Climate change may be liked or disliked, but it is happening beyond human control. Making this process manageable is the very future that scientists and science fiction writers have always dreamed of. And if everything is simple for writers, then science’s path to the goal is thorny and unpredictable, although the result is certainly more valuable. The scientific approach guarantees safety and assumes a high degree of responsibility, which scientists from China have once again convinced us of.
The upgraded X-G500 drone for silver iodide cloud seeding. Image source: Xiamen Tengxi Aviation Technology
In the US and EU, natural experiments with climate are prohibited by law. China has its own atmosphere, but no one has cancelled a balanced approach there either. It was important for scientists not only to understand how the climate in the region chosen for the experiment could change, but also to obtain convincing evidence of a targeted change in climate conditions. Satellite observations, computer modeling, and direct observation of meteorological conditions during the experiments were used to assess the artificial impact on precipitation intensity.
To provoke precipitation, scientists from the China Meteorological Administration (CMA) sprayed silver iodide, a crystalline substance that causes water vapor to crystallize, into clouds. Just one kilogram of the compound, which occupies a volume no larger than a teacup, caused precipitation of more than 70,000 cubic meters—enough to fill 30 Olympic swimming pools.
To induce precipitation, two drones were launched into the sky and carried out four flights. The devices rose to an altitude of 5,500 m and sprayed silver iodide over an area of over 8,000 km², using 125 grams of the substance per flight. Observations showed that as a result of spraying, 78,200 m³ of precipitation fell in the Xinjiang region, where the experiment was conducted, which is 3.8% higher than the average for the past 50 years. Supercomputer modeling gave similar data – 73,800 m³ of additional precipitation (4.3% more), which proves the feasibility of controlling precipitation.
Scientists stress that spraying precipitation is not always effective and is not suitable for all weather conditions. However, precise control of cloud cover and well-thought-out methods of influencing it are key to weather control, which has become possible thanks to satellite monitoring systems and more powerful supercomputers.