Climate change is making the western United States drier, potentially leading to wildfires like the one affecting Los Angeles.
As temperatures rise, drier landscapes with dense vegetation emerge, which can accelerate and worsen fires.
“Climate change will promote drier landscapes, maintain landscapes that are more susceptible to ignition and burn, and reduce resistance to fire spread,” said John Abatzoglou, a climate scientist at the University of California, Merced. . .
Abatzoglou added that such “spreading” could not only cause large-scale fires, but could also lead to “climbing some of the barriers and entering communities.”
As Southern California burns, global warming is accelerating, both literally and figuratively.
Scientists from the United States and the European Union announced Friday that 2024 was officially the hottest year on record. And, for a change, U.S. carbon emissions that drive climate change There was no significant slowdown last year.a new report discovered last week.
How does warm weather cause fires?
Jatan Buch, a postdoctoral fellow at Columbia University who studies forest fires, said warming makes the air “more capable” of holding moisture.
In fact, the air “actually requires more water” as temperatures warm, said Noah Diffenbaugh, a professor of earth system science at Stanford University.
This “removes water from plants and soil,” he added.
In other words, the air is dry.
Researchers at the University of California, Los Angeles A 2021 study reveals It turns out that the main cause of this thirst, known as lack of vapor pressure in the air, is climate change.
Lack of vapor pressure is a major cause of increased wildfires in the western United States
The study found that 32 per cent of hunger and thirst can be explained by natural climate fluctuations, while the remaining 68 per cent is due to human-induced warming.
In another study, A study from 2020 found that “megadrought” conditions had caused the region's second driest period in 800 years, and were made 46% worse by climate change.
The researchers write that climate change has “put mild droughts on track to rival the worst megadroughts since 800 AD.”
may cause a fire
Dry terrain is just one of the ingredients needed for large fires like California's. First, it needs to be lit, Buch said.
“One is the availability of fuel. Second, the fuel has to be dry enough. And third, these driving factors like wind (in this case the Santa Ana winds) have to make sure that the fires don't start. Make it even more destructive.”
“The climate change component is divided into Part 1 and Part 2,” he says.
Diffenbaugh also noted that the fires are occurring during an unusually dry period, as it is usually the start of the rainy season.
“California is not only warming as the world warms; in fact, California is warming most rapidly in late summer and fall, and there is some evidence that the onset of fall precipitation is slowing. '' he said.
This means that typically during periods of strong winds, there will also be more dry vegetation, he explained.
“There is clear evidence that the climate is changing in a direction that increases the likelihood of severe wildfire weather conditions in the region at this time of year,” he said.
Kevin Speer, a Florida State University professor and director of the Geophysical Fluid Dynamics Institute, said the longer fire season makes it harder to predict extreme fires.
“Climate change means extreme events will become harder to predict,” he said. “Our disaster prediction systems are less reliable than they used to be.”
