As the Eaton and Palisades fires continue to burn past the more than 38,000 acres they’ve already consumed, the time is right for a conversation about what led up to this disaster.

In the short term, displaced homeowners and renters allege Southern California Edison failed to de-energize its electrical equipment despite weather service warnings about 100 mph wind gusts and extreme fire risks. Bigger picture, scientists know that the fire risks have been decades in the making. 

UC Riverside climate scientist Francesca Hopkins explains how carbon emissions from human activities turn into conflagrations. Hopkins runs the Greenhouse Gas Emissions Lab at UCR, and she has some ideas about making urban landscapes more resilient. 

Q: There are many who understand climate change is making all weather events more extreme, including fires. Can you offer a little more detail about the mechanics of these changes?

A: All of this is related to a phrase coined by Daniel Swain, a climate scientist with UC Agriculture and Natural Resources. The phrase is “hydro-climate whiplash.” This refers to a climate with extreme high precipitation events in winter, followed by extreme droughts.

As a direct result of greenhouse gas emissions from human activities, the atmosphere is warmer than it used to be. 

Greenhouse gases like carbon dioxide or methane create something like a blanket in the atmosphere, trapping heat from Earth’s surface and preventing it from radiating out into space. This makes the planet warmer. 

As the atmosphere gets warmer, it can hold more water vapors. It’s a better sponge than it was before because of the extra warmth. Why is that? There’s a relationship between temperature and the amount of water vapor the air can hold, called the Clausius-Clapeyron relation.

This is an equation that describes a relationship that is exponential, rather than linear. In other words, there is a much larger mass of water in the air than there was before. It’s like when you boil water, the hotter it gets, the more of the water turns into steam. As it gets colder at night, you can see that water goes from gas to liquid when the temperature drops and it becomes fog. 

The atmosphere pulls water out of things that lose it, like plants and soil. And, if you have enough water to create a precipitation event, there will be more rain coming down because there’s more water. 

In Southern California, we had two really wet winters, 2023 and 2024. That gave us a lot of extra plant biomass. But we haven’t had rain in eight months, so now we’re having drought. Our Mediterranean climate has dried out all the biomass, creating a massive amount of fuel for fires to burn. 

Q: Is there anything unusual about the fires we’re seeing now then?

A: I think what’s so unique and scary about these fires is that they’re happening in January. Normally by now we’ve had enough rain to moisten things to the point where fires are less likely. We normally get rains late October, early November, but climate change is increasing the length of fire season, so we’re having fire at a time that used to be so unusual for us. 

We have good evidence that the rainy season has been getting shorter in Southern California. The amount of rainfall hasn’t changed, just the length of the season. This is all very consistent with a warming climate. This is all going to be the new normal. We’ll have more fuel growing and drier fuels. That’s the story with climate change. 

Q: How can we adapt to this new normal and possibly keep these changes from getting worse or causing more damage?

A: We have to rethink everything. We have an opportunity to rethink the future rather than stay stuck in a past that will never come back. 

You shouldn’t build in fire prone areas of course. We have to build smarter, and this is our opportunity to build more compact and walkable cities, not single-family homes and definitely not in the urban wildland interface. Cities are going to think about vegetation management in a way they haven’t before. We have to not build stick frame houses. 

Maybe we should rethink our traditional foods as well, which is one of the hardest things to change. But we know beef has a huge greenhouse gas footprint. Maybe our traditions are not serving us. 

One idea that deserves consideration — we could pay loggers not to make timber for housing but to grow trees just to sequester carbon and keep it out of the atmosphere. We can harvest the trees and then bury them. You can retard decomposition significantly by burying them. We need to be creative. There are so many solutions potentially staring us in the face. 

Reforestation is a solution, as well as protecting the forests we have. Forests don’t grow back the way they were even when you replant the trees. If we can create monetary value in forests by leaving the trees there instead of extracting value from forests by taking timber out for building homes that burn, that would be better on so many levels. We need to think differently.