California megafires and the future

Record heat is fueling an accelerating megafire crisis in California. The ongoing massive Park fire is the latest monster to burn off the old-climate charts. 

Before 2018, the state's largest wildfire on record was the Thomas fire, which burned 280,000 acres. At the time, the Thomas fire felt apocalyptic. The current Park fire burned more in just its first three days. It's currently the state's fourth-largest on record, at 430,000 acres -- joining the rapidly swelling ranks of unprecedented megafires.

Beyond California, forests all over the world are also getting baked by record-breaking heat. As everyone knows by now, the primary driver of this global heating is pollution from burning fossil fuels -- oil, gas and coal. Extreme heat events are turning forests into kindling. Californians, like people in many other parts of the world, are at the sharp end of this stick. 

Hottest July on record

This year California suffered through its hottest July on record. That's according to NOAA data stretching back 130 years.

By the end of that record-hot month, the forests were baked and ready to burn. 

The Park fire started on Wednesday, July 24. Less than two hours after it sparked, it was listed at 40 acres in the state's first incident report. An hour after that, the first evacuation orders went out. Less than 24 hours later, it had exploded to over 70,000 acres. The next day, it hit 165,000 acres. And on Saturday, just 72 hours after it started, the Park fire had burned 350,000 acres.  

As noted above, that already exceeded any California wildfire on the books before 2018. 

At the peak of the Park fire, more than 6,500 firefighters were fighting it -- using 525 fire engines, 190 bulldozers, 180 water tenders, 45 helicopters, and a fleet of airplanes dropping water and fire retardant. 

The cost and effort needed to attack these hotter-climate monster fires is daunting. California boasts the world's fifth-largest economy and will be able to pay for such Herculean efforts longer than most other parts of the world. 

But, as the next chart shows, even California, with all its resources, is already losing the battle. 

California's exploding megafire crisis

To illustrate the stunning acceleration of the state's wildfire crisis, I created the chart below. It shows California's 40 largest wildfires, arranged by the year they burned. The height of each bar shows how many acres each fire burned. 

Chart: California's 40 largest wildfires since accurate, modern records started being kept around 1930. The height of each bar shows acres burned. The horizontal axis is the year the fire occurred. Data from archived versions of CalFire's top 20 wildfire tables. Chart by Barry Saxifrage, NationalObserver.com. August 2024

As you can see on the left side of the chart, when we all lived under the blessings of a stable, lower-energy climate, Californians rarely had to deal with megafires. And when they did, the biggest fires topped out at around 200,000 acres.  

Now, billions of tonnes of fossil fuel pollution later, we live under the shadow of an increasingly destabilized and higher-energy climate. And California megafires have responded with rising frequency and fury. 

First came a dramatic surge in the frequency of big fires. You can see this on the chart with the pile up of orange bars starting in the new millennium. Gone are the peaceful decades, like the ones I grew up in, with only one or two big fires. 

Next came a dramatic surge in the size of the biggest fires. You can see this on the chart by the towering cluster of red bars starting with 2017. During the century before that, the ceiling for extreme wildfires was below 300,000 acres. But in just the last seven years, eight monster fires have shot past that old ceiling. And the biggest wildfires now reach a million acres.  

This explosive surge in both the number and size of California megafires is happening despite all the increased resources and technology the state has been able to throw at them. 

Before we leave that chart, take a look back at it and consider which decade you would pick to live in: Would you pick the current decade crammed with million-acre, town-eating megafires and smoke-choked summers? I sure wouldn't. 

But I also know that fire weather will continue to grow ever more dangerous until we stop fueling it with more fossil fuel pollution. So, as bad as it is today, it can quickly become much more dangerous. 

The megafires that are coming

It can be hard to imagine a significantly different future. As a result, humans often underestimate the rapid changes we are cooking up with our climate pollution. 

California's wildfire crisis provides a good example. Let's step back a few years to the end of 2017. Here's what California's wildfire crisis looked like back then.