EVERY CHEMTRAIL HAS A SILVER LINING : 100 YEARS OF UNINTENTIONAL SOLAR RADIATION MANAGEMENT RESEARCH
They don't make chemtrails like they used to. Paranoid skywatchers who quail at the sight of water vapor contrails must quake to see the spectacularly substantial smoke curtain Col. Billy Mitchell drew during his famed 1923 Naval bombing demonstration. The fleet of doomed surplus battleships and prizes of war disappeared behind a
THESCOPEXEXPERIMENT THAT TIME FORGOT
thick veil of titanium oxychloride smoke formed by the moist air hydrolysis of ~10 kilograms of titanium tetrachloride vapor sprayed behind a World War I biplane. Not for long, though - a squadron of Curtis bombers sank the dreadnought and three other ships shortly thereafter. Mass produced TiCl4 became cheaply available in the 1920's as bright titanium oxide pigments began to displace toxic lead carbonate in white paint.
This WWII training film shows the1923 smoke curtain experiment more fully
By 1942, specialized spray tanks allowed the controlled the dispersion of such liquids from aircraft , but while Roger Revelle and Charles Keeling proposed bright particle dispersions to raise ocean albedo in their 1965 White House report on how to respond to warming from AGW, aerosols were not discussed. It apparently takes about a kilogram of TiCl4 to generate a hectare of curtain area
Just as this century old film may hold data of use in designing bright aerosol pigment experiments like SCOPEX, it suggests that aerosol curtains might slow surface melting of Arctic sea ice and Greenland snow exposed to the heat of the midnight sun.
Gavin Schmidt and other Goddard Center climatologists may have some skin in this game: besides inventing liquid fuel rockets, Dr Goddard patented the wing-tank sprayer seen in the 1942 film:
The rise of battery powered drones could change the game by lowering the cost, and carbon footprint of cloud curtain generation. Before the internet, skywriting with cheap aerosols was the last word in mass advertising, and its low cost per view prefigured the economic attractions of stratospheric geoengineering. The sky still makes a bully billboard, and swarms of Amazon delivery drones could become an entry level technology for pixilated future skies driven by AI microclimate algorithms to simultaneously display ads and adjust sunlight to the weather on the ground below.
Drones that deliver sixpacks of beer could just as well carry white skywriting ink, to become platforms for made-to-measure shade and microclimate delivery for outdoor events and gatherings of all sorts, anywhere from Singapore to the Greenland ice cap. Who knows- if anybody can figure out how to morph the externalities of smoke generation into a business model for Arctic albedo conservation, it's Jeff Bezos.
( Full disclosure: I once coauthored a Nature Daedalus column with David Evans.)
