Deadly wildfires are spreading in northern and southern California

The Camp Fire is now the most destructive fire in state history, and has claimed at least 23 lives.

The Camp Fire burning near Chico, California is now the single most destructive and third-deadliest fire in state history. And it’s just one of two major infernos raging in the Golden State this weekend as late-season winds pick up and spread walls of flames.

The Woolsey Fire in southern California is threatening lives and property too, and is poised to spread further. Already more than 300,000 people have been forced to evacuate statewide.

The Camp Fire has so far torched more than 109,000 acres since igniting Thursday morning. At one point, it was growing at a rate of one football field per second. The fire has killed at least 23 people and incinerated more than 6,400 structures. Paradise, home to 26,000, was almost entirely laid to waste by the fire.

“The town is devastated, everything is destroyed,” California Department of Forestry and Fire Protection (Cal Fire) spokesperson Scott Maclean told Reuters. “There’s nothing much left standing.”

You can see the massive smoke clouds in this satellite photo (the red is infrared heat, not actual flames):

The fire has forced more than 50,000 people to evacuate, some on foot. Towering plumes of smoke, soot, and ash filled the skies and spread to communities hundreds of miles away like Santa Rosa, the site of last year’s Tubbs Fire, then the most destructive blaze in state history. As of Sunday morning, the blaze is 25 percent contained.

The governor’s office declared a state of emergency for the region and requested federal aid.

Farther south, two other blazes ignited Thursday near Los Angeles and turned the sky orange. The Woolsey Fire has burned 83,200 acres so far with 10 percent contained. Two bodies were found in the path of that fire, though the cause of death is not yet official, the Washington Post reports. Firefighters are gaining ground against the Hill Fire, which has ignited 4,500 acres. The blaze is 65 percent contained.

Seasonal Santa Ana winds with gusts up to 60 miles per hour have rapidly spread the flames. Both of these fires are in Ventura County, where the 282,000-acre Thomas Fire burned late last year.

This is actually the second round of big, dangerous fires in California this year. The Thomas Fire was only extinguished in January. Then the gargantuan Mendocino Complex Fire sparked and burned more than 459,000 acres in July. And in August, the deadly Carr Fire started in Shasta County.

You can see the current rash of fires in this map from Cal Fire:

If this seems like a pattern, it is. And it is poised to get worse in many parts of the state as average temperatures rise with climate change.

But remember that wildfires are a natural part of the ecosystem. They provide a vital service to forests and grasslands, clearing out decaying brush and helping plants germinate. However, the massive wildfires we’ve seen in recent years are hardly natural; humans have made them worse at every step.

For one thing, people are building increasingly closer to grasslands and forests that regularly burn. This increases the likelihood of people igniting fires and the damage from the fires that do occur. Humans already ignite the vast majority of wildfires. Active fire suppression tactics have also prevented smaller fires from burning, allowing fuel to accumulate and drive surging conflagrations.

Human activity is also changing the climate. Warmer temperatures have caused forests in the western United States to dry out, killing off 129 million trees in California alone, leaving many regions littered in dry fuel.

As such, fire officials no longer talk about fire seasons but fire years. According to Cal Fire, California has seen almost double the area burned across its service territory than at the same time last year. More than 1.3 million acres have burned throughout the state this year and more than 8.3 million acres across the United States as a whole.

On Saturday morning, President Trump blamed “gross mismanagement of the forests” for the fires and threatened to withhold federal funding from California.

The National Weather Service reported that winds have slowed down in Northern California, which should give firefighters some relief and slow the spread of the Camp Fire. And in Southern California, winds are likely to continue blowing, so the fires could grow.