Cloudburst, flash floods, death and destruction - every year, one part of India or another faces such a natural calamity.
Now, the Chief Minister of Telangana has floated a conspiracy theory. K. Chandrashekar Rao recently said, "There is this new phenomenon called cloudburst. People say there is some conspiracy, we don't know how far that is true, that people from other countries are deliberately doing cloudburst in our country at certain locations. In the past they did it near Kashmir, at Ladakh-Leh, then in Uttarakhand and now we are getting some reports that they are doing it in the Godavari region."
Could this be true? Could an enemy nation be engineering cloudbursts and flash floods in India?
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The most widely-known weather modification technique to artificially increase rainfall is cloud seeding. Clouds are made up of water droplets and ice crystals. These are formed when water vapour in the atmosphere condenses around tiny dust or salt particles.
Without these small particles, or nuclei, drops wouldn't form, and rain won't fall. Cloud seeding increases the number of nuclei in clouds so that water vapour gets more particles to form drops or snowflakes.
There are three major methods of cloud seeding. The first technique is static seeding in which a chemical, like silver iodide, is inserted into clouds via ground-based generators or diffused from planes.
The second technique is dynamic seeding which uses up to 100 times more ice crystals than static seeding. This is a complex procedure with over 10 stages, and an error in any stage can ruin the entire process.
The third technique is hygroscopic in which salts are inserted into the lower portions of clouds through flares or explosives. Experts say this method is promising but requires further research.
Cloud seeding is mostly popular as a civilian technology, being used to increase rainfall in dry areas, or to combat effects of climate change. But could it be used as a weapon too?
Just a couple of decades after scientists developed the concept of cloud seeding, America deployed it as a weapon in Vietnam. This operation in the 1960s is the first confirmed use of meteorological warfare.
The US Air Force conducted cloud seeding operations to hinder the movement of North Vietnamese troops, and also suppress anti-aircraft missile fire at US planes. The operation led to flooding of communication lines, but some officials said that the results were not dramatic.
The weaponisation of weather by America caused global alarm, and in 1978, the Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification went into force.
Does this mean that India has nothing to fear from weather warfare? The answer may not be so easy.
Cloud seeding is actually a major strategy employed by India's biggest competitor China. Weather modification has been institutionalised in China since Mao Zedong's rule. Beijing has used cloud seeding to drain clouds of moisture and ensure clear skies at major events. This was done ahead of the 2008 Olympics opening ceremony, and before the 70th anniversary of the People's Republic of China festivities.
China's mega cloud seeding projects employ around 35,000 people, and now Beijing is planning a massive expansion. China reportedly wants to cover an area more than one-and-a-half times India's size with cloud seeded rain. This is causing major worry in India, as rainfall patterns in the region may get affected, and even the Brahmaputra river's flow may be impacted.
But what about actually causing cloudbursts on Indian territory? Could a hostile nation be behind the floods in Telangana, as the Chief Minister claimed?
This is unlikely, because of two major reasons. Firstly, a cloud seeding plane from a foreign country would have to fly undetected in Indian airspace to be able to inject chemicals in clouds. Secondly, this would only work on clouds which already have high moisture content, as cloud seeding doesn't create water in clouds, only helps it fall in greater quantities.
According to the Indian Meteorological Department, cloudburst is defined as unexpected rainfall exceeding 10cm per hour over a 20-30 sq km region.
However, research has thrown up a mixed bag when it comes to the effeCtiveness of cloud seeding. In USA's Nevada, long-term projects increased snowpack by around 10%. A 5-year project in Australia's New South Wales increased snowfall by around 14%. However, another study in USA's Wyoming said that cloud seeding would increase snowpack only by around 1.5%.
With climate change wreaking havoc, extreme weather events in India are becoming more common. In such a situation, it would be better if the Telangana Chief Minister either provides proof of his serious claim, or takes steps to reduce the impact of floods and other calamities on common people.