The recent downpour in Dubai that left 18 people dead and caused devastating infrastructure damage has raised the question of whether cloud seeding was to blame.
Schools across the United Arab Emirates (UAE) were shut and remained closed for the remainder of the week while Dubai Mall and Mall of the Emirates was filled with ankle-deep water.
Viral videos of cars floating through traffic have emerged.
But the question on everyone’s lips: Did cloud seeding cause the floods?
IOL spoke to two South African experts — Lehlohonolo Thobela Meteorologist weather forecaster at the South African Weather Service (Saws) alongside Professor Tafadzwa Mabhaudhi, a Professor of Climate Change, Food Systems and Health London School of Hygiene and Tropical Medicine — to explain cloud seeding, its impact, cost and effects.
What is cloud seeding?
Thobela: Cloud seeding is an artificial weather modification technique that aims to improve a cloud’s ability to produce rain or snow by introducing tiny ice nuclei (silver iodide) into certain types of cold clouds.
Potassium chloride is used for warm clouds. Maritime type clouds have a low drop concentration with a broad drop size, whereas continental origin clouds have a high drop concentration with a narrow drop size.
What is the purpose of cloud seeding?
Thobela: The purpose of cloud seeding was so that areas that were struggling to produce rain get to have the potential for rainfall stimulation.
It was also used to create now flakes for regions that never experience snow as well as be able to suppress the formation of hail in a storm by over seeding a cloud.
What are the pro’s and cons of cloud seeding? Thobela answers:
Pro’s:
– Rainfall in an area that struggles to produce it.
– The ability to enhance the ability of snowflakes.
– Good for agriculture in areas that under go water insecurities.
Cons:
– It may result in harmful rain “Acid rain” that may be of a hazard for growing vegetation as well as cause an irritation for human behaviour.
– It may result in health issues, such as respiratory diseases.
– Contamination of air.
– Decrease the air quality.
Which countries endorse or allow cloud seeding?
Thobela: South Africa was one of the countries that practised cloud seeding over last five to 10 decades for a couple of years, where it was done in Bethlehem as well as in the Nelspruit to asses the potential for the stimulation of rainfall.
Mabhaudhi: Many countries do cloud seeding, for various reasons, usually to encourage cloud formation and precipitation. Countries like the UAE, Saudi Arabia, and even here in Africa use cloud seeding - South Africa, Zimbabwe, etc. nowadays less so because of the expenses involved.
Does cloud seeding impact the environment?
Mabhaudhi: There is no established evidence showing any negative impacts of cloud seeding. It’s a practice that has been around for decades. It’s not commonly used because it’s expensive.
What does cloud seeding cost?
Mabhaudhi: Cloud seeding is very expensive and the costs will vary per country depending on various other factors. Available information shows it can cost about $5000 for a four-hour operation that seeds about 24 clouds. So, it’s an expensive operation.
Did cloud seeding cause the recent floods in Dubai?
Mabhaudhi: No. This has been a misconception. The heavy rains in Dubai were caused by a cut off low system which developed in the region. This was a regional weather system which forecasters had predicted prior to the event.
Also, no, we cannot directly attribute it to climate change without any proper attribution studies, which will take time to be done.
However, we can generalise that the flash floods are consistent with known climate change impacts which are also being observed elsewhere - increasing intensity of extreme weather events. The fact that we are coming off several record breaking months in terms of global temperatures, means that we have a more atmosphere, which therefore makes it possible to fuel and intensify storms.
Thobela: I am by no means saying cloud seeding was the cause of the Dubai floods or anything that side. My opinion is based on meteorological influence and all-weather systems. I am not familiar with the operations of the weather office in Dubai.
For a severe weather event to happen, there must be a weather system that drives the impacts and the development. For example, an upper air weather system like a cut-off-low, that results in an unstable atmosphere and eventually influencing a development of a convective cloud that will bring about heavy downpours which eventually lead to localised floods.
The UAE’s take on cloud seeding?
According to the National Centre of Meteorology in the United Arab Emirates (UAE) is considered one of the first countries in the Arabian Gulf region to use cloud seeding technology. They say they have adopted the latest technologies available at the global level.
The NCM said it uses advanced air radar that monitors the country’s atmosphere around the clock.
In addition to using a private plane equipped with special salt burners.
These were manufactured to suit the physical and chemical nature of the clouds that form within the United Arab Emirates.
These clouds are studied for years before starting to implement rain seeding operations in the country.
“We classified these clouds and identified the appropriate clouds.”
Through this study, it was found that the best clouds for rain seeding are those that form in the summer in the eastern and south western regions.
Cloud seeding operations are considered one of the operations that require precision in the method of seeding, as the aircraft is directed to the appropriate place and at the appropriate time, in order to ensure the desired goal of these operations.
According to the website they own six rain seeding planes.
Cloud seeding to combat pollution?
In November last year, India apparently wanted to use cloud seeding technology to clean poisonous smog in the capital with rain, AFP reported.
However it was met with critic from environmentalists fearing that it was an expensive distraction from tackling root causes.
The country is apparently known as the world's worst capital for air quality, AFP reported.
Sachchida Nand Tripathi, a professor of sustainable energy engineering at the Indian Institute of Technology (IIT) at Kanpur, said aeroplanes equipped with seeding equipment or ground-mounted guns would be used to induce rainfall.
She said cloud seeding has produced positive results, and "has not shown any adverse effect wherever it has been tried".
AFP reported that the cost involved could be as high as 10 million rupees ($120,000) to seed 100 square kilometres.
It reported that other countries like China, Malaysia and Indonesia have extensively used cloud seeding technology to improve air quality.
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