As Los Angeles continues to battle devastating wildfires, attention is turning to why they started, and how much climate change played a role in the outcome.

Los Angeles is not out of the woods yet as a new weather warning for dangerous winds in the northwest of the city could spread blazes even further, although in a different direction.

As residents do their best to pick up the pieces of their ruined lives, questions are being raised about whether authorities did enough to protect the city, and how it all started.

The US National Weather Service (NWS) in Los Angeles doesn’t believe we’ll ever know for sure what started the destructive blazes. It says that 95 per cent of California wildfires are ‘human-caused,’ although that very rarely means arson.

Simple, innocuous actions like a chain dragging behind a truck causing a spark or a discarded cigarette end can be all it takes to start the trail of destruction.

But without climate change and the weather extremes Los Angeles has experienced in the last couple of years, would the fire ever have started at all?

How climate change turned LA into a tinderbox

It’s not the season for wildfires in Los Angeles, but a combination of factors has made this the worst and most expensive fire in the county’s history.

Summer fires tend to be bigger, but burn more slowly. According to US Geological Survey fire scientist Jon Keeley, winter fires “are much more destructive because they happen much more quickly,”

Speaking to Channel 4, Dr Varun Sivaram, a senior fellow for energy and climate at the Council on Foreign Relations claimed that “we could have seen this coming.” 

“We had record rainfall in California for two years and then record dryness or drought that created these bone-dry conditions, where the previous two wet years created a lot of vegetation,” he explained. 

Scientists are calling this flip-flopping between extremes of wet and dry ‘hydroclimate whiplash’. It describes intense periods of extreme but different weather, which lead to more devastating outcomes on both ends of the scale. 

When wet periods follow long spells of dry weather, the ground is less able to absorb the rainfall, leading to flash flooding and landslides. In reverse, drought in an area that was previously wet means there is more vegetation to dry out and more fuel for a fire.

Los Angeles County had been under drought conditions for some time prior to the fire breaking out. The wet season usually begins in October, but there has been a notable absence of rain this season, with very little predicted over the next few days.

This year’s rainy season has brought just 2 per cent of the normal rainfall to the region. Normally, January and February deliver more than 18 cm of the city’s 33 cm of annual rainfall. Weather models suggest no rain at all for the rest of January, and little or none in the first days of February either. 

What are the Santa Ana winds?

While California is no stranger to wildfires, the strength and timing of the winds served to exacerbate the spread of the fire. With dry vegetation on the ground and the winds making things even dryer, only a small spark was needed to launch a devastating firestorm.

“We had these hurricane-speed Santa Ana winds that contributed to these blazes,” said Dr Sivaram. “100-mile-an-hour (160 km/h) plus winds that are blowing embers and spreading the fire faster than anybody could get ready for.”

The fierce Santa Ana winds have been blamed for the rapid spread of the fires, but are they a product of a changing climate too? The winds themselves are a regular feature in the Los Angeles area, blowing strongly from Nevada and Utah into Southern California every year from autumn to early winter.

The winds themselves are incredibly arid, with the lack of humidity adding to the drying of vegetation and making it more combustible. 

The University of Colorado says, “It’s tough to say at this point whether the Santa Ana wind pattern is becoming more or less frequent under climate change,” but states that the frequency and intensity of wildfires are increasing as the climate changes.

Projections for the weather in the days ahead show no rain for Los Angeles County. Thankfully, the winds are not expected to be anywhere near as strong as they have been. 

LA wildfires are a wake-up call for the world

Hydroclimate whiplash is a term we’re all likely to become familiar with over the coming years. According to a research paper published in the journal Nature Reviews Earth & Environment earlier this year, whiplash conditions have increased by up to 31 per cent since the middle of the 20th century.

Should the climate warm to 3C above pre-industrial levels, the paper predicts hydroclimate whiplash to increase by 113 per cent.

“We’re only at about one and a half degrees now, what is it going to be like when it’s 2C or 2.5C above pre-industrial levels?” asked Dr Peter Kalmus, a climate scientist and author. “It’s going to be a nightmare that we can barely imagine right now.”

While LA burns, political disputes and criticism have distracted from practical actions.  Even when the dust settles, the best we can hope for is more stringent controls of firebreaks and better water management. But Dr Kalmus says that’s not enough.

“These kinds of little adaptations, we need to do them, but it’s going to be a little bit like trying to stop a huge wildfire like this with a garden hose,” he said. “We have to address the root cause, which is fossil fuels, as quickly as we can for our survival.”

Dr Kalmus believes that, in the future, humans will be dealing with multiple impacts at the same time, which will be devastating if we are not prepared. Specifically, he cites major food shortages, heat waves, and drought, adding that a major intervention is needed to avert the worst of the consequences.

“The fossil fuel industry in the 70s saw this coming with uncanny accuracy,” said Peter Kalmus. “They chose to spread disinformation and block action when they could have chosen to alert world leaders and work with us to transition. That’s the choice I would have made. It’s just the biggest moral failure, I think, in human history.”

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