Steve et al., I have performed some climate model simulations of this idea (holding off on assessing its engineering feasibility).
Let us recall that evaporating water has several possible effects, some of which are: 1. It cools locally by transport latent heat away from the surface 2. It warms somewhere else in the atmosphere by release of latent heat during condensation. 3. If that latent heat condenses higher in the atmosphere, energy has been transported upward, where it might more easily radiate to space. 4. It can diminish the vertical lapse rate (because a moister atmosphere cools less with increasing altitude), so for a constant radiating temperature at the tropopause the surface temperature would warm 5. Water vapor is a greenhouse gas and so an increase would contribute to warming 6. Increased water vapor could form more low clouds, with cooling effects because of high albedo 7. Increased water vapor could form more high clouds, with warming effects because of absorption of outgoing longwave radiation with re-radiation at a lower temperature 8. It can affect boundary layer stability which could have effects on clouds etc. 9. Increased water vapor could affect cloud droplet size which would affect cloud albedo. The importance of these different processes are likely to vary with location. I do not think anybody's understanding of the climate system is good enough to quantify each of these effects in their head without doing detailed calculations. Surprisingly, in the NCAR CAM3 model, converting sensible heat to latent heat was something like 3/4 as efficient at cooling as removing that energy directly to space. My post-doc George Ban-Weiss is working on analyzing and publishing these simulations. Best, Ken ___________________________________________________ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA [email protected]; [email protected] http://dge.stanford.edu/DGE/CIWDGE/labs/caldeiralab +1 650 704 7212; fax: +1 650 462 5968 On Sat, Dec 20, 2008 at 8:02 AM, <[email protected]> wrote: > Alvia & Stephen - One energy efficient arrangement would involve wind pumps > on windy dry coasts. Direct wind is a great way to pump water, especially > when you want to move more water to obtain more evaporation at higher wind > speeds. You don't spray the water into the air, that is not energy > efficient. Instead, you incorporate a vertical water lifting pipe up the > side of a mountain and inside the wind turbine pylon. Then you drop the > water as small droplets into the air and into waterfalls down the side of > the mountain. > > At 100% evaporation efficiency and 70% pump efficiency a 100 meter lift of > 10,000 cubic meters per second requires 10,000 MW. Unfortunately, we need > to figure out what to do with the accumulating tons of salt, on the order of > 10 million cubic metes per year. Or we use more energy at some lower > evaporation efficiency and attempt to disperse the brine in an > environmentally acceptable fashion. Typical 100 meter tall wind turbines > have nominal power ratings of 2 - 4 MW. > > I wonder if we could convince California ski resorts and agribusinesses to > fund a few large scale trials in hopes of getting more snow and rain. The > process is also an ocean desalting project for dry coasts with on-shore > winds. > > Mark E. Capron, PE (Civil Engineer with 'day job' in water, recycled water, > and wastewater) > Oxnard, California > www.PODenergy.org <http://www.podenergy.org/> > > > > -------- Original Message -------- > Subject: [geo] Re: Ace Inventor Thinks He Can Rain in Global Warming > From: Stephen Salter <[email protected]> > Date: Sat, December 20, 2008 3:15 am > To: [email protected] > Cc: [email protected] > > > Hi All > > The evaporation from the Ron Ace spray will certainly remove latent heat > from the atmosphere but exactly the same amount of heat will be returned > when the vapour condenses as rain somewhere else. While it remains as > water vapour it will be adding to amount of the greenhouse gases and so > working in the wrong direction. However if it condenses to form clouds > where there were none before then these will reflect solar energy back > out to space and will be doing what we want. If it adds to the liquid > water content of existing clouds by making the drops in them bigger it > will make them less reflective. Finally the cooling of the lower > atmosphere will make it more stable and will reduce normal evaporation > from the sea downwind of the spray source so reducing both vapour and > cloud cover. One large eddy study, by a top-class atmospheric physicist > who wishes to remain anonymous for fear of ridicule from less able ones, > showed that the stability effect overrode the evaporation one but it > would be useful to compare results. We need to know the balance between > all four effects. > > If anyone knows Ron's email please point him to the five files in > > http://www.see.ed.ac.uk/~shs/Climate%20change/Failed%20rain%20maker/<http://www.see.ed.ac.uk/%7Eshs/Climate%20change/Failed%20rain%20maker/> > > Stephen Salter > > Emeritus Professor of Engineering Design > School of Engineering and Electronics > University of Edinburgh > Mayfield Road > Edinburgh EH9 3JL > Scotland > tel +44 131 650 5704 > fax +44 131 650 5702 > Mobile 07795 203 195 > [email protected] > http://www.see.ed.ac.uk/~shs <http://www.see.ed.ac.uk/%7Eshs> > > > > > Alvia Gaskill wrote: > > I don't think this would make any clouds at all. You can have very > > humid air and no clouds or rain. As far as the evaporation of water > > itself releasing sufficient IR to space, the levels of the water > > injection are too low: 20-200ft. Finally, I don't think the energy > > costs are correctly estimated. It should take a lot more than the > > electricity from a 550MW power plant to simulate the flow of the > > Mississippi River. Am I right or all wet, so to speak? > > > > http://www.physorg.com/news148887530.html > > > > > > > > Inventor's 'refrigeration system' for planet shows promise, but > > scientists are skeptical > > > > December 19th, 2008 in Space & Earth science / Earth Sciences > > > > *Ron Ace says that his breakthrough moments have come at unexpected > > times - while he lay in bed, eased his aging Cadillac across the > > Chesapeake Bay Bridge or steered a tractor around his rustic, > > five-acre property.* > > > > In the seclusion of his Maryland home, Ace has spent three years glued > > to the Internet, studying the Earth's climate cycles and careening > > from one epiphany to another - a 69-year-old loner with the moxie to > > try to solve one of the greatest threats to mankind. > > > > Now, backed by a computer model, the little-known inventor is making > > public a U.S. patent petition for what he calls the most "practical, > > nontoxic, affordable, rapidly achievable" and beneficial way to curb > > global warming and a resulting catastrophic ocean rise. > > > > Spray gigatons of seawater into the air, mainly in the Northern > > Hemisphere, and let Mother Nature do the rest, he says. > > > > The evaporating water, Ace said, would cool the Earth in multiple > > ways: First, the sprayed droplets would transform to water vapor, a > > change that absorbs thermal energy near ground level; then the rising > > vapor would condense into sunlight-reflecting clouds and cooling rain, > > releasing much of the stored energy into space in the form of infrared > > radiation. > > > > McClatchy Newspapers has followed Ace's work for three years and > > obtained a copy of his 2007 patent petition for what he calls "a > > colossal refrigeration system with a 100,000-fold performance > multiplier." > > > > "The Earth has a giant air-conditioning problem," he said. "I'm > > proposing to put a thermostat on the planet." > > > > Although it might sound preposterous, a computer model run by an > > internationally known global warming scientist suggests that Ace's > > giant humidifier might just work. > > > > Kenneth Caldeira, a climate scientist at the Carnegie Institution's > > Department of Global Ecology at Stanford University, roughly simulated > > Ace's idea in recent months on a model that's used extensively by top > > scientists to study global warming. > > > > The simulated evaporation of about one-half inch of additional water > > everywhere in the world produced immediate planetary cooling effects > > that were projected to reach nearly 1 degree Fahrenheit within 20 or > > 30 years, Caldeira said. > > > > "In the computer simulation, evaporating water was almost as effective > > as directly transferring ... energy to space, which was surprising to > > me," he said. > > > > Ace said that the cooling effect would be several times greater if the > > model were refined to spray the same amount of seawater at strategic > > locations. > > > > He proposes to install 1,000 or more devices that spray water 20 to > > 200 feet into the air, depending on conditions, from barren stretches > > of the West African coast, bluffs on deserted Atlantic Ocean isles, > > deserts adjoining the African, South American and Mediterranean coasts > > and other arid or windy sites. To maximize cloud formation, he'd avoid > > the already humid tropics, where most water vapor quickly turns to rain. > > > > "It does seem like evaporating water outside the tropics would be more > > effective," Caldeira said. > > > > The spraying would be targeted mainly at higher, northern latitudes, > > where Ace thinks that air currents known as Ferrel Cells could deliver > > heavy snow to the Arctic, offsetting the melting of the polar icecap. > > > > It stretches the imagination - and perhaps credulity - to suggest that > > a solitary inventor with no government support could solve global > > warming, especially a man who never earned a degree despite studying > > physics for much of a decade at the University of Maryland. > > > > Several scientists who reviewed Ace's patent petition for McClatchy > > reacted with caution to outright derision over its possibilities, but > > some softened their views upon learning of the computer model. > > > > Ace's invention rests on some unconventional theories. > > > > He contends that the planet is 5 to 6 degrees Fahrenheit too hot to > > stop the meltdown from the last ice age 20,000 years ago, not a couple > > of degrees too warm, as government scientists say. He proposes to > > lower the temperature by 3.5 degrees to 4 degrees, leaving a cushion > > to avoid tipping toward another ice age and always retaining the > > option of turning the sprayers down or off, if needed. > > > > He suspects that deforestation is a major cause of global warming, not > > just because trees absorb carbon dioxide, but also because a > > large-leaf tree can wick up and evaporate hundreds of gallons of water > > in a single day. Ace said that the absence of tens of billions of > > trees, destroyed by southward-creeping glaciers thousands of years ago > > and again by man's recent timber cutting, has left the planet > > "slightly dehumidified," reducing cloud cover. > > > > Ace points to recent research that found snow cover is shrinking even > > at below-freezing altitudes on Africa's Mount Kilimanjaro and other > > mountaintops, a change that's attributed to declining snowfall. > > > > It would be relatively easy to design spraying equipment to carry out > > his plan to fill that water vapor deficit, but it would take a major > > international effort to install 1,000 large spraying devices, or > > thousands of smaller ones. If fully deployed, the 15,800 cubic meters > > of sprayed water per second would be equivalent to the flow at the > > mouth of the Mississippi River and would require enough energy to > > power a medium-sized city. > > > > However, spraying only a portion of that amount for a decade would be > > enough to cool the equivalent of current man-made global warming, > > estimated to range up to 0.76 degrees Fahrenheit, Ace said. Such > > cooling, he said, could buy mankind decades of time for more research > > and precision. > > > > Depending on its scale, the water evaporation scheme would cost > > anywhere from hundreds of millions of dollars to billions of dollars a > > year, but Ace said it still would have "a net positive financial > > effect." It would prevent global warming-related damage, he said, and > > the extra rainfall would provide the cheapest way to transport water > > to drought-stricken regions, counteract desert expansions, increase > > natural irrigation for crops and boost the output of hydroelectric > > power plants. > > > > Added rainfall also would reduce atmospheric greenhouse gas levels, > > because cold raindrops carry more carbon dioxide back to the oceans > > than is released when water evaporates, he said. > > > > Caldeira's computer results could surprise many scientists because > > water vapor is a greenhouse gas widely recognized to be more powerful > > than carbon dioxide. The simulation suggests, however, that water > > vapor's cooling effects overwhelm its heat-trapping properties. > > > > Ace has his doubters, partly because he took the patent route rather > > than submitting his idea for scientific peer review. A patent > > certifies that an invention is unique, not that it would work. > > > > Douglas Davis, an atmospheric chemist at Georgia Tech University who's > > known Ace for years, lauded some of his inventions but called his > > global cooling idea "big-time speculation" because so little is known > > about the behavior of water in the atmosphere. > > > > "In the case of the computer models that are used for global warming, > > I know that the hydrological cycle is a critical component of those > > models, and the hydrological cycle is not well understood," Davis > > said, stressing that he's not a climate expert. > > > > David Travis, a University of Wisconsin-Whitewater professor who's > > studied clouds extensively, praised Ace's innovation, but said he's > > "generally opposed to geo-engineering" solutions and can't imagine > > evaporating water on a large enough scale to have a near-term effect. > > > > Caldeira, who plans to submit his computer findings in the spring for > > peer-reviewed publication, is among scientists so concerned about > > sluggish progress in curbing greenhouse gases that they met last year > > to consider geo-engineering options. > > > > "Ideas such as Ron Ace's should be carefully and impartially > > evaluated," Caldeira told McClatchy. "Every brilliant innovation in > > the history of technology looked a little bit loony when first proposed." > > > > Ace's invention looks less loony when compared to some others. NASA > > scientists conceived the multitrillion-dollar idea of orbiting megaton > > mirrors in space to deflect sunlight. Other scientists have proposed > > reflecting solar energy by placing mirrors on thousands of > > high-altitude balloons, by foaming the oceans' surfaces or by filling > > the upper atmosphere with tiny sulfates or inert particles, or by > > adding water droplets to low-level ocean clouds from 1,500 unmanned > boats. > > > > Ace said he thinks that mankind is "headed straight for a disaster." > > > > By focusing solely on solutions that deal with carbon in the > > atmosphere, Ace thinks that mankind won't prevent a "big glacier melt" > > that could lift ocean levels 20 feet and wipe out the world's seaports. > > > > One thing is certain: Ace is dead serious. He's tenaciously compiled > > more than a thousand pages of research, sometimes during all-night > > binges despite a fight with cancer. He said he's invested large sums > > in patenting his global-warming inventions. > > > > Ace said he's created more than 700 inventions, starting with a > > gravity-measuring machine he built in seventh grade to record passes > > of the sun and moon on cloudy days. He's won nearly 70 U.S. and > > foreign patents, but said he's lacked the time and money to submit > > petitions for all but about two dozen of his inventions. None has led > > to big commercial success. > > > > Ace said that his unusual blend of expertise in physics, optics and > > heat transfer has helped him understand the role of light-scattering > > clouds and water's influence on climate. > > > > Maintaining a hermitlike existence during the past three years, he's > > churned out more than half a dozen inventions that could help curb > > global warming, including several that he said would cut energy use. > > > > He often speaks in professorial tones, but can quickly morph into a > > cynic or a feisty debater over the laws of physics, always mindful of > > the role of "the big heater" - the sun. > > > > Ace said that he gradually steeped himself in the science of global > > warming because of "curiosity, nothing more." > > > > "I never saw myself making a dime on it," said Ace, who said he'd > > donate his patent to the U.S. government if he gets one. "It's mostly > > that the data seemed to be incorrect, and I wanted to know what is > right." > > > > ___ > > > > ON THE WEB > > > > The Carnegie Institution's Department of Global Ecology: > > http://dge.stanford.edu/DGE/CIWDGE/CIWDGE.HTML > > > > ___ > > > > /(c) 2008, McClatchy-Tribune Information Services. > > Visit the McClatchy Washington Bureau on the World Wide Web at > > www.mcclatchydc.com/ > > > > > > > > > > -- > > > > > The University of Edinburgh is a charitable body, registered in > Scotland, with registration number SC005336. > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
