After nearly two years’ worth of rain flooded the Dubai region Tuesday, attention quickly shifted to cloud seeding and whether it could have been a factor in the deluge. The geoengineering technology has successfully produced rainfall over the arid United Arab Emirates in the past.
The UAE National Center of Meteorology told CNBC it did not conduct any cloud-seeding operations during the storm, countering a Bloomberg News report that said geoengineering intensified the rainfall. Efforts by The Washington Post on Wednesday to reach the center were not successful.
Even if cloud seeding did occur, it would take sophisticated research to determine whether it increased the rainfall — something that has proved difficult in past scientific inquiry. Without that, one has to assume geoengineering was not a factor, said Andrew Dessler, a climate scientist at Texas A&M University.
“Show me the analysis that shows it was cloud seeding,” Dessler said. “Without seeing some analysis, your null hypothesis has to be that it did not contribute.”
What is cloud seeding?
The practice involves injecting a chemical known as silver iodide into clouds that contain large amounts of water vapor. The substance can encourage the formation of ice crystals, which promote precipitation in the form of rain or snow.
The practice is decades old and has been used around the world and across the United States, including in California, Nevada, Colorado, New Mexico, Wyoming, Kansas, Oklahoma, Texas, North Dakota, Utah and Idaho, according to the Desert Research Institute.
Research has shown signs the technology can increase snowpack in the American West, for example, though not at a level of statistical significance that has thus far convinced many meteorologists that it actually works.
Other research has been more definitive about cloud seeding’s effectiveness, though with results not easily reproduced. A research effort known as the SNOWIE project found the practice produced enough snow to fill 282 Olympic-size swimming pools in about two hours.
Still, it is known to work only under certain circumstances, when clouds are rich with moisture, Dessler said.
What happened in Dubai?
The floods that hit the UAE were significantly more extreme than what is considered a 1-in-100-year flood there — an event that carries a 1 percent chance of occurring in any given year.
In Al Ain, about 75 miles southeast of Dubai, the National Center of Meteorology reported 254.8 millimeters of rainfall — more than 10 inches — in less than 24 hours. The center called it “an exceptional event … in its climatic history” and the country’s heaviest rainfall in 75 years.
Close to 5 inches of rain fell at Dubai International Airport, where about 3 inches of rain is normal in an entire year.
Today’s extreme rain event in Dubai was clearly associated with a synoptic configuration that increased the odds of excessive rainfall.
— Tomer Burg (@burgwx) April 17, 2024
A slow-moving, positively tilted trough with a strong plume of moisture transport led to record high PWAT for April: https://t.co/vL3ZAbqkIH pic.twitter.com/Opoc8B8mRP
Meteorologists said significant amounts of rain would have fallen with or without cloud seeding. It was the product of a slow-moving area of relatively low atmospheric pressure and abundant moisture in the air.
The scale of rainfall was also much larger than what cloud seeding could have produced, according to Giles Harrison, a professor of atmospheric physics at the University of Reading in Britain. Given that heavy rain was in the forecast, there would have been no obvious reason to attempt cloud seeding, he added.
What role does climate change play?
Friederike Otto, a climate scientist at Imperial College London who leads a research effort to explore the role of climate change in extreme weather events, called any focus on cloud seeding in the floods “misleading.”
Instead, she and other scientists pointed to the fact that warming global temperatures are producing heavier rainfall around the world because warmer air can hold more moisture.
“Even if cloud seeding did encourage clouds around Dubai to drop water, the atmosphere would have likely been carrying more water to form clouds in the first place, because of climate change,” she said in a statement.
Otto said in an email that she is not certain whether her group, World Weather Attribution, will explore the role that climate change may have played in the latest floods.
“It’s definitely an interesting event in a region we haven’t studied much,” Otto told The Post.
