Massive fires are raging in several places in the American state of California. On Wednesday evening, a fire broke out in Hollywood Hills in Los Angeles, just over a kilometer from the landmark "Walk of Fame".
It's unusual to have extreme fires in California at this time of year. The main fire season usually lasts into the fall, but rarely into the winter, says Stefan Doerr, professor of natural fires at British Swansea University.
Strong winds
Normally, winter rains would dampen the risk of fires, but California has been dry since last summer.
And when you combine that with very strong Santa Ana winds (dry gusty winds from inland), which are normal for this time of year, you get perfect conditions for extreme fires, says Doerr.
How much impact climate change – mainly caused by human burning of fossil fuels – has on the fires that are raging now is too early to say. So far, no rapid attribution studies – where that type of analysis is done – have been conducted.
So it's hard to say, but what we can say clearly is that the lack of winter rains itself, which has contributed to this fire, is clearly more likely due to climate change.
Longer fire seasons
Since the 1980s, global fire seasons have become 27 percent longer.
In California, the increase has been even greater, so climate change has clearly contributed to an extension of them, says Doerr.
Some parts of Los Angeles, such as fashionable Beverly Hills, are actually bad places to build from a fire safety perspective, with fire-prone vegetation, emphasizes Doerr.
It's a very affluent and pleasant area to live in. So you get a mix of high quality of life with an extreme fire risk.
Igniting spark
Stefan Doerr is a bit surprised by how wild the fires have been, but notes that when risk conditions arise – all it takes is something to ignite. Then it's hard to stop the fires.
They also generate a lot of embers that create new fires when they can fly a bit from the fire source. When buildings burn, they can create embers that can fly long distances. When that happens, it becomes extremely difficult to combat the fires, he says.
