Dubai deluge likely made worse by warming world, scientists find

A powerful rainstorm that wreaked havoc on the desert nation of the United Arab Emirates last week was likely made more in‐ tense because of climate change, a team of interna‐ tional scientists has found.

The World Weather Attri‐ bution (WWA) group, com‐ posed of researchers from around the globe, said rain storms like the one that struck last Monday have be‐ come 10 to 40 per cent more intense because of humaninduced climate change.

The storm was also a product of El Niño, a natural, cyclical warming in the Pacific Ocean that leads to more rain in the region, the re‐ searchers said.

"Both El Niño and humancaused climate change ap‐ pear to be influencing heavy rainfall in the UAE and Oman," said Friederike Otto, a climate scientist at Imperial College London, and one of the authors of the study.

"While we can't stop El Niño, we can stop climate change."

The WWA, founded in 2015, studies extreme weath‐ er events, such as droughts, floods and heat waves in an attempt to determine the role played by climate change. The study was not published in an academic journal, but relies on peer-re‐ viewed techniques, the re‐ searchers said.

Across the UAE and Oman, flooding damaged buildings and cars, and resul‐ ted in power outages and school closures, the study said.

WATCH | Dubai residen‐ ts wade through aftermath of flash floods:

Flash flooding caused 19 deaths in Oman, including 10 children who died when a school bus was swept away.

In the UAE, four people died in cars in floodwaters.

More than 1,000 flights were cancelled with several days of delays after a runway was flooded at Dubai Inter‐ national Airport, one of the world's busiest. The rain also affected Bahrain, Qatar and Saudi Arabia.

Unprecedented rainfall

In Dubai, more than 14 cen‐ timeters of rain fell over 24 hours between April 14 and 15, which is equivalent to a year and a half of rainfall in the desert city, and the heav‐ iest to fall in the UAE since records began in 1949.

In this case, the re‐ searchers were not able to draw as direct a connection to climate change as they have in previous studies.

As part of its calculations, the WWA usually uses com‐ puter modelling to compare a weather event to one in a simulated world without cli‐ mate change.

In this case, there weren't enough publicly available da‐ ta points to make such a comparison.

But the researchers were able to study past observa‐ tions, the other main tool they use, to determine the 10 to 40 per cent increase in rainfall amounts.

Despite the limitations of the analysis, Otto said at a Thursday news conference it's clear that in future, during

El Niño years, "it will rain more than it would have if we were not continuing to burn fossil fuels and warm the climate."

The report ruled out spec‐ ulation that cloud seeding had played a role in the heavy rainfall.

The researchers said that given the size of the storm system, the rainfall would have fallen regardless of whether operations had been carried out - and that a storm had been expected for days.

"This type of rainfall never comes from cloud seeding," said Mansour Almazroui of the Center of Excellence for Climate Change Research at King Abdulaziz University in Saudi Arabia, one of the study's co-authors.

Adaptation in the desert

Nathan Gillett, an expert in attribution science and re‐ search scientist with Environ‐ ment and Climate Change Canada, who was not in‐ volved in the WWA study, said the link between climate change and the event is not as well defined as it has been in other attribution studies, given the data limitations.

"The direct modelling of this event is less conclusive," he said. More broadly, though, Gillett said research suggests climate change is

leading to increasingly ex‐ treme rainfall events in the region.

WATCH | Breaking down

Dubai's historic rainfall:

Almazroui said the find‐ ings underscore the need for improved adaptation to heavy rainfall in the region, and for an effective alert sys‐ tem.

Roop Singh, a specialist at the Red Cross Red Crescent Climate Centre, said in this case the rainfall was well forecast and dangerous flooding was expected; the majority of fatalities occurred inside vehicles.

"It is critical that future flooding preparations focus on early warning to ensure people aren't in harm's way when extreme rainfall hits the Arabian Peninsula," Singh said.