The Rainmakers

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Being as vast as it is, Earth has quite a diverse geography. Each part is endowed with certain attributes; some are mountainous, others are hilly, some are cold while others are hot; some are wet, others are dry.

For those living in dry areas, it can be quite arduous, since water is the essence of life. However, not all places are naturally dry, increasingly, places where it used to rain a lot have been suffering from prolonged draughts.

Humans—being who they are—try to solve these issues as best as they can. Even though centuries ago it would have been unimaginable that humans can have a hand in changing the weather, armed with scientific knowledge, researchers can find ways to solve climate problems through weather modification processes.

So, how does one make it rain when the clouds just will not let go their cargo? The answer is “cloud seeding”.

Cloud seeding has been used worldwide. For example, it has been used for 10 years in the UAE, but this does not mean to say that it has not been around for longer.

The principles of cloud seeding were discovered by the American chemist Vincent Schaefer in 1946. Since then, it has developed into a method that can help in various situations.

Some countries use it when they suffer from drought, others to improve agricultural environments; for example, to make clouds release their hale before they reach a crop area to avoid damage to the crops. Artificial rain can also alleviate the negative impact of air pollution; in China, haze can be terrible, because of all the exhaust fumes, whereas in Malaysia and Singapore, haze is caused by forest fires in Indonesia. Using cloud seeding, governments try to improve the quality of the air, since usually the air clears after it rains.

Cloud seeding is carried out by either a plane flying into the clouds and depositing chemicals to make the rain fall, or by firing rockets with the chemicals into the clouds. The chemical most widely used is silver iodide, which is sprayed from airplanes onto the clouds. Water is attracted to this chemical and tend to bond with it, creating a big enough drop to fall. Dry ice is sometimes used as a substitute in the same process.

However, not all scientists agree on the after effects cloud seeding causes. Some believe that the use of silver iodide can be harmful, while others do not support this idea. Those who worry, see that if cloud seeding is continuously used over a certain area for long periods of time, eventually there will be a build-up of silver on the ground which is then absorbed into the ecosystem. This will eventually negatively affect humans.

Interested to see how it is done? Check out the following video.

References
scientificamerican.com
bbc.com
humantouchofchemistry.com

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