Why more countries are turning to weather modification

Countries across the globe are increasingly turning to a decades-old weather modification technique as part of a push to control when and where it rains.

Alongside the U.S. and China, which boasts the world’s largest weather modification program, France, Russia, India and Saudi Arabia are among a growing list of countries to have experimented with cloud seeding.

For many, the embrace of rain-making operations stems from the need to boost water supplies as global demand continues to rise amid the climate crisis.

Others have sought to use cloud seeding to disperse fog at airports, tackle air pollution, reduce hail damage or even to manipulate the weather for major events, such as the 2008 Summer Olympics in Beijing.

Cloud seeding aims to improve a cloud’s ability to produce rain or snow by introducing tiny particles, usually silver iodide. The process is limited both in area and duration and, over time, is estimated to increase local precipitation by 5% to 15%.

The concept is not without controversy, however. Since first taking place in the 1940s, cloud seeding experiments have raised concern over potential environmental and ecological risks and stoked regional security tensions, with countries accusing each other of stealing rain.

Augustus Doricko, CEO of Rainmaker, a California-based cloud seeding company, said there are two dynamics at play that seem to be rekindling people’s interest in the technology — both in the U.S. and across the world.

“One is truly just circumstance, a lot of these countries and regions are suffering from more volatility in climate and precipitation patterns and their water supply, and so it’s leading them through necessity to be more creative than they were in the past,” Doricko told CNBC by telephone.

“Two, and I think this is like the real meat and potatoes of why Rainmaker got started, it’s because in the last few years there have been some fundamental breakthroughs in how to do measurements and attribution of cloud seeding effects.”

Despite an 80-year legacy, Doricko said interest in cloud seeding “really fell off” in the 1970s and 1980s because it had been difficult to accurately measure how much precipitation derived from cloud seeding deployments.

Recent technological improvements now make it possible to verify the success of these deployments in real time, Doricko said.

The company, which says it intends to arrest the aridification of the American West, has grown rapidly in recent months, from just 19 employees at the beginning of 2025 to 120 today, a trend that appears to underscore the booming interest in cloud seeding.

Yet, despite its name, Doricko said the company’s cloud seeding projects are mostly designed to make it snow.

“I misnamed the company it turns out, and ‘Snowmaker’ probably would have been more apt. It doesn’t sound as good for what it’s worth,” Doricko said.

He added: “I think that the most important thing for Rainmaker to do this season is just to make unambiguous evidence of manmade snow — and do it so often that it is undeniably a viable and scalable technology.”

Other U.S.-based cloud seeding companies include Weather Modification Inc. in North Dakota and North American Weather Consultants in Utah, although some U.S. states, such as Florida and Tennessee, have banned weather modification activities.

There are two key reasons for why more countries are embracing cloud seeding operations, according to Frank McDonough, a research scientist at the Nevada-based Desert Research Institute (DRI).

Firstly, the scientific research and validation efforts that have been conducted on cloud seeding projects around the world over the past several decades “have provided enough data and cost-benefit analysis for stakeholders to use this tool with confidence,” McDonough told CNBC by email.

“The other concept of why more countries may be embracing cloud seeding technologies is that it’s currently one of the only options to enhance increasingly stressed localized water resources or help mitigate regional air pollution by using Earth’s natural atmospheric systems as a viable water source,” McDonough said.

Most other technologies rely upon water resources that are directly pulled from a watershed’s surface of groundwater, McDonough said, citing ski resorts using stored water to operate their winter snow-making equipment as one example.

“Cloud seeding can actually add new water resources to the system. Having extra resources to put into the ‘watershed bank’ for following year’s snowmaking needs is why stakeholders continue to fund these projects,” he added.

In terms of state-level support, China has reportedly backed its weather modification program with $2 billion between 2014 and 2021, while Saudi Arabia spent $256 million in 2022 to support the first year of its regional cloud seeding program.

Authorities in Iran reportedly sprayed clouds with chemicals over the Urmia lake basin late last year, seeking to boost rainfall to combat the country’s worst drought in decades.

Such projects are not always successful, however. Together with the Delhi government, a team at the Indian Institute of Technology (IIT) Kanpur recently reported mixed results following a cloud seeding trial to tackle air pollution in India’s capital city.

The IIT said in a statement at the time that its attempt was “not completely successful” due to a lack of moisture in the air, before adding that there had been a measurable reduction in particulate matter following the experiment.

Diana Francis, head of the Environmental and Geophysical Sciences lab at Khalifa University in Abu Dhabi, said cloud seeding can “modestly enhance” precipitation in the right conditions.

“But it is incremental, not transformative, and works best as part of a broader water and air-quality strategy,” Francis told CNBC by email.

Cloud seeding operations might typically cost between $1 to $10 per hectare-meter of additional water, Francis said, noting that while this remains highly variable, it works out to be much cheaper than desalination.

There are also other key caveats to consider, such as a strong dependence on cloud microphysics (given cloud seeding only works on existing clouds), problems with attribution and potential geopolitical and legal issues regarding downwind impacts, Francis said.

Studies have shown no significant impact on either human health or the environment from previous silver iodide cloud seeding projects, according to the World Meteorological Organization, while further investigation is needed to assess downwind effects.

The U.N. weather agency has also acknowledged that significant challenges in public, social and local acceptance of rain-making operations remain widely evident.