Cloud seeding is not a once-and-done treatment. An unknown in the equation is whether cloud seeding will create an imbalance for nature to figure out. The argument goes that synthetically producing more precipitation than nature intended might keep the environment from balancing naturally.
Is human made rain the way to help the increasing droughts?
by Dawn Hammon
https://inhabitat.com/is-human-made-rain-the-way-to-help-the-increasing-droughts/
As the world faces record temperatures and ongoing issues with drought, scientists look towards solutions for not only saving water, but creating it. We have the science and the capabilities to create rain. So the question is whether cloud seeding is worth the time, money and effort.
What is cloud seeding?
Think of it as planting a garden in the sky. Cloud seeding is not a new idea. Originally developed by Nobel prize-winning chemist Irving Langmuir and his deputy Vincent J. Schaefer in the 1940s, the process involves stimulating the moisture inside clouds to enhance precipitation. It’s done by injecting particles, gasses or chemicals into existing clouds.
Scientists have done this through everything ranging from an airplane spraying the cloud to ground-launched flares aimed to the sky. Although the material and injection methods vary, they all act similarly inside the cloud.
Clouds are full of teeny tiny droplets of moisture that aren’t heavy enough to fall to the ground. When stimulated by the chemicals, most commonly silver iodide, those droplets are able to create an anchor and absorb the surrounding droplets. When they become heavy enough, in as little as 20 to 30 minutes, the drops then fall from the sky as rain or snow. Cloud seeding is credited with causing moisture to fall, either by initiating rain or by increasing the amount of precipitation that falls.
Is cloud seeding being used?
Yes, around the world. Australia, China, India, Israel, South Africa and Thailand all have programs. Over the years, around 50 countries have tried it in some capacity. In the United States: California, Idaho, Nevada, Utah, Colorado, Wyoming, Texas and North Dakota all practice some form of cloud seeding. Because the science relies on the right types of clouds in the right weather conditions, the opportunities to plant the seeds is limited to when storms roll through. That means cloud seeding during the winter in the hopes of improving water conditions for agriculture and other consumption during the summer.
Does cloud seeding work?
It’s a great debate. Some researchers show precipitation increases from 3% to 15%, while other researchers dispute those claims, saying it’s impossible to isolate cloud seeding as the contributing factor. In other words, we just don’t know decisively if it’s helping, but many in the scientific community, as well as agricultural and drought-stricken regions, are optimistic.
What are the advantages of cloud seeding?
The obvious advantage is the production of precipitation. With more research, we can discover whether it’s an effective means of increasing snowpack in the mountains and rainfall in wet regions. Many regions are already labeling their efforts a success, even if other scientists may not definitively agree. For example, organizers of a five-year program in the Snowy Mountains of New South Wales, Australia claim snowfall increased by 14%, while a similar program in Wyoming reported a 15% increase. These figures offer a promising option in battling drought.
What are the disadvantages of cloud seeding?
Using airplanes to deliver the chemicals means adding carbon emissions to the atmosphere while we attempt to battle the water crisis. However, drones are a more environmentally-friendly option, and just as viable. Plus, rockets can be shot from the ground surface without the use of a plane.
However, cloud seeding is not a once-and-done treatment. An unknown in the equation is whether cloud seeding will create an imbalance for nature to figure out. The argument goes that synthetically producing more precipitation than nature intended might keep the environment from balancing naturally.
What’s the future of cloud seeding?
At this point, it’s definitely part of the ongoing conversation. The efforts are spreading across the western U.S. and around the world as it gains traction as a viable contributor in fighting drought conditions. Even proponents don’t pretend cloud seeding is a solution to the world’s drought problems, but it could be part of the answer. The drought issue is huge and will require a robust solution from a combination of angles.
While producing more precipitation is an important aspect, we have to look at the entire water cycle. Remember elementary school science class when we learned the same water continues to cycle from the sky to the ground and back to the sky? That precipitation falls to the Earth, where it is absorbed and stored in the soil. Additional water ends up in the streams, lakes, rivers and oceans. Through evaporation and transpiration that water heads back into the sky where condensation occurs.
However, when temperatures are too hot, the cycle breaks down, leaving the moisture in the sky instead of in the soil and waterways. So in addition to cloud seeding as one piece of the pie, policies and people need to still focus on water conservation. In the end, the answer will be a combination of solutions, at every level of government and across borders.
China to forge ahead with weather modification service
ENGLISH.GOV.CN
The State Council
The People’s Republic of Chine
http://english.www.gov.cn/policies/latestreleases/202012/02/content_WS5fc76218c6d0f7257694125e.html
The State Council issued a circular on Dec 2, laying out measures for the quality development of weather modification.
According to the document, China will have a developed weather modification system by 2025, with breakthroughs in fundamental research and R&D in key technologies, steady improvements in modernization and refined services, distinct enhancement in comprehensive prevention against safety risks, and optimization in systems and policy environment.
The total area of artificial rainfall (snowfall) operation will reach beyond 5.5 million square kilometers, and for hail suppression it should go beyond 580,000 square kilometers.
By 2035, China’s weather modification should arrive at a worldwide advanced level in terms of operation, technologies, and services, the circular said.
Weather modification should intensify its service backup in the following key fields: estimation for disasters such as drought and hail, and related zoning work in agricultural production areas; normalized working plans for regions in need of ecological protection and restoration; and major emergency responses to deal with events such as forest or grassland fires, and unusual high temperatures or droughts.
世界で研究が進む「人工的な雨」は、干ばつを救えるか
by 高野優海
https://ideasforgood.jp/2022/10/05/cloud-seeding/
今、世界中で「人工的な雨」の研究が進んでいることをご存知だろうか。
2022年の夏は、日本を含め世界中で記録的な猛暑が広がった。それに伴い、山火事や干ばつなどの自然災害も、世界各地で深刻化している。そんな状況を受け、人工的に雨や雪をつくり出す技術──「クラウド・シーディング」の研究が各国で進んでいるのだ。
クラウド・シーディングとは、「雲の種まき」という直訳のとおり、ヘリコプターなどを使ってヨウ化銀や液体窒素などの化学物質を雲の中に散布し、それを種として氷の結晶を発達させ、雨や雪を降らせる技術のこと。ある程度発達した雨雲に対して使用する手法であるため、雲がないところに雨を降らせることはできないのが特徴だ。
一般的には干ばつなど水不足の解消、山火事の消火、猛暑の抑制などの目的で使われるが、特定の日時を好天にするために事前に雨を降らせるといった用途で使われることもある。世界気象機関（WMO）の2017年の調査によると、米国、中国、インド、オーストラリア、南アフリカなど、すでに50カ国以上が何らかの形でクラウド・シーディングに挑戦しているという。
オーストラリアでは、2005年〜2009年のクラウド・シーディングプロジェクトにより、同国南東部のプロジェクトエリア全体の降雨量が14%増加したという研究論文が発表された。
中国では、2019年1月に新疆ウイグル自治区西部でクラウド・シーディングを実施し、農作物の70%が雹害（ひょうがい）を避けることができたと中国国営の新華社通信が報じた。
さらに中国政府は、2020年に大規模な気候制御計画を発表し、2025年までに国土の約56%、日本の面積の約15倍に相当するエリアでクラウド・シーディングを用いた人工的な降雨や降雪を行うことを目指すとしている。
このようにクラウド・シーディングは、気候変動への対策として各国で開発が急がれており、実際に成果が出ているという報告もある。しかし地球環境や生態系に与える影響はまだ十分には解明されておらず、自然界のバランスを崩すことにつながるのでは、という議論も根強く存在する。
国際ルールも未整備であるため、国家間の水資源争奪を生むのでは、という懸念の声もある。日経新聞によると、中国が気象制御計画を発表した際、インドなどの現地メディアでは「大きな脅威」「国際的な紛争につながる」と反発の声が挙がったほか、2018年にはイランの軍事組織幹部が、クラウド・シーディングに取り組むイスラエルを「雨雲を盗んでいる」と非難したという。
クラウド・シーディングをはじめとした気象制御技術は、その影響の解明やルールの整備、市民への十分な説明など、透明性の確保が今後の課題だと言えるだろう。
今や気候変動は、私たちの身近なところにまで迫ってきている。私たち市民個人も、こうした技術の動向を注視し、自分なりの意見を持つ姿勢を大事にしていきたい。