Rainmaker drones seeded clouds over Alaska; residents unaware

On 23 August, Cooper Freeman had no idea clouds above his head were being filled with a silver compound to cause rainfall, according to the BBC. Thousands of other residents in Homer, Alaska, later discovered that San Francisco start-up Rainmaker had conducted an experiment in the region using cloud-seeding technology, the BBC reported.

Rainmaker claims it produced 19 million US gallons of water in the sky in three hours. The BBC reported that this amount equates to around 0.01 inch of rain across 100 square miles.

Cloud seeding is more than 80 years old, according to the BBC. It involves using planes and drones to disperse compounds such as silver iodide into clouds to form ice crystals, which grow large enough to fall as rain or snow depending on temperatures below. The BBC reported the technology needs ideal climate environments, such as mountainous or cold regions like Alaska, and that seeding sessions have to wait for clouds to form.

Freeman, the Alaska director of the Center for Biological Diversity, said he was concerned Homer residents were not widely alerted to the experiments. He said it does not appear there was any downstream monitoring to verify that the silver iodide did not impact the environment. He also said having a company come in to do the seeding "isn't going to solve our water woes" and "feels like a distraction" from solving urgent issues related to water conservation, according to the BBC.

Augustus Doricko, Rainmaker's founder and CEO, said the company releases the silver at 20 grams per flight, distributed across thousands of square kilometres. He said the resulting increase in concentration on the ground is in parts per quadrillion, which he said is below the threshold laid out by the US Food and Drug Administration (FDA).

The BBC reported that more than 50 countries are developing programmes to modify the weather and that a surge of start-ups are developing systems to create rain. UN Secretary-General António Guterres said in July that "our world is using freshwater faster than it can be replenished", the BBC reported. The BBC said this echoes reports that the past five years have led to the driest period for global rivers in more than three decades.