Storm surge: How extreme weather events have ravaged ecosystems in the past 20 years

This year's flooding in the UAE came amid a string of severe weather events

Dubai's roads were badly affected by flooding in April. Chris Whiteoak / The National

Record storms caused severe floods in the UAE and Oman in April and, with climate change expected to increase rainfall by 20 to 30 per cent in future, these events could become more common.

With similar events reported around the world, The National has examined some of the worst storms globally over the last 20 years and how they have affected ecosystems.

Climate scientists forecast greater variation in precipitation patterns, with more extreme rainfall, droughts and forest fires expected. Severe rain becomes more common as the atmosphere can hold about seven per cent more moisture for every 1°C rise in temperature.

Prof Georg Winkel, a forester and ecologist at Wageningen University and Research in the Netherlands, observed floods that struck Central Europe in July 2021. One of the affected areas was the Ahr Valley in Germany, which he said tended to be hit by extreme floods about once a century. Higher population densities and even more extreme precipitation patterns mean the effects now are greater.

“Even if you have a history of extreme flooding, you can see the impacts of climate change because they’re getting more likely,” he said. "[There are] even higher impacts due to warmer air and more moisture.”

Climate change is blamed for causing an increase in the intensity of severe tropical storms – hurricanes, cyclones and typhoons. “The warmer air is able to hold more moisture. That’s favourable conditions for tropical cyclones to grow,” said Dr Xiangbo Feng, a senior research scientist in tropical cyclones at the UK's National Centre for Atmospheric Science.

“And the warmer sea-surface temperatures means the ocean is holding more heat. The more ocean heat, the more can be converted into the energy of tropical cyclones, so the energy the tropical cyclones absorb from the ocean is going up.”

Due to the factors related to the differences in warming, and its effects on wind patterns, certain areas, such as the North Atlantic, are more heavily affected by storms, compared to the north-west Pacific.

As well as death and destruction, extreme storms also cause environmental issues, leaving coastal areas inundated, river valleys flooded and sparking landslides. Here we consider the human and ecological impacts of storms from the past two decades.

Hurricane Katrina, August 2005

The storm killed about 1,400 people when it caused widespread flooding in and around New Orleans. The hurricane is remembered due to the response, or lack of it, by authorities after the storm. It also badly affected the environment.

“Katrina left an environmental toll of oil spills, storm debris, damaged sewage and water treatment systems, abandoned housing, and widespread mould,” researchers from the Louisiana State University Health Sciences Centre wrote in the American Journal of Public Health in 2020.

LSU Libraries said that the hurricane caused the United States’ worst oil spill since 1989, with between 7 million and 8 million gallons released. “Another major concern following the 2005 hurricane season was the condition of the Gulf Coast and the destruction of ecological habitats,” LSU Libraries stated.

“The damage wrought upon Louisiana’s vulnerable wetlands by Katrina was exacerbated by subsequent storms throughout the following months.”

Storm surges and extreme winds caused coastal erosion, including to the barrier islands off Louisiana, which are remains of the Mississippi Delta. Floodwaters, polluted with heavy metals and pathogens, ended up in the Lake Pontchartrain estuary.

Cyclone Nargis, May 2008

Thanks to storm surges in the Irrawaddy Delta in Myanmar, this tropical cyclone – which took its energy from warm waters in the Bay of Bengal – killed more than 138,000 people. Causing winds of up to 215kph, the storm has been described as the worst natural disaster in the history of the South-East Asian nation.

The effects of Cyclone Nargis extended to the natural environment, with 38,000 hectares of mangroves and other tree areas widely reported to have been destroyed.

In a 2017 study in Comptes Rendus Geoscience, a team of French-based researchers reported that the cyclone flooded 14,400km of inland areas of the delta. “The shores and multiple mouths in the protruding western half of the delta … took the brunt of the cyclone,” the researchers wrote.

Three months after the cyclone, the shoreline in the delta had retreated by an average of 47 metres, the researchers found, with some areas experiencing a retreat of more than 200 metres. They compared some shoreline retreat to that caused by Hurricane Katrina and said there was “marked and persistent erosion” 20 months later.

Central Europe floods, July 2021

A string of Central European nations were badly affected by flooding in July 2021, when as much as 271.5 millimetres of rain fell in two days. About 250 people died, the majority in Germany and Belgium, with the Belgian Interior Minister, Annelies Verlinden, describing it as, “one of the greatest natural disasters our country has ever known”.

Prof Winkel said that while the effects on people were “disastrous”, especially because population densities were higher than during previous flooding events, in some locations, such as the Ahr Valley in Germany, areas were “rewilded” because the river ecosystem spread out into areas from which it had been excluded.

“[Areas] were taken over by the river … The river came back into areas where it’s been cut away through dykes and other technical measures,” he said. “ … More extreme events are a likelihood when the air is warmer and can carry more water. It changes river systems beyond what they were in the past. The effects are more harmful to people than to the ecosystem.”

Typhoon Yagi, September 2024

This extreme weather event caused heavy flooding and landslides and left a trail of destruction when it hit North Vietnam in early September. It was the most severe typhoon to hit the region in decades and also affected the Philippines and parts of China.

Tens of thousands of people had to flee their homes and more than 300 were left dead or missing after the super typhoon caused downpours and winds that exceeded 200kph. There was heavy damage to infrastructure, with buildings, roads and bridges all suffering damage due to the extreme conditions.

Power cuts were widespread, affecting about 200,000 homes, according to the International Federation of Red Cross and Red Crescent Societies (IFRC). Nature was also badly affected, with more than 300,000 trees uprooted. Hundreds of thousands of hectares of farmland were flooded and about three million farm animals died.