The internet is filled with claims that “aviation based-contrails and ship tracks are used to geoengineer the sky.” The following list, which I have compiled over the last year, is a compilation of referenced quotes of scientists conspiring to use commercial aviation or ship tracks to geoengineer the climate:
Scientists saying creepy stuff:
- “Use commuter aircraft fuels doped with aerosol generators” 
- On the possibility of weather modification by aircraft contrail 
- Weather Modification by Carbon Dust Absorption of Solar Energy 
- “dissolved or suspended in their jet fuel and later burned with the fuel to create seeding aerosol, or (2) injected into the hot engine exhaust, which should vaporize the seeding material, allowing it to condense as aerosol in the jet contrail” 
- “Options for dispersing gases from planes include the addition of sulfur to the fuel, which would release the aerosol through the exhaust system of the plane, or the attachment of a nozzle to release the sulfur from its own tank within the plane, which would be the better option.” 
- “The particles may be seeded by dispersal from seeding aircraft; one exemplary technique may be via the jet fuel as suggested by prior work regarding the metallic particles. Once the tiny particles have been dispersed into the atmosphere, the particles may remain in suspension for up to one year.” 
- “regulation to ban bunker fuel for ships should be relaxed while encouraging continued use of bunker fuel where the resulting aerosol emissions might be beneficial.” 
- “Establish the positive and negative net forcing from contrails, and encourage flight paths of commercial airplanes to reduce positive or increase negative net forcing. The ban on polar flights, lifted recently, should be reintroduced”
- “Develop and test the deployment of suitably reflective particles, of such materials as TiO2, as alternative or supplement to sulphate aerosol.” Prepare for large scale deployment. 
- “Finance the development of, and deployment capability for, marine cloud brightening, with a view to deployment on a large scale in spring 2013″ 
- “Suitable chemicals need to be identified/confirmed, with stock-piling of these cloud seeding chemicals. Aircraft need to be kitted out to spray these chemicals.“ 
- Prepare the supply and logistics for spraying aerosol precursor in large quantities, preferably into the lower stratosphere, for deployment by next March or April (2013) 
H2SO4 (SULFURIC ACID) FROM AVIATION MAY BE HIGHER TODAY THAN WHAT WOULD BE REQUIRED FOR A GEOENGINEERING REGIME IN 2020By Oscar Escobar Tuseday, November 26, 2013
Quite recently a very short twitter conversation between David Biello (Scientific American), Oliver Morton and Tim Cross (the latter two from the Economist), chatting about Cross’s latest article “Stopping a scorcher”  netted this VERY IMPORTANT assertion by Tim Cross:
Nov 23, 2013: “@dbiello piece (by me!) says it "SOUNDS LIKE a technocratic fever dream". Big difference; b/c geo-engineering actually entirely plausible”
This is in my view a very important fact that should be planted front and center at the beginning of any geoengineering debate or article. Not only that… there should also be a statement of fact in reference to the “unintended” (ongoing) global geoengineering experiment that is being conducted by the aviation industry through its emissions, its sulfur emission to be more specific.
In an earlier article by MIT Tech Review , we learn about the plausibility of GE technologies through the studies of Harvard's physics professor and entrepreneur at Carbon Engineering, David Keith, leading proponent of geoengineering technologies. We also learned that, according to Keith, the initial required amount of sulfuric acid (H2SO4) for a geoengineering Solar Radiation Management (SRM) regime is quite small:
"According to Keith’s calculations, if operations were begun in 2020, it would take 25,000 metric tons of sulfuric acid to cut global warming in half after one year. Once under way, the injection of sulfuric acid would proceed continuously. By 2040, 11 or so jets delivering roughly 250,000 metric tons of it each year, at an annual cost of $700 million, would be required to compensate for the increased warming caused by rising levels of carbon dioxide. By 2070, he estimates, the program would need to be injecting a bit more than a million tons per year using a fleet of a hundred aircraft."Given that by 1990 global aviation’s “annual contribution to the atmospheric sulfur budget by aircraft of 2.E7 kg H2SO4.” , and that by 2010 Aviation emissions could had been up 110% compared to 1990 levels  it is safe to assume that by the year 2013, H2SO4 by aircraft emissions is already at the level that would be required by 2020 for a geoengineering regime. In other words: geoengineering is way ahead of schedule!
Also giving all the warnings about the side effects of geoengineering by SRM on the hydrological cycle i.e. drought and flooding; and the ecosystems in land and the ocean, such as this one by Edward Teller:
“Consider what might happen if we start by using a stratospheric aerosol to ameliorate global heating; even if it succeeds, it would not be long before we face the additional problem of ocean acidification”. It is not at all shocking that we are already there ... in all counts... today! So, to the byline:
“Intentionally engineering Earth’s atmosphere to offset rising temperatures could be far more doable than you imagine, says David Keith. But is it a good idea?”I would think the answer is clearly… NO! It is not a good idea. Specially in the case of SRM. Then, it could also be said that one of the most relevant questions about geoengineering by SRM is… how do we stop?
“So perhaps those in the GE community who are genuinely opposed to geoengineering should revise their premises and call for research into GE with the purpose of ending this ‘unintended', but failed and still ongoing experiment.”
 Stopping a scorcher The controversy over manipulating climate change Nov 23rd 2013 – The Economist http://www.economist.com/news/books-and-arts/21590347-controversy-over-manipulating-climate-change-stopping-scorcher
 A Cheap and Easy Plan to Stop Global Warming Intentionally engineering Earth’s atmosphere to offset rising temperatures could be far more doable than you imagine, says David Keith. But is it a good idea? February 8, 2013 - By David Rotman http://www.technologyreview.com/featuredstory/511016/a-cheap-and-easy-plan-to-stop-global-warming/
 Soot and Sulfuric Acid from Aircraft: Is There Enough to Cause Detrimental Environmental E-kCTSs? Pueschel, R. F.; Strawa, A. W.; Ferry, G. V.; Howard, S. D.; Verma, S. (NASA Ames Research Center; Moffett Field, CA, United States); Publication Date: Jan 01, 1998 Document ID: 20070003482
“Applying the H2SO4 emission index to the 1990 fuel use by the worlds commercial fleets of 1.3E11 kg, a conversion efficiency of 30% of 500 ppmm fuel-S would have led to an annual contribution to the atmospheric sulfur budget by aircraft of 2.E7 kg H2SO4.” http://nix.nasa.gov/search.jsp?R=20070003482&qs=N%3D4294966753%2B4294724624%26No%3D10
 Aviation emissions up 110% since 1990 Nov 19 2010 - Aviation Environment Federation. http://www.aef.org.uk/?p=1151
 Quote of the Day: James Lovelock on Geoengineering & The "Practice of Planetary Medicine" September 1, 2008 - By Kimberley Mok – treehugger http://www.treehugger.com/culture/quote-of-the-day-james-lovelock-on-geoengineering-the-practice-of-planetary-medicine.html
 20 Facts About Ocean Acidification November 2012 - U.S. OCB Sub-Committee on Ocean Acidification http://www.whoi.edu/fileserver.do?id=165564&pt=2&p=150429
Updates: December 17, 2013
"However, increasing ship fuel sulfur content in the open ocean would violate existing international treaties, could cause detrimental side-effects, and could be classified as geoengineering."Climate and air quality trade-offs in altering ship fuel sulfur content I. Partanen et al doi:10.5194/acp-13-11925-2013 http://www.atmos-chem-phys.net/13/12059/2013/acp-13-12059-2013.html [PDF: acp-13-12059-2013]
Video On the “Colbert Report” from Monday December 9, 2013
David Keith "A Case For Climate Engineering" author David Keith explains his proposal to use geoengineering as a means of slowing climate change. (06:25) http://www.colbertnation.com/the-colbert-report-videos/431083/december-09-2013/david-keith
December 1, 2013 What Is Geoengineering and Why Is It Considered a Climate Change Solution? April 2010, By David Biello - Scientific American http://www.scientificamerican.com/article.cfm?id=geoengineering-and-climate-change
Starting then Stopping Geoengineering Could Dangerously Accelerate Climate Change November 27, 2013 By Henry Gass and ClimateWire - Scientific American http://www.scientificamerican.com/article.cfm?id=starting-then-stopping-geoengineering-could-accelerate-climate-change&page=2
The Seas Could Turn to Sulfur January 11, 2010 By Peter L. Ward - big think
"So when we heated the poles to the point that there is no longer – or already in a very sluggish ocean circulation, the ocean is going anoxic, they lose their oxygen. They only keep oxygenated now because of this vigorous mixing. Well, even when you have oxygen in the atmosphere and contact with the surface, once you slow down any circulation, that whole basin can lose this oxygen. The Black Sea is the same case. It’s sits under a 21% oxygen atmosphere, and yet the Black Sea, except for the top several meters, in anoxic. It’s black because it’s producing a lot of sulfur-producing bacteria and there’s very nasty gasses that are produced.
We now think the big mass extinctions were caused by global anoxia. The oceans themselves so sluggish that the hydrogen sulfide bacteria are produced in huge areas of the ocean bottom bubbles up to the surface and starts killing things; rotten egg killing. It would be extremely nasty. Hydrogen Sulfide poisoning is a horrible death. Two hundred hydrogen sulfide molecules among a million air molecules is enough to kill a human. I mean, just breathing in 200 of those little things amid all the million you’re got in oxygen and boom, you’re down, horribly down.
So, this is a really nasty poison and it was certainly present in past oceans during these short-term global warming events. That’s why it’s really spooky what we’re doing now."
Check out ship tracks and aviation contrails on ClimateViewer 3D daily: