Cloud Seeding: International Development and Concerns

Cloud seeding is one method of reversing the negative effects of climate change. (Wikimedia Commons)

Cloud seeding, a form of weather modification proven to help increase regional precipitation on small scales, may be a sign of hope that the effects of climate change can be addressed more quickly than previously thought.  On an international scale, however, regulatory, social, and environmental complications arise. 

Cloud seeding involves the release of silver iodide particles or other aerosols into clouds to increase precipitation.  The concept originated in 1947, and in its early forms cloud seeding was principally a strategy to produce smokescreens during the Vietnam War.  

The collapse of the United States’ Project Skywater only about a decade after the end of the Vietnam War is a clear example of the complex concerns associated with cloud seeding (and weather modification in general).  The program aimed to harness atmospheric moisture through cloud seeding in order to “explore, develop and determine the feasibility of applying the technology of weather modification to meet the Nation’s increasing demand for clean water.” However, after about ten years of testing, the project essentially shut down. In the face of Cold War tensions, members of the U.S. public expressed fears that the technology might be weaponized; others were concerned about its unknown long-term environmental effects. Others simply felt uncomfortable with the idea of people being able to control the weather. 

In the 21st century, relatively small-scale cloud seeding experimentation has expanded in the United States again, while globally, countries’ approaches to weather modification technologies now vary widely.  Some regard weather modification as a worthwhile risk.  In late summer 2024, for instance, the Malaysian state of Penang resorted to cloud seeding operations after its two principal dams fell to dangerously low capacities.  Between 2020 and 2024, several midwestern U.S. states began to accelerate their efforts to improve their weather modification technology in order to combat drought.  Russia and Thailand have effectively employed cloud seeding to subdue wildfires.  Other countries approach weather modification research and application more openly. For example, in 2019, Chinese authorities attempted to use cloud seeding to ensure clear weather for a military parade celebrating the 70th anniversary of the People’s Republic.

The rise of cloud seeding in both the public and private sectors has not outstripped global citizens’ concerns, however, and though international regulations have been structured to address some of those concerns, the large scale on which they must be synchronized and enforced presents difficulties.  Article 5 of the UN Convention on the Law of the Non-Navigational Uses of International Watercourses, for example, states that nations may “use transboundary watercourses for cloud seeding,” but there is no doubt that conflicts will arise regardless.  After all, the effects of cloud seeding efforts targeted at a certain region are unlikely to remain confined to that region, and may be economically and environmentally harmful to surrounding areas. There is evidence that the particles used in cloud seeding may contribute to widespread air pollution, soil erosion, and flooding, among other issues.  

Other apprehensions center around the public perception of cloud seeding.  Practically, the technique “can only boost existing storms, not generate entirely new ones” and it “requires very specific…conditions to work.” Scientists and policymakers worry that citizens might mistake cloud seeding as the human capacity to have total control over the weather and as the final solution to climate problems. In reality, it is an imperfect way of counteracting deep damage to the global environment.