Press
Dubai is experiencing unusually heavy rainfall. While some point to cloud seeding as the cause, experts see another culprit.
Dubai – The heavy rainfall that fell on Dubai on April 16 has sparked speculation: Could it be the result of “cloud seeding”? Experts disagree with this theory for various reasons. Edward Gryspeerdt from Imperial College London explains: “Cloud seeding is about increasing precipitation from vulnerable clouds.” Not every cloud is suitable for this. “You cannot create a cloud or rain out of nothing,” emphasizes the expert. “You need a cloud that is already on the verge of forming rain and that you can then ‘flip’ into rain.”
The effectiveness of cloud seeding, i.e. seeding a cloud that then rains down, is difficult to determine, as Gryspeerdt further emphasizes: “Once you seed a cloud, you don’t know whether it wouldn’t have rained anyway. Because the inoculated clouds were already close to rain, it is difficult to determine what effect the inoculation has had.” Giles Harrison from the University of Reading shares this view. He points out that although the United Arab Emirates does cloud seeding, there is a significant difference between what this method can achieve and the heavy rain in Dubai.
Dubai rains: Experts see climate change as the culprit
Harrison points out: “The processes involved are so disparate in scale that I can’t see how the rain and cloud seeding could be related. Furthermore, given the forecast of heavy rain, there would be no reason to carry out cloud seeding under these circumstances.” The scientist looks in a different direction: “It has long been expected that an increase in atmospheric moisture with a warmer climate will lead to more extreme precipitation events .”
Other experts also see climate change as the real culprit. John Marsham of the University of Leeds calls the suggestion that Dubai’s rains could be linked to cloud seeding “a distraction from the real story.” He explains: “We know that man-made climate change is increasing extreme rainfall. This is a well-understood physical fact, as warm air contains more water.” Marsham is convinced: “Any possible effect of cloud seeding would be tiny under the circumstances of Dubai.” In addition, weather models had already indicated the risk of heavy rain days before.
“Focusing on cloud seeding is misleading”
Friederike Otto from Imperial College London agrees: “If we talk about heavy rainfall, we have to talk about climate change. Focusing on cloud seeding is misleading.” She emphasizes that cloud seeding, a geoengineering method, cannot create clouds out of nothing. “Even if cloud seeding had caused the clouds around Dubai to shed water, the atmosphere would likely have allowed more water to form clouds beforehand due to climate change,” Otto adds.
The scientist warns: “If people continue to burn oil, gas and coal, the climate will continue to warm, rainfall will continue to increase and people will continue to lose their lives in floods.” However, other experts also warn of “weather wars”. Related to cloud seeding.
Heavy rains over Dubai: triggered by a “mesoscale convective system”
Suzanne Gray, a meteorologist from the University of Reading, explains the rain phenomenon in Dubai as a “mesoscale convective system.” This occurs when many individual thunderstorms combine to form a large cloud shield and cover a large area with heavy rainfall. “They are not rare events for the Middle East,” she emphasizes. A recently published study shows that such weather events occur most often in March and April. A similar event in March 2016 dropped more than 240 millimeters of rain over Dubai in just a few hours – comparable to current rainfall.
Maarten Ambaum from the University of Reading confirms: “These intense rainfall events may become more extreme due to climate change.” “Climate scientists have been warning for many years that such extreme events will become more likely in a warmer climate, and indeed we are now seeing this around us.” (tab)