Faced with its worst drought in living memory, China is turning to cloud seeding to bring rain to the parched reservoirs along the Yangtze River – Asia’s longest water-supplying river. water to hundreds of millions of people.
The summer has been marked by record-breaking heat waves in the United States and parts of Europe – and it’s no different in China.
The National Metrology Center issued a “red alert” weather warning last week with temperatures in a handful of regions expected to exceed 40C (104F), state-run newspaper China Daily reports. Temperatures in China have remained high for more than 63 days and they are not expected to drop anytime soon.
With these cooking temperatures comes dryness. Rainfall would be down 45% from average in China and water in the main body of the Yangtze – as well as two large lakes in its basin, Dongting and Poyang – fell to its lowest level on record.
Local authorities have been advised to spray fields with a “water retention agent” to prevent water from evaporating or seeping in. Meanwhile, factories in parts of the country were forced to close last week due to growing demand for air conditioning and water shortages to generate hydroelectricity.
Many provinces are also seeking to combat drought with the help of cloud seeding operations, according to the China Daily. Some provinces have opted to use cloud-seeding aircraft, while others have used surface-to-air cloud-seeding missiles.
Cloud seeding techniques can vary, but the process generally involves “seeding” the sky with silver iodide or other crystalline particles that have a structure similar to ice in clouds. Water droplets gather around the ice crystal in the atmosphere, like seeds for rain droplets, increasing the chance of precipitation.
This is far from the only time China has indulged in weather modification like this. Last year, Beijing was shown to be using cloud seeding technology to ensure Chinese Communist centenary celebrations would be blessed with blue skies and sunshine. They pulled off a similar feat to ensure the 2008 Summer Olympics weren’t hampered by rain.
Not all scientists are convinced that cloud seeding is an effective way to simulate rain. Some studies have shown that cloud seeding has little or no impact on the amount of precipitation in a given season, while others have found that it can have a significant impact on precipitation. .
Nevertheless, the need to combat drought is evident. The coming weeks are a key time for the fall harvest of rice, grain and other crops in the Yangtze basin. As Reuters reported, high temperatures and desperately dry soils have affected 457,500 hectares (1,130,507 acres) of land and have already cost China $400 million in economic damage.
If allowed to persist, this drought could have repercussions for the entire global economy.