In recent years, China has expanded its national weather modification programme to exploit climatic resources and adapt to climate change. The unprecedented scale of China's weather modification programmes has raised concerns over potential environmental impacts, including transboundary impacts. This article analyzes the domestic governance of weather modification in China and the extent to which this legal framework satisfies China's obligations under customary international law to minimize risks of significant transboundary harm. We find that existing arrangements do not satisfy procedural obligations under customary international law; nor do they adequately address the risks of environmental impacts associated with the increased use of weather modification. Procedures for transboundary environmental impact assessment (EIA) and engagement with regional neighbours are needed for China to comply with international law and promote stability in the region.

The use of technological and chemical means aiming to achieve favorable weather conditions or reduce the risk of weather extremes is known as Weather Modification (WM). The United States of America, the People’s Republic of China, Thailand, the United Arab Emirates, and Europe have employed WM in an effort to prevent hurricanes and storms, control precipitations, mitigate deforestation and drought, and enhance agriculture. Recently, the use of WM has been expanded toward decreasing air pollution and creating favorable weather conditions for major political and athletic events. The increasing significance and use of WM call for consideration upon its positive and negative effects on human health, close collaboration among health experts and WM decision makers, and relevant public health emergency contingency planning.