Is Cloud Seeding Worth the Bet?


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Pilots from Climate Modification, Inc., put together the cloud seeding plane with seeding flares. (Credit score: Derek Blestrud, Idaho Energy Firm)

“Make mud, not conflict.” That was the slogan of the American 54th Climate Reconnaissance Squad, the primary army drive to interact in climate warfare.

All through the Vietnam Conflict, they flew 2,602 missions, releasing silver iodide, a compound that seeded clouds and exacerbated monsoons—or so the considering went. Dubbed “Operation Popeye”, this wet warfare would final from 1966-72, till banned beneath the 1977 Enmod Treaty on climate warfare. Popeye wasn’t the one try and weaponize seasonal occasions, however it was probably the most notorious. There was additionally, for instance, an “exercise” aiming to make the Hồ Chí Minh path muddier, named “Commando Lava”. The issue with infamy, nevertheless, is that the themes of it not often stay as much as the legend.

Being that Vietnam was an lively struggle zone with shifting concentrating on areas, it was troublesome to get correct knowledge on how efficient cloud-seeding actually was.


A cloud-Seeding package mounted on a WC-130. (Photograph Credit score: USAF)

However College of Wyoming scientists, the Nationwide Science Basis, and a handful of Idahoan pilots are dashing in to seek out out simply how a lot management we actually have over the climate. Working in live performance with the Idaho Energy Firm, this scientific workforce will gather knowledge in Idaho’s Payette Mountains to feed right into a supercomputer and simulate the consequences of cloud seeding. Armed with three Doppler radars, an array of floor sensors and plane-mounted probes, operation SNOWIE (Seeded and Pure Orographic Wintertime Clouds—the Idaho Experiment) will function a data-collection mission extra advanced than any previous it.

At this time, a profitable software of cloud seeding is electrical energy era. Over, say, a mountain vary that collects a 300-inch snowpack yearly, even a 5 % bump in snowfall might add as much as a worthwhile achieve in electrical energy output for hydroelectric crops downstream. It’s one in every of a number of burgeoning efforts by energy corporations trying to make betting much less dangerous with extra knowledge.

The best way to Play Rain God

Like personal Johnny, cloud seeding has long-since left the struggle. However for the 56 countries that now have seeding operations, up from 42 in 2011, the know-how has undergone a character cut up, settling into two camps: hygroscopic seeding and glaciogenic seeding.


(Credit score: Wikimedia Commons)

With hygroscopic seeding, water-drawing particles—typically some variation of salt, resembling calcium chloride—are launched from planes flying at low altitudes. It really works greatest in “heat clouds” with a considerable quantity of liquid water, often pushed by oceanic climate patterns. The particles function nuclei whereupon droplets condense and swell till the cloud grows heavy with rain.

Glaciogenic cloud-seeding then again, is a frigid affair.

“The idea behind glaciogenic seeding,” says College of Wyoming atmospheric scientist Jeff French, is that “the silver iodide acts as what’s referred to as an ice nucleus.” Ice accumulates across the particles at barely hotter temperature than regular, and within the unfavourable eight to 25 diploma Celsius vary, French says “ice could be very environment friendly at rising quickly.” Thus, ice crystallized onto silver iodide—or potassium chloride, dry ice, or liquid propane—begets extra of the identical, till supercooled clouds are laden with snow.

Climate Is Actually A Efficiency Artwork

Of the 2, hygroscopic seeding is usually employed to struggle fires and improve crop yield. And in most of the nations the place it’s utilized, it’s employed with a cowboyish gusto. In China, artillery shells full of seeding materials have been praised for the clear climate through the 2008 Olympics. In Thailand, the Royal Rainmakers, began by the late King Bhumibol Adulyadej, are hailed because the prop plane-armed crusaders of the nation’s farmers.

The info, nevertheless, is much less variety. “We did fairly an in depth research there,” says David Reynolds, a cloud-seeding skilled with the NOAA, “I don’t assume we actually ever decided that was efficient or not. South Africa in all probability has the strongest evidence of accelerating rainfall from seeding.”

That doesn’t quantity to a lot. On the entire, whereas most revealed analysis on hygroscopic seeding acknowledges some impact, the outcomes are often inconsistent and marginal. Probably the most detailed survey on cloud-seeding science, a 2003 report, concluded that “there nonetheless is not any convincing scientific proof of the efficacy of intentional climate modification efforts.”

Ditto for glaciogenic seeding, which has come to be a widely-employed software to suppress hail. The method encourages extra vigorous nucleation of ice crystals, which is assumed to yield smaller, extra dispersed hail, however once more outcomes are spotty.

Measuring A Shift Amongst Variances

“That isn't to say there isn't any outcome, it’s simply to say that they might not present a outcome,” says French. Though the literature ranges from no impact to, on the excessive finish of the standard predictions, a 15 % improve in precipitation, the consensus locally is that if there's an impact, the impact might be someplace on the order of 5 %, based on French. That’s a minute sign.

The perfect technique for measuring the impact can be to match the precipitation between randomly-assigned seeding and management areas. However a change of 5 % can simply be “buried inside the pure variability of precipitation,” in response to Reynolds.


Snow gauges, operated by the Nationwide Middle for Atmospheric Analysis, measure how a lot snow falls. (Credit score: Scot Landolt, NCAR)

Thus, our greatest technique for analyzing whether or not or not it really works is to collect as a lot cloud sample knowledge as attainable and simulate the consequences of seeding. And in simply such a study, revealed in 2013, researchers in Wyoming confirmed that glaciogenic cloud seeding might truly improve snowfall. That’s excellent news for hydroelectric corporations with cash driving on these outcomes, in addition to findings from the SNOWIE venture.

The majority of the undertaking will happen in the air aboard an plane offered by Idaho Energy, from which researchers will launch silver iodide into the environment. Then, from the College of Wyoming’s twin turbo-prop plane, referred to as King Air, researchers will take measurements to know the results of including silver iodide to clouds. Lastly, the info will probably be processed on the NCAR-Wyoming Supercomputing Middle, which can simulate clouds and snowfall created naturally and by way of cloud seeding.

The findings of SNOWIE gained’t apply to each equally mountainous space with supercooled clouds—there are just too many variables at play. They definitely shall be of restricted relevance to rain-making seeding initiatives.

Nonetheless, past serving as push to review a subject that has develop into an anathema to public analysis sponsors because the ‘80s—and one bringing higher knowledge with extra technologically superior devices than ever earlier than—SNOWIE is emblematic of a shift in mindset: We'd like knowledge earlier than praising these 20th century precipitation gods.