by Circumstantial evidence points to climate change and the deadly deluge that just inundated Dubai and other parts of the Persian Gulf is getting worse, but scientists haven’t found the definitive fingerprints of greenhouse gas warming they’ve seen in other extreme weather events, found out in a new report.
Between 10% and 40% more rain fell in one day last week – killing at least two dozen people in the United Arab Emirates, Oman and parts of Saudi Arabia – than would have happened in a world without the 1.2 degrees Celsius (2.2 degrees). Fahrenheit) of warming that has come from burning coal, oil and natural gas since the mid-19th century, scientists at the World Weather Attribution said Thursday in a flash study that is too new to be peer-reviewed.
In at least one location, a record number of 11 inches (28.6 centimeters) of rain fell in just 24 hours, more than twice the annual average, paralyzing the city usually bustling with skyscrapers in the desert.
One of the key tools in more than 60 previous WWA reports is to create computer simulations that compare an actual weather event to a fictional world without climate change, but in the case of Dubai there was not enough data to run those simulations. . But analysis over the years, the other main tool they use, has shown a 10% to 40% bump in rainfall amounts.
Even without computer simulations, the clues still pointed to climate change, scientists said.
“It’s not such a clear fingerprint, but we have a lot of other circumstantial evidence, other lines of evidence that tell us we’re seeing this increase,” said the Imperial College of London climate scientist. Friederike Otto, which is coordinated by the allocation study team. “It’s what we expect from physics. That is what we expect from other studies that have been done in the field, from other studies around the world, and there is nothing else going on that could explain this increase.”
There is a long known effect in physics that finds that there is 7% more moisture in the air for every degree Celsius (4% for every degree Fahrenheit).
Otto said she is confident in the conclusion, but said this was one of the more difficult allocation studies the team has done.
El Nino, which is a natural periodic warming of the central Pacific Ocean that alters weather systems around the world, was a major factor, the report said. Heavy Gulf spills have only occurred during El Nino in the past. And the researchers said those past floods appear to be getting heavier — something scientists have long said would happen in many parts of the world as the world warms.
This flooding, which came from two separate and adjacent storm systems, would not have happened without El Nino, said study co-author Mansour Almazroui of the Center of Excellence for Climate Change Research (CECCR) , King Abdulaziz University in Saudi Arabia. It wouldn’t be like this either without human-caused climate change, Otto said.
Because rainfall amounts varied across the region and the lack of data, the report was unable to put a figure on whether climate change has increased the likelihood of such a downpour in Dubai, but Otto reckoned it was likely three times more likely now. than in pre-industrial times.
The report and its authors threw cold water on speculation that UAE cloud seeding was related to the amount or likelihood of rainfall. Many scientists dispute the effectiveness of cloud seeding in general. However, the clouds were not seeded in the storm system, the report said. And the results of cloud seeding, if any, are generally more immediate, Otto said. And this storm was predicted days in advance.
“This type of rain does not come from cloud seeding,” Almazroui said at a news conference on Thursday.
Although the authors use established techniques and this is what scientists expect when it comes to climate change, when there is a disagreement between computer simulations and observations, conclusions should not be drawn, said climate scientist Andrew Weaver , University of Victoria, Canada, did not. t part of the research.
It’s a pretty strong case that greenhouse gas emissions are a factor, several other outside scientists said.
Climate scientist Malte Meinshausen, University of Melbourne, Australia, called Thursday’s study “a well-balanced, impressively detailed and quite cautious assessment.”
“When this work is combined with theory and attribution studies of other increasingly frequent extreme rainfall and flood events around the world, it makes a convincing case that climate warming has outpaced the rainfall and flood event recently UAE and Oman,” said climate scientist Jonathan. Overpeck, Dean of the University of Michigan’s School of the Environment. “This is what more global warming looks like – more severe climate extremes and human suffering.”
__
Read more about AP’s climate coverage at http://www.apnews.com/climate-and-environment
___
Follow Seth Borenstein on X at @borenbears
______
The Associated Press’ climate and environmental coverage is financially supported by multiple private foundations. AP is responsible for each and every subject. Find AP standards for working with philanthropies, a list of supporters and covered areas of funding at AP.org.
