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LA wildfires: Climate change made the disaster worse says WMO

The powerful dry winds and tinderbox conditions that have been fuelling the continuing Los Angeles wildfire tragedy have been made worse by climate change, the UN World Meteorological Organization (WMO) said on Friday.

At least 10 people have been reported killed and more than 10,000 buildings have burned to the ground since the Californian fires broke out and spread, propelled by a well-known weather pattern called the Santa Ana Winds - “high winds from the mountains that cause temperatures to rise and very low humidity, drying out the ground and vegetation,” the WMO said.

Adding to the potential for disaster, the UN weather agency also pointed out that although last year's rainy season for the Los Angeles area was reportedly above normal, “from late 2024 until now, it has been below normal”, which explains why vegetation is so dry.

“It's a terrible tragedy for everybody concerned”, said Clare Nullis, WMO spokesperson, speaking to journalists in Geneva. “It's terrible news for health, for air quality and obviously for people's lives, ecosystems and the local economy”.

Fires still remain uncontrolled in many areas as exhausted firefighters continued to tackle countless blazes, whose original cause has not been confirmed. The National Weather Service in Los Angeles issued a Red Flag warning in effect through Friday morning local time across Southern California, as officials warned that more high winds could fan the flames.

Although wildfires are part of the natural ecosystem in the US west coast as elsewhere, their intensity and frequency have been increasing at an alarming rate in recent decades. WMO said that climate change has exacerbated such disasters, making rainfall heavier in tropical areas and increasing heatwaves.

Destructive wildfires require the alignment of several factors, including temperature, humidity and the lack of moisture in trees, shrubs, grass and forest undergrowth. All these factors have strong direct or indirect ties to climate variability and climate change, explained Ms. Nullis. “Climate change, including increased heat, extended drought and a thirsty atmosphere have been a key driver in increasing the heat and extent of wildfires in the western United States during the last two decades,” she added, citing data from the US National Oceanic and Atmospheric Administration (NOAA).

Evacuation orders and warnings

Hundreds of thousands of people had to leave their homes or have remained under evacuation warnings since the fires broke out last Tuesday. Early warnings are key to avoid dramatic loss of life; WMO said.

“It’s been impossible to save houses,” deplored Ms. Nullis, adding that although the number of victims has been “too high, it has been kept to a relative minimum”.

Early warnings to evacuate are also vital to avoid life-threatening smoke inhalation. Wildfires that burn near populated areas can have a significant impact on human mortality and morbidity depending on the size, speed and proximity to the fire, UN World Health Organization spokesperson, Dr Margaret Harris, explained.

Wildfire smoke is a mixture of air pollutants of which particulate matter (PM) is the principal public health threat, she continued. PM_2.5from wildfire smoke is associated with premature deaths in the general population as it can penetrate deep into the lungs, Dr Harris continued. “It can cause and exacerbate diseases of lung, heart, brain, nervous system, skin, gut, kidney, eyes, nose and liver… And it's also been shown to lead to cognitive impairment, damage your intellectual capacity and cause memory loss.” Firefighters and emergency response workers are at particular risk, she added.

2024 hottest year on record

As wildfires in California continue to rage, the UN weather agency confirmed 2024 was the hottest year on record, ahead of the release of a comprehensive report combining the findings of several regional climate and meteorological monitoring institutes in the UK, China, the EU and the US. “We saw extraordinary land and sea surface temperatures, extraordinary ocean heat, accompanied by, as we all know, very extreme weather affecting many countries around the world, destroying lives, livelihoods, hopes and dreams,” Ms. Nullis said.

The report will be released this Friday, at 17:00 Geneva time (16:00 GMT).

Ends

California destructive wildfires – WMO, WHO 10 January 2025

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