Sunday, August 1

Make it rain: US states embrace ‘cloud seeding’ to try to beat drought | Environment


With three-quarters of the western US afflicted by a seemingly incessant drought, several states are increasingly adopting a drastic intervention: modifying the weather to stimulate more rainfall.

Latest reports from the US Drought Monitor. have provided a sobering reading, with 40% of the United States west of the continental divide classified as “exceptional drought,” the most severe of the four levels of drought. This is only marginally below 47% in January, a record in the monitor’s 20-year history, and barring the arrival of a barrage of late-winter storms it will almost guarantee a severely dry year for the western states.

“We haven’t had a lot of rain or snow in winter, which is concerning as we expect to make a big impact on the drought,” said Brian Fuchs, a climatologist at the National Center for Drought Mitigation. “It looks like it is going to be a very tough year. We are probably seeing an increase in fire hazards, water restrictions, and also impacts on ecosystems, such as small rivers and streams and the wildlife that lives there. “

The stresses of the drought, on the supplies of water for drinking and to supply the vast agricultural systems of the west, have caused eight states to look at to a form of weather modification called cloud seeding to avoid the worst.

Cloud seeding involves using airplanes or drones to add small particles of silver iodide, which have an ice-like structure, to clouds. The water droplets gather around the particles, modifying the structure of the clouds and increasing the possibility of precipitation.

“Since drought remains a major concern, cloud seeding is a recommended technology for Wyoming under our drought contingency plan,” said Julie Gondzar, project manager for the state water development office. “It’s an inexpensive way to help add water to our watersheds, in small incremental amounts over long periods of time.”

Cloud seeding experiments have been carried out since the 1940s, but until recently little certainty the method had some positive impact. But research last year managed to locate snowfall that “unambiguously” came from cloud seeding, and Gondzar said officials in Wyoming and elsewhere have “concluded that cloud seeding works and is an effective way to help in drought-stricken areas, with no impacts. negative environmental “.

Others are now looking to join, including the “four corner” states – Utah, Arizona, Colorado and New Mexico – that have been devastated by the most extreme version of the latest drought. “We are very hopeful of significant funding this year to achieve enough for the entire state in the future,” said Rick Ledbetter, supervisor of the Roosevelt soil and water district in New Mexico who has piloted the seeding clouds. . “I think there will be no choice in the future but to look at the weather modification.”

Experts who have studied cloud seeding point out that it is not a panacea, since it does not solve the systemic causes of drought and can be difficult to implement: only certain clouds in certain climatic conditions can be seeded with nascent rain and there is no guarantee of so be it. it will break a drought even if it succeeds.

“I don’t think cloud seeding solves the problem, but it can help,” said Katja Friedrich, a researcher at the University of Colorado who has studied the issue. “It must be part of a larger water plan that involves conserving water efficiently, we cannot focus on just one thing. There is also the question of whether he will be able to do it in a changing climate: he needs cold temperatures and once it gets too hot he cannot do cloud seeding.

While states are trying to formulate a response to the growing threat of drought, advocates warn that the poorest people and people of color are more likely to suffer from a water-constrained future. Miguel Hernandez, from the non-profit organization Civic Committee of the Valley in Southern California’s Imperial Valley, he said the drought has brought ongoing problems for Latino farmworkers, some of whom have to resort to using irrigation canals to cook water or brush their teeth.

“Getting them clean water is a priority,” he said. “We also have problems with water diverted to metropolitan areas, leaving us with little or no water in our region. The drought causes a lot of different problems here. “

The current drought has been building up since an exceptionally hot summer last year, but the last 20 years can collectively be viewed as a “mega-drought“In the western United States, Fuchs said. Scientists have pointed to the climate crisis as a key cause.

“There has been very little relief and this could well be a precursor to what to expect for the west in the future,” Fuchs said. “It’s a little scary to think that way.”


www.theguardian.com

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