This is so profoundly stupid it's unbelievable, except that of course it's totally believable:
"Sounds crazy"? It is crazy:
Scientists are proposing an ingenious but as-yet-unproven way to tackle climate change: spraying sun-dimming chemicals into the Earth's atmosphere. The research by scientists at Harvard and Yale universities, published in the journal Environmental Research Letters, proposes using a technique known as stratospheric aerosol injection, which they say could cut the rate of global warming in half.The technique would involve spraying large amounts of sulfate particles into the Earth's lower stratosphere at altitudes as high as 12 miles. The scientists propose delivering the sulfates with specially designed high-altitude aircraft, balloons or large naval-style guns.
Despite the technology being undeveloped and with no existing aircraft suitable for adaptation, the researchers say that "developing a new, purpose-built tanker with substantial payload capabilities would neither be technologically difficult nor prohibitively expensive." They estimate the total cost of launching a hypothetical system in 15 years' time at around $3.5 billion, with running costs of $2.25 billion a year over a 15-year period. The report does, however, acknowledge that the technique is purely hypothetical.