This process involves using aircraft or ground based generators to release tiny salt particles, such as silver or potassium iodide, into clouds.
These particles enhance the condensation of water vapor, facilitating the formation of larger water droplets. As these droplets gather, they can transform into snowflakes high up in the clouds. When these snowflakes fall towards the ground and pass through warmer air, they melt and eventually fall as rain.
This technique effectively increases rainfall from existing clouds.
Cloud seeding requires several conditions to be met before it can be seen as an affordable way to increase water supplies.
● Cloud seeding is only useful in specific places and under certain weather conditions. It needs existing clouds to work, as it cannot create rain from thin air or nothing.
● It is most effective during wet years, helping to increase water storage in dams.
● Not every cloud can be seeded. For effective cloud seeding, the clouds need to be thick enough and have a temperature between -10 and -12 degrees Celsius.
These suitable conditions for cloud seeding are often found in mountainous regions. This presents a challenge for much of Australia’s mainland, including Perth, which is mostly flat and not ideal for cloud seeding. The most successful cloud seeding efforts have taken place in Tasmania, particularly in its mountainous western areas.
Since its introduction in the 1940s, the advanced weather modification method known as cloud seeding has been used worldwide, including in places like the UAE, China, and the United States.
It’s often used by governments to tackle droughts. Cloud seeding has also played roles in major events: it helped clear skies of pollution for the 2008 Beijing Olympics, pushed away radioactive clouds heading towards Moscow after the Chernobyl nuclear accident, and was used to disrupt enemy movements during the Vietnam War. However, using weather modification in warfare has now been prohibited by the U.N.
For many years, the UAE, a country with limited rainfall, has significantly invested in cloud seeding. This includes offering permanent residency to experts in the field and supporting research to improve cloud seeding techniques.
However, the effectiveness of cloud seeding is still up for debate. In 2003, the U.S. National Research Council stated that there was not yet any convincing scientific evidence to prove its effectiveness. A significant study in 2020 did show that cloud seeding can be effective, but researchers also pointed out that it has its limitations.
Meteorological officials in the UAE claim that their cloud seeding efforts can boost rainfall by 10-30%. In California, authorities estimate their program can increase rain by 5-10%. The Desert Research Institute in Nevada reports that their cloud seeding can raise seasonal precipitation by about 10%. The World Meteorological Organization stated in 2019 that cloud seeding results can vary widely, from almost no impact to a 20% increase.
The success of these efforts largely depends on specific weather conditions like wind and cloud temperatures.
Contrails Vs Chem-trails
Experts believe cloud seeding is often misunderstood by the public, who may overestimate its effects. While it can increase rainfall, many other natural and human-made factors are more significant in causing floods.
There are several misconceptions about cloud seeding, including the belief that it creates “chem-trails” — white streaks or lines in the sky similar to cloud formations. The Desert Research Institute explains that these are actually “jet contrails,” similar to the visible breath you see in cold air, which are produced by aircraft and have nothing to do with cloud seeding.
● Jet contrails are the white lines you see in the sky following an airplane. They happen when the moist air from the plane’s engines hits the colder air high up in the sky, turning the moisture into ice crystals that form the white lines.
● Moist air comes from airplane engines because the fuel used in these engines contains hydrogen. When fuel burns in the engine, hydrogen combines with oxygen from the air to form water vapor as a byproduct. This water vapor is part of the exhaust gases released by the engines, contributing to the moist air that forms contrails when it encounters the cold, high-altitude atmosphere.
However, there are reasons to be cautious about cloud seeding.
Critics believe that seeding clouds in one area might just take rain away from another area, as it causes clouds to release their rain sooner than they naturally would. For instance, Iran has long accused its neighboring countries of “stealing their rain” through cloud seeding.
There are also health worries related to the chemicals used in cloud seeding. For example, silver iodide is commonly used and might be harmful to animals, although some argue that it is safe.
In an article for the Bulletin of Atomic Scientists, Laura Kuhl, a public policy professor at Northeastern University, suggests that cloud seeding might cause more problems than it solves. She points out that the uncertainties and limited effectiveness of the technique could lead to false hope in technology, which might distract from addressing underlying issues such as unsustainable water usage and unequal water distribution. This report was further discussed by Time online, a US-based media platform, highlighting the ongoing debate surrounding the impacts and ethics of cloud seeding.
● Unsustainable water usage means using water more quickly than nature can replace it. Unequal water distribution means that water is not shared fairly, so some people have a lot while others have very little.
Dubai’s Flooding Crisis
The recent severe flooding in Dubai may largely be due to the country’s lack of proper drainage systems, which are not built to handle heavy rain. Experts also point out that a key factor behind such extreme weather is climate change. As the air gets warmer, it can hold more moisture, leading to more intense rain and flooding in certain regions.
Roslyn Prinsley, who leads disaster solutions at the Australian National University Institute for Climate, Energy and Disaster Solutions, told TIME that it’s highly unlikely for cloud seeding to cause flooding, labeling such ideas as “conspiracy theories.”
Prinsley emphasized that the real concern should be human activities that release greenhouse gases into the atmosphere, which contribute to global warming and increasingly severe weather, rather than cloud seeding.
Extreme weather worldwide is largely driven by climate change on top of natural weather patterns, explains Roslyn Prinsley. She notes that while cloud seeding is used to coax (or encourage) rain from stubborn clouds, the intense rainfall and severe flooding in Dubai were more likely caused by thunderstorms enhanced by climate change. This pattern of heavy rain is increasingly common around the globe, according to Prinsley.
