The worst disaster in California’s history wasn’t an earthquake, or a fire, or a drought — it was a flood that killed thousands, wiped out mines and ranches, and submerged the state capital, Sacramento. For 43 days, starting in December 1861, California was inundated.

Today, hardly anyone thinks about the floodwaters that turned California’s Central Valley into a vast lake — but it will happen again. “It’s not a question of if, but when,” writes seismologist and disaster expert Lucy Jones in her new book, The Big Ones: How Natural Disasters Have Shaped Us (and What We Can Do About Them). That’s why it’s key for us to know about the disasters in our history, so that we’re not doomed to repeat them on what will certainly be a much larger scale. After all, more than 100 times as many people now live in California as did during that deluge, Jones writes.

“What’s at risk in disasters is not our individual lives, it’s the future of our communities.”

While natural hazards are inevitable, the destruction they wreak is not, Jones says in an interview with The Verge. “We can make choices about how we handle that — but we have to think ahead,” she says. Working at the US Geological Survey, Jones led a team of scientists who investigated the potential catastrophes in California’s future. One of them was a flood, and the team discovered that our existing flood control strategies would be no match for a deluge nearly the size of the one that started in 1861: The disaster would cause more devastation than an earthquake on the infamous San Andreas fault.

After 33 years at the USGS, Jones retired and opened the Dr. Lucy Jones Center for Science and Society, which aims to boost community resilience using science. In her book, she lays out catastrophic disasters in human history from the volcanic eruption that destroyed Pompeii to Hurricane Katrina to the Tohoku quake in Japan in 2011. She tells both the scientific story of how disasters unfolded, and the human story of the communities they struck.

“We have to think ahead.”

Her goal is to teach readers about disasters by drawing them in with narratives, and to address the ways human nature can make it harder to prepare for the future. Most of us assume a big disaster is going to be similar to smaller ones we’ve experienced, which can make us overconfident in our ability to deal with catastrophes — something experts call “normalization bias.” Our tendency to focus on more immediate threats can also come at the expense of preparing for more distant ones — which makes sense, Jones says: “If you worry about the 100-year flood and not about the wolf that’s about to eat your children, your DNA does not get passed down.”

She draws on her experience as a scientist, and as a communicator who helped the public make sense of the destruction in the aftermath of earthquakes. The Verge spoke with Jones about natural hazards, risk assessment, and the disaster that haunts her.

This interview has been edited for clarity and brevity.

I grew up in California, and only learned about the 1861-1862 flood last year. How do you keep the memory of such a major disaster fresh, and make sure that people don’t forget that this could happen again?

It’s very difficult to do. In a natural world, if we hadn’t built all of our flood control systems, we would have smaller floods much more often. When you have the smaller ones, at least you know that flooding is a risk. But you do tend to believe that the risk is what you’ve already dealt with. So, paradoxically, the flood managers who were fully aware of the 1861 flood seemed more willing to say, ‘We’ve got it covered. That isn’t really going to happen again.”

And, like with earthquakes, I find that the people were actually part of a response to Northridge, [a quake that hit part of the Los Angeles area in 1994], are much more overconfident about their abilities to handle the really big one, because they feel like they dealt with the really big one. And that that wasn’t the really big one doesn’t get through.

Hundreds of years ago, we didn’t have the information to be able to think ahead. Now we have more information, and yet we still struggle with the emotional aspect of it, because it doesn’t seem real to us. And that, right there, is the challenge of natural disasters. We know what they’re going to do, we know how to build to avoid the damage, but everything about human nature keeps us from looking forward [for] that really long-term planning. So it requires much more rational, logical thought, and reasoned discourse.

So how do we now wrestle with the human inability to think ahead and also to remember the past?

“Around the world, people are more concerned about tsunami risk than they were before.”

Because of globalization and improved telecommunications, we now have a situation where a flood or a big disaster somewhere else in the world is something we can experience in real time. One of the most striking examples of that was the Tohoku earthquake in northern Japan [in 2011]. I’m sitting in my living room in California, and I can turn on the TV and watch in real time the tsunami wave. And we see the people fleeing from it, from the air. We don’t have enough to save them at this point, but we watch them in real time suffer through this. Now, around the world, people are more concerned about tsunami risk than they were before, I would say.

Fifteen years ago, it was rare to find a person who knew what a tsunami was. But between the Indian Ocean event [in 2004], and Japan [in 2011], and the really direct, emotional experience with the power of telecommunications, we have a really different understanding and experience of it. And that is allowing us to overcome that normalization bias, and it’s part of the reason that we’ve been able to [make progress] here in Southern California [with] getting people to take the risk seriously and doing something about it. For us, it isn’t about tsunamis, it’s mostly about earthquakes.

The book is divided by chapter into case studies of different disasters through history — which one kept you up at night? Which one haunted you?

The 1927 Mississippi flood — the greatest flood disaster in American history. Mississippi is a huge river system that drains the majority of American states. A huge rainfall starting in the fall of 1926 through winter and spring led to failures of the levees protecting the land around the Mississippi river. And 27,000 square miles were flooded and over 1 million people were flooded out of their homes. Over 600,000 people were living in refugee camps.

“What really haunted me ... was seeing how awful we were to our fellow citizens.”

But what really haunted me about it — and made it by far the most difficult chapter to research and write — was seeing how awful we were to our fellow citizens. What happened to African American victims of the flood was appalling, and just the inhumanity of how they were treated.

The Kanto earthquake, which was only four years before that was also — in Japan — an equally horrible turning on neighbors. And it was recognizing that part of the human experience is the need to find a reason why it was the victim’s fault, to blame the victim: “Because if it was the victim’s fault, then I can protect myself by not making those same mistakes.” It’s a subconscious response to fear: “I don’t want that to be able to happen to me.” So you find reasons that it’s the victim’s fault. And at the worst level, you then punish the victim of the situation.

So when you ask what haunted me, I’m an Earth scientist. So the physical part of it was all what I understood and expected going in. What haunted me, and inspired, was sometimes the horribleness of human response, and sometimes the real inspiration of human response. And you see both in those stories.

The book talks about the disconnect between the language scientists use and the language the public uses to talk about disasters. Scientists have their wind speeds for hurricanes, magnitude for earthquake, probability for flood — then the public asks, “Was it The Big One?” How do we bridge that gap — and do we need to?

“I just see people talking past each other so much.”

The stuff I put in this book — none of it is really hard to understand. A high schooler could easily read the book and understand it, maybe even somebody younger. And yet we don’t teach it. And therefore, the public doesn’t have a context within which to be getting the information or having the discussion. So we need better education in science, which does not mean learning a bunch of facts — the other part is to understand how to think about science, the fundamentals of science as a process for learning what’s really true. We don’t teach that.

But then we also need to help the scientists understand that people are looking for a mix: they want the science, but they also want the human side of it. And we need to help the scientists do a better job of being to answer the human questions. I just see people talking past each other so much.

You write about how being a seismologist gives you an unusual perspective on time and that a forecast that a disaster will happen “‘sometime in the next millennium’ sounds not like an evasion, but like a threat.” How has this perspective shaped your own relationship with risk? Are you resigned to it, or have you bought every kind of disaster insurance there is?

“The earthquake’s absolutely inevitable, but chances of it in my lifetime?”

The earthquake’s absolutely inevitable, but the chances of it in my lifetime? Well, the San Andreas is probably going to have [an earthquake] in my lifetime, but the fault I live near probably isn’t. So yes, it’s a possibility, but I just have to keep it balanced because it’s a relatively low possibility compared to other things.

People assume that where I live must be a place that’s really safe from earthquakes, but we moved to a community with really good schools sitting right on top of a significant fault. We were basically gambling that an earthquake wouldn’t happen before the kids got out of high school, and it worked.

Climate change is going to make meteorological disasters more frequent and more devastating, right? What do we need to do to make sure that we’re prepared?

It’s going to be very difficult. People do not sufficiently understand what we are doing to ourselves with this. We need to do everything we can to stop adding carbon to the atmosphere and reduce what’s already there if it’s at all possible. Because more heat in the atmosphere doesn’t just mean it’s warmer and ‘oh I guess I can handle that.’ That means more energy to drive storms, and they are going to be getting worse.

“That doesn’t stop the hurricane from getting stronger.”

So first off, we’ve got to admit it. We can’t talk about nuisance flooding, because high tide is bringing it into your house, without thinking about what that means when the hurricane comes through. One of the big issues in America is that we have a pretty strong tradition of individual land rights: nobody gets to tell you what to do with your own land. We are really struggling as a society to be able to make those big scale decisions.

We need to be changing our attitudes about community, how much we share, to accept that we’re dependent on the decisions of others. We don’t like to do that as Americans either, we so prize our independence. So we philosophically oppose that, but that doesn’t change what’s going to happen. That doesn’t stop the hurricane from getting stronger.

If there were one thing you wanted your reader to take home about this book, what is it?

You have choices. That hazards are inevitable and the disaster is not. We as a society have choices, both what we do individually, but also a choice to work together. The thing that came out of it for me is that what’s at risk in disasters is not our individual lives, it’s the future of our communities, and we can change that if we can work together as a community.