==Delivery== 
 I believe Andrew Lockley proposed the use of long-barrel artillery, firing the projectiles with aerosols using a compressed gas (air, nitrogen, ...) Perhaps it can be mentioned ? 
 See https://www.mail-archive.com/geoengineering@googlegroups.com/msg00664.html 
 and http://www.ce-conference.org/design-practical-hardware-climate-engineering