- Published
On 23 August, Cooper Freeman had no idea clouds above his head were being filled with a silver compound in order to cause rainfall.
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clouds → publish → 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.
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Rainmaker → do → technology
The company claims it produced 19 million US gallons of water in the sky in three hours.
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it → claim → hours
This approach to weather modification, now more than 80-years-old, involves using planes and drones to disperse compounds such as silver iodide into clouds to form ice crystals.
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approach → involve → crystals
Those crystals eventually become large enough to fall as rain or snow, depending on the temperatures below.
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crystals → become → temperatures
Essentially, cloud seeding speeds up the natural process of water vapor condensing inside of clouds.
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seeding → speed → clouds
Gravity then pulls those crystals to the ground.
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Gravity → pull → ground
The technology, though, needs ideal climate environments, such as mountainous or cold regions such as Alaska.
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technology → need → Alaska
Freeman, the Alaska director of the Center for Biological Diversity, isn't just concerned Homer residents weren't widely alerted to these experiments.
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residents → concern → experiments
He's sceptical about what was shot into the clouds, and questions how safe it was for both residents and their habitat.
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it → shoot → residents
"It doesn't appear that there was any downstream monitoring to verify that this silver iodide didn't impact the environment," he says.
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he → appear → environment
Freeman adds, "Having a company come in to do this seeding isn't going to solve our water woes, and it feels like a distraction from solving the urgent issues related to water conservation."
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it → add → conservation
Concerns are mounting about the challenges surrounding water security.
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Concerns → mount → security
United Nations Secretary-General António Guterres said in July "our world is using freshwater faster than it can be replenished, external", which echoes reports noting how the past five years have led to the driest period for global rivers, external in more than three decades.
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years → say → decades
Cloud-seeding technology may be a drop in the bucket, as it doesn't create rainstorms.
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it → seed → rainstorms
For example, Rainmaker's 19 million gallons equates to around 0.01 inch of rain across 100 square miles.
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gallons → equate → miles
Nevertheless, more than 50 countries, external are developing programmes to modify the weather and a surge of start-ups are developing systems to create rain.
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surge → develop → rain
As well developed and promising as this innovative field has become, these businesses continue to face thorny questions on safety and efficacy, leading to novel approaches with both finding the right material to spray into clouds and how they do it.
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they → become → it
Augustus Doricko, the founder and CEO of Rainmaker, is quick to answer any questions on the consequences of how his company uses the silver iodide compound.
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company → answer → compound
It's clear he's been asked about chemical safety many times.
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he → ask → safety
He says Rainmaker releases this form of silver at 20 grams per flight, distributed across thousands of square kilometres.
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Rainmaker → say → kilometres
"The resultant increase in concentration on the ground is in the parts per quadrillion, way below the threshold laid out by the FDA [Food and Drug Administration] on what is allowable."
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what → lay → FDA
Rainmaker's flights use drones to soar into clouds because without clouds, "we can't do anything," he says, pointing to one of the key limits of cloud-seeding processes.
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he → use → processes
Cloud-seeding sessions have to wait for clouds to form to try to coax them into precipitation.
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clouds → seed → precipitation
Their drones are outfitted with silver iodide flairs, and when lit the burning atomizes the water particles into a small enough size so they can stay suspended in the freezing cloud for hours, eventually turning into crystals and later rain.
Rainmaker operates in states such as Idaho, Utah, Colorado and areas of the Middle East such as Jordan.
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Rainmaker → outfit → Jordan
Doricko says, "Jordan residents often only have water for hours per week from their utility because of how scarce water is, and it's a privilege to try to help this storied region."
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it → say → region
Cloud seeding's roots began in 1946 when researchers from the General Electric Research Laboratory used dry ice as the first seeding agent.
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researchers → begin → agent
A year later, silver iodide was found to be more effective than dry ice, which quickly turns into useless gas.
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which → find → gas
While seeding agents caused more rainfall, they didn't move the needle much.
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they → cause → needle
In fact, sobering statistics point to how patchy this technology can be in what it pours on the ground.
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it → point → ground
"With the right conditions, cloud seeding squeeze out about an extra five to 10% of precipitation," says Jon Meyer, an assistant state climatologist with the Utah Climate Center.
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Meyer → squeeze → Center
What was encouraging, though, for the cloud-seeding sector was a landmark 2017 study that found how silver iodide worked as expected, one of the first reports to observe cloud seeding in action using radar and precipitation gauges.
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iodide → seed → radar
In the past several years, Meyer has been encouraged to see more companies such as Rainmaker bring innovation to an old industry.
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companies → encourage → industry
"Drones [such as Rainmaker's products] present this new avenue," says Meyer, "and they offer a more targeted nature to these clouds we hope will be responsive.
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we → present → clouds
"
What is sprayed into clouds may also be undergoing a major shift.
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sprayed → spray → shift
Recast Systems in San Francisco is experimenting with a type of protein made from amino acids found in the soil, says CEO Olivia Li.
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Li → experiment → soil
While still undergoing tests at Texas A&M University, this new seeding agent moves Recast away from silver iodide as the go-to compound.
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agent → undergo → compound
"It's safe, biodegradable and nucleates ice at a higher efficiency than silver iodide," says Li, whose company currently uses silver iodide to seed clouds in several US states.
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company → nucleate → states
Meyer is optimistic this technology's trajectory will only continue to rise.
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trajectory → continue → ?
"We're going to see more demand for these services as so many regions are experiencing water demand," he says, "and they're going to be looking for ways to help bridge that gap."
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they → go → gap
The Aporia
