China successfully used cloud seeding to control the weather, reduce pollution, and improve the air quality index of its capital city of Beijing ahead of a major political event in July, according to a study by scientists at Tsinghua University, as reported by South China Morning Post.
Cloud-seeding is a weather modification technique that involves introducing chemicals to clouds, like small particles of silver iodide. This causes water droplets to cluster around them, increasing the likelihood of rainfall.
The government undertook an extensive, two-hour cloud-seeding operation over suburban Beijing and some adjacent areas on June 30, the day before the Communist Party marked its centenary with major celebrations including tens of thousands of people at a ceremony in Tiananmen Square.
Residents in neighboring mountain regions reported witnessing rockets blasted into the sky carrying silver iodine into the sky to stimulate rainfall, according to the paper published in the peer-reviewed Environmental Science journal and led by environmental science professor, Wang Can.
The resulting artificial rain reduced the level of the air pollutant PM2.5 by more than two-thirds and changed the air quality by the World Health Organization standards, from “moderate” to “good”, the researchers said. Since “artificial rain was the only disruptive event in this period,” it was unlikely that the drop in pollution was due to natural causes.
China’s history with weather modification
This isn’t the first time China has undertaken cloud seeding. In fact, the government has spent billions of dollars to manipulate the weather, and has employed the technology to manipulate the weather before major gatherings, such as the 2008 Beijing Olympics.
Back in 2020, China’s State Council announced that by 2025, the country will have a “developed weather modification system” covering more than 1.35 billion acres (5.5 million sq km) with artificial rainfall and one of about 143 million acres (580,000 sq km) with hail suppression.
The most recent known application of the technology adds to a body of scientific evidence around the technique’s success. Other countries have invested in cloud seeding technology as well due to the effects of climate change worsening in recent years; however, there are still valid questions over the degree of its effectiveness, and scientists are still debating about whether manipulating the weather in one area could disturb weather systems elsewhere.
However, Beijing is reportedly well aware of the risks and limitations of the technology, according to Xu Xiaofeng, a former deputy director at the China Meteorological Administration.
“Weather modification is not only a scientific problem but also a social engineering project closely related to [a country’s] interests, environment, and responsibilities,” Xu wrote in a paper, which appears in the Chinese journal Advances in Meteorological Science and Technology. “To deal with these problems, we need to have new laws, regulations or international treaties,” he added.
Could the technology see a wide adaptation?
The technology is also used in the United States, with one of the prime examples being Idaho Power, a private utility serving more than half a million customers in southern Idaho and eastern Oregon. For nearly two decades, Idaho Power has used cloud seeding to supplement its hydroelectric power production, according to The Independent.
And as the effects of climate change worsen with the world smashing global temperature records year after year, countries are also considering other techniques to draw rainfall. This summer, the United Arab Emirates turned to drone technology to turn the tide on the searing heat, and used drones that fly into clouds where they then discharge electricity to kickstart rain in the city of Dubai, which reaches heats of up to 120°F (48°C). This reduces temperatures and provides much-needed water resources.