Rainmakers: Will drones make cloud seeding more effective?

On 23 August, Cooper Freeman had no idea clouds above his head were being filled with a silver compound in order to cause rainfall.

Neither did thousands of other residents in Homer, Alaska, who later discovered San Francisco start-up Rainmaker conducted an experiment in that region using cloud-seeding technology.

The company claims it produced 19 million US gallons of water in the sky in three hours.

This approach to weather modification, now more than 80-years-old, involves using planes and drones…