"Researchers find that a program to fight climate change by injecting aerosols into the atmosphere from high-altitude aircraft would be possible, but unreasonably costly and unlikely to remain secret."

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"LOS ANGELES-Scientists have proposed a new way to tackle climate change by spraying sun-dimming chemicals into the Earth's atmosphere, according to a study published on other day. Scientists at Harvard and Yale universities have proposed using a technique known as Stratospheric Aerosol Injection (SAI), which they believe could cut the rate of global warming by half, according to a paper published in the journal Environmental Research Letters."

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German article on CE.

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Smith, W.; Wagner, G. (2018): Stratospheric aerosol injection tactics and costs in the first 15 years of deployment. In: Environ. Res. Lett. 13 (12), S. 124001. DOI: 10.1088/1748-9326/aae98d.

"We review the capabilities and costs of various lofting methods intended to deliver sulfates into the lower stratosphere. We lay out a future solar geoengineering deployment scenario of halving the increase in anthropogenic radiative forcing beginning 15 years hence, by deploying material to altitudes as high as ~20 km. After surveying an exhaustive list of potential deployment techniques, we settle upon an aircraft-based delivery system. Unlike the one prior comprehensive study on the topic (McClellan et al 2012 Environ. Res. Lett. 7 034019), we conclude that no existing aircraft design—even with extensive modifications—can reasonably fulfill this mission."

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