next to the sea. And therefore even more capacity to transport CCNs aloft.
When the wind blows offshore, these locations should be able to get CCNs heading to where you say they need to be. And that would help to avoid the technology leap proposed by Salter.
Certainly, the wind may not always blow offshore for a given location. But there are many such locations around the globe, and that opens the way to a mechanism to handle the optimisation question – CCN dosing could be targetted towards the most favourable sites at any time. We would not then need the technology leap to automated ships.
These industrial facilities are not going to stop any time soon. They offer a free conveyor belt to the high atmosphere for CCNs – one which should be used if it cannot be ruled out for very good reasons. And that includes the no-small matter of a few £bn to build 300 ships.
Julian: “But they [smoke stack industries] are in the wrong place.”
Do you have references to show that your claim is comprehensively established? Is a coastal location with offshore wind of no use whatsoever?
Julian: “it is necessarily turbulent within the boundary layer because that is the definition of the boundary layer)”
In my book (i.e. the engineering text book sitting next to me on my desk) the boundary layer is a region next to a body where friction is important, and where the distribution of flow is affected by boundary shear. Flow is laminar in the boundary layer. Beyond the boundary layer, flow may be laminar or turbulent. For thick boundary layers, there may be a region called the transition.
Julian “You mention rainfall.”
Not me.
Julian: “Salter’s cloud-modifying ships are not designed to transport CCNs to middle altitudes. All they are designed to do is to release CCNs into the boundary layer where natural turbulence will mix them throughout the layer.”
I agree that there will be a lot of mixing going on up there. I’m also happy to accept that it is the existence of CCNs in limited regions that is relevant (i.e. they may not do much good elsewhere). But what I also say is that plumes from industrial complexes looks like a much more effective way of getting more CCNs (more than mother nature appears to be able to manage on her own) into the atmosphere than these ships.
I think your closing comments relate other posters, not me.
I will close by repeating that I think Willis is basically correct in suggesting that Salter’s proposal is a bad idea. I put forward another mechanism to transports CCNs, aloft – but only from the point of view that anything which helps to avoid wasting money on these ships has to be worth prior consideration.
More Bad Numbers
First, my apologies for not posting for a bit on this thread, I’ve been getting ready for the International Conference on Climate Change. I’m in Chicago now, with a few hours free.
There’s another part of the numbers that I haven’t touched on. Stephen Salter quotes their paper above:
This is true but misleading. Clouds currently reflect about 79 W/m2. So rather than a 1.1% increase in global albedo being required, global cloud albedo will need to increase by 4.7%.
And like they say on TV, “but wait … there’s more”. The ships won’t cover the globe. I don’t find coverage figures in the paper, but the press reports say they plan to test this using one ship per 380 square miles.
Is this number reasonable? Well, if you were sailing the good ship “Cloudbrightener” with its Flettner rotors and all, and they worked as claimed, maybe you’d get ten miles per hour out of it on average. That’s 240 miles per day, likely high, but we’ll use that. But it has these whacking great underwater turbines hanging off of it, and with those things sucking up most of the available power, you’d be lucky to get three miles per hour …
Now, their paper says the effect will last for sixty hours, so each ship would be trailing a cloud brightening “flag” 180 miles long, and maybe a couple of miles wide. That’s 360 square miles, so the 380 square mile number seems reasonable. 1,900 ships time 380 square miles/ship is a total of almost three quarters of a million square miles.
That sounds like a lot … but it is only 0.4% of the earth’s surface. Now remember that we need to increase the global cloud albedo by 4.7%. So how much do we need to increase the albedo of 4% of the earth’s surface to give us a global increase of 4.7%?
I’m sure that you can see the problem. No matter how much we increase the albedo of 0.4% of the earth’s surface, even if we could paint it bright white, it wouldn’t be enough to do more than fractionally increase the global albedo. Average cloud albedo globally is about 23%. If we change 0.4% of that to having an albedo of 100%, the average cloud albedo increases by 1%, and we need a 4.7% increase. And of course, according to their figures, they can only increase the albedo by a theoretical maximum of about 10%. (This is slightly offset by doing it only in the tropics, where insolation is stronger.)
Professor Salter’s paper figures it using total energy reflected, which in some ways is easier. They say that if we concentrate on the tropics, in the area where the effect is operating it will increase the energy reflected by about 30 W/m2. Seems high to me, but let’s use that. Total energy reflected by the clouds is about 79 W/m2. To offset a doubling of CO2, we’d have to increase that to 82.7 W/m2. So how much area has to be brightened by 30W/m2 to get the desired amount?
If the percentage of the planet brightened is X, part of the planetary cloud cover is reflecting 79 W/m2, and part is reflecting 109 W/m2. So we get (all values in W/m2):
79 times (1-X) + 109 times X = 82.7
This simplifies to
30 times X = 3.7
Solving this gives us 12% of the globe that would need to be whitened … and as the TV says, “but wait, it’s worse”. Part of the time, conditions will not be favorable for the process to work. After all, you don’t see ships trailing plumes of clouds too often, you have to hunt through stacks of NASA photos to find the effect. Let’s be generous and say it works half the time …
Which means we’d need to brighten the clouds over a quarter of the entire planet.
Now, anna v. said above
Well, I can’t. My first analysis was based on the press reports, because that’s all I could find. However, all of my later objections are based on Salter’s paper itself. I don’t see why he is declining comment, what does he gain by that? I believe in the numbers, and I simply don’t see them pencilling out. The albedo calcs are simply another example of the order-of-magnitude problems with the paper. If he has the numbers that say different, he should bring them out and show them to us. If he is right, I’ll be the first to admit it. But calculations using the figures from the Salter paper say that we will have to brighten more, and likely much more, than 12% of the planet … and you won’t do that with a couple thousand ships.