Even though it has existed for several decades, cloud seeding technology is still controversial in the weather community, especially after the catastrophic flood that flooded the United Arab Emirates (UAE).
There have been no reports of the type of flooding that raged in the UAE on April 16. Many media outlets blame the cause of the floods on cloud seeding operations that Dubai regularly conducts to address its need for clean water. According to Ahmed Habib, an expert at the National Center of Meteorology (NCM), the UAE conducted cloud seeding operations a few days before the rain. The aircraft was deployed from Al Ain airport to influence convective clouds forming in the region, according to Interesting Engineering.
Dubai city was completely paralyzed after heavy rain caused the area to record a year’s worth of rain in just 24 hours. Schools closed and staff were asked to work remotely after underground car parks were flooded. Metro services were also disrupted due to the two-day rain. Dubai International Airport, one of the busiest in the world, faced severe operational impacts with flights having to be diverted or delayed by several hours. The damage is not limited to Dubai. Streets in the capital Abu Dhabi were also flooded, while a 70-year-old man was killed when his car encountered flash floods in Ras Al Khaimah.
Meteorologists and climate scientists said the heaviest rain in 75 years was likely the result of human-caused climate change. One way to know for sure that an event is not related to cloud seeding is to have a prediction several days in advance. Atmospheric science researcher Tomer Burg said computer models predicted several tens of centimeters of rain six days in advance, equal to the amount of rain in the entire year in the UAE.
Many of the people who blame cloud seeding technology are also those who deny climate change is happening. “When we talk about heavy rain, we need to talk about climate change. Focusing on cloud seeding technology is confusing,” said climate scientist Friederike Otto at Imperial College London. “Rain is becoming much more intense around the world as the climate warms because the warm atmosphere can hold more moisture.”
Cloud seeding technology
Clouds need tiny drops of water or ice called nuclei to create rain. Weather modification uses aircraft and guns on the ground to spray particles into clouds to create more cores, thereby increasing humidity and promoting water to fall as snow and rain. Typically, authorities use silver iodide, dry ice or a variety of other materials. Cloud seeding technology was first used in the 1940s, becoming popular in the United States in the 1960s, mainly for snowmaking. This method cannot create rain when the sky is clear, the particles must be shot into storm clouds that already have moisture for water to fall.
However, the scientific community does not know exactly how effective cloud seeding technology is. The method seems sound in theory, but the results are so small that researchers can’t agree on whether it’s true to say cloud seeding technology actually works. Atmospheric forces are so large and chaotic that cloud seeding is “too small in scale to create change,” Maue said.
Theo Bloomberg, UAE has been using cloud seeding technology since 2002 and has never encountered a flood disaster in the past two decades. Experts are certain that the cloud seeding technology was not faulty this time because Dubai conducts about 300 such operations each year. NCM also confirmed that they did not conduct cloud seeding on the day the storm hit. Although cloud seeding may seem like a victory for humans over nature, this technology can only increase rainfall by 25%. In other words, human intervention cannot create rain when rain clouds do not appear in the sky. Even as rainfall increases in Dubai, the role of cloud seeding technology is relatively small.
According to Wired, cloud seeding has a very local effect. Most of the cloud seeding in the UAE was carried out in the eastern regions, away from Dubai, where the heavy rain occurred. Oman also experienced heavy rain, although no cloud seeding operations were carried out.
Cause of heavy rain
Three low-pressure systems formed a series of storms that moved slowly along the jet stream, a stream of fast-moving air at high altitudes, toward the Persian Gulf, according to climate scientist Michael Mann of the University of Pennsylvania.
The UAE is located in a region of the Middle East that doesn’t have many storms, but when storms do appear, they are major storms that far exceed those in the United States, according to Maue. Huge tropical storms like this “are not rare events in the Middle East”, said meteorology professor Suzanne Gray at the University of Reading. A recent study analyzed nearly 100 similar events in the southern Arabian Peninsula from 2000 to 2020, most of which fell in March and April, including a storm in March 2016 that dumped nearly 24 centimeters of rain. down to Dubai within a few hours.
According to Reuters, the storm initially swept through Oman on April 14 before reaching the UAE on April 16, causing power outages, disrupting flights and turning highways into rivers. In the UAE, a record rainfall of 254 mm was recorded in Al Ain, a city bordering Oman. This is the heaviest rainfall in a 24-hour period since records began in 1949.
Research in 2021 shows a significant increase in the duration of strong storms in the southeastern Arabian Peninsula. Such extreme events could have a greater impact as the world warms. Although cloud seeding technology is effective, scientists say it does not have a big impact.
Dubai flooded because it was not built to handle excessive rainfall. The desert city is looking to increase its fresh water supply without building sewers to carry water during heavy rains. The city is built of concrete and glass, with no infrastructure to absorb excess water. In the context of climate change, the situation of large cities being flooded during continuous heavy rains is very common, including Dubai. This is a wake-up event proving that urban infrastructure needs to be redesigned to adapt to climate change.
“Certainly the cause is not cloud seeding technology,” said meteorologist Ryan Maue, former chief science officer at the US National Oceanic and Atmospheric Administration. “If that happens with cloud seeding technology, the whole UAE will be flooded all the time.”