The cost to construct a Stratospheric Shield with a pumping capacity of 100,000 tons a year of sulfur dioxide would be roughly $24 million, including transportation and assembly. Annual operating costs would run approximately $10 million. The system would use only technologies and materials that already exist—although some improvements may be needed to existing atomizer technology in order to achieve wide sprays of nanometer-scale sulfur dioxide particles and to prevent the particles from coalescing into larger droplets. Even if these cost estimates are off by a factor of 10 (and we think that is unlikely), this work appears to remove cost as an obstacle to cooling an overheated planet by technological means.
1/20th Scale Testing of Aerosols to the Stratosphere was funded but the actual test called off
British researchers supported by the U.K. government were attempt to pump water a kilometer into the air using little more than a helium balloon and a rubber hose. The experiment, which was to take place at a military airfield along England’s east coast, was meant as a test of a proposed geoengineering technique for offsetting the warming effects of greenhouse gases. If the balloon and hose could handle the water’s weight and pressure, similar pipes rising 20 kilometers could pump tons of reflective aerosols into the stratosphere.
In May 2012 this first field test was cancelled altogether in agreement of all project partners. Dr. Matthew Watson, the project´s lead scientist, named two reasons for the cancellation: First, involved scientists had submitted patents for similar technology, presenting a potentially significant conflict of interest. In addition to that, concerns about the lack of government regulation of such geoengineering projects were raised Although the field testing was cancelled, the project panel decided to continue the lab-based elements of the project.
Iron dust fertilization of the ocean live test
American entrepreneur named Russ George dumped 120 tons of iron dust off the hull of a rented fishing boat; the plan was to create an algae bloom that would sequester carbon and thereby combat climate change.
His actions created an algae bloom larger than the area half of the size of Massachusetts (satellites measured a 10,000 square kilometer bloom) that attracted a huge array of aquatic life, including whales that could be “counted by the score.”
Mr. George, whose iron dumping exploit did more than test a thesis about ocean fertilization: it also tested the waters for future geoengineering experiments. And judging by the muted response so far, the results of Mr. George’s test are clear: geoengineers proceed, caution be damned.
Some ocean trials reported positive results. IronEx II reported conversion of 1,000 kilograms (2,200 lb) to carbonaceous biomass equivalent to one hundred full-grown redwoods within two weeks. Eifex recorded fixation ratios of nearly 300,000 to 1.
Current estimates of the amount of iron required to restore all the lost plankton and sequester 3 gigatons per year of CO2 range widely, from approximately 2 hundred thousand tons per year to over 4 million tons per year. The latter scenario involves 16 supertanker loads of iron and a projected cost of approximately €20 billion ($27 billion)
I think the mass of it was 100 to 500 grams per square meter. and about half of that might of sank. Some studies show that algae get to about 600 grams per square meter before the population collapses.
So if we assume 100 grams sank per square meter, then about 1 megaton CO2 might have been sequestered with the 120 ton dumping.
Need to get more diatoms to grow for more sinking of the bloom.
What exactly actually happens with the bloom depends upon the makeup of what actually ends up growing. They did take a lot of water samples and there are robotic bouys for monitoring it. (paid for by Canadian government).
There were two UN conventions that say that this type of thing should not be done but they could not actually enforce it.
The Indian tribe paid to boost the food for salmon to try to increase salmon stocks.