How One Climate Scientist Combats Threats and Misinformation from Chemtrail Conspiracists

Harvard geoengineering researcher David Keith explains when to feed the trolls and when not to.

Last spring, Harvard climate scientist David Keith announced that he and a colleague intended to proceed with small-scale geoengineering experiments in the real world (see "Harvard scientists moving ahead on plans for atmospheric geoengineering experiments").

The basic idea behind the technology they're studying, known as solar geoengineering, is that spraying certain particles into the stratosphere could reflect enough heat back into space to offset some level of global warming. But the move from lab research to atmospheric experiments has sparked controversy....