NEW YORK (AP) — In the opening scene of American writer Kim Stanley Robinson’s "The Ministry for the Future," a heat wave combined with a breakdown of the electrical grid in India kills 20 million people. The devastation causes the world’s nations to unite to combat climate change.

Scientists have long warned that the world will experience more intense extreme weather events like heat waves, storms, floods and droughts. But what once seemed like the realm of fiction is now discussed as a possibility, even an inevitability.

Warning about an "extreme of extremes" or the "Other Big One," a play off the California reference of a big future earthquake, can be fraught. After all, nobody can say for sure when a weather catastrophe may happen. But in the last few years, the planetary ingredients needed for a massive disturbance have been building. And alarm is growing.

"The risk is that people just think you are exaggerating," said Daniel Swain, a climate scientist with the California Institute for Water Resources. "It’s the ‘Boy Who Cried Wolf’ problem. Sometimes wolves are real. If it’s outside the door, wouldn’t you want to know?"

The risks have been known, and building, for over 150 years

In the 1850s, while living in Seneca Falls, New York, amateur scientist Eunice Newton Foote did a series of experiments that put different substances, including carbon dioxide and moist air, inside glass cylinders and left them in the sun. What she found was extraordinary: cylinders with carbon dioxide, a greenhouse gas that is released when coal, gas or oil is burned, heated up faster and took longer to cool after the sun went down.

Fast-forward: Today, Earth is being heated by massive amounts of greenhouse gases being pumped into the atmosphere, leading to a gradual rise in average global temperature. That increase, 1.44 degrees Celsius (2.59 degrees Fahrenheit) warmer in 2025 compared to the early 1800s, leads to more frequent, and more intense, extreme weather events.

The country that has released the most greenhouse gas, and thus contributed most to climate change, is the United States. President Donald Trump has called climate change "the greatest con job ever" and referred to climate policies as a "Green New Scam." He has also said U.N. climate predictions were made by "stupid people."

Recent disasters underscore the stakes

Australia’s "Black Summer" wildfires in 2019 and 2020 scorched 19 million hectares (over 46 million acres). In 2022, flooding in Pakistan left a third of the country under water. Hurricanes Milton and Helene in 2024 ravaged parts of the southern United States. Texas floods engulfed young campers in the year before the article. Los Angeles wildfires chewed through entire neighborhoods, and Typhoon Kalmaegi walloped Vietnam and the Philippines. These are just a few examples of the kinds of events that scientists say are becoming more common.

Sarah Perkins-Kirkpatrick, a climate scientist at Australian National University, said she had a "come to Jesus moment" when she realized that constant extreme weather events wouldn’t stop even if the world immediately reached net zero. Many countries and major companies have net-zero targets for 2050 or beyond, but carbon dioxide can remain in the atmosphere for hundreds of years.

"It’s the issue of the frog in the boiling water," Perkins-Kirkpatrick said. "If we get used to bracing ourselves, are we going to notice?"

Robinson, whose book was published in 2020, says if he were writing today he would include a chapter on wildfires, which have become larger and more destructive. He believes the risks of catastrophe have increased, though the potential heat disaster in India he wrote about would arguably be less likely today thanks to less reliance on the grid and use of solar power.

The science is clear, but so is the denial

Sonia Seneviratne, a Swiss climatologist who vice chairs a working group of the Intergovernmental Panel on Climate Change, likens climate risk to smoking and lung cancer: people who smoke won’t necessarily get lung cancer, but the chances are higher, and similarly the risk of massive extreme events rises with every tenth of a degree.

"If such an event happened, I could already see the criticism of people saying, ‘Climate scientists didn’t tell us.’ But we did," Seneviratne said.

Lucy Jones, a seismologist and author of "The Big Ones: How Natural Disasters Have Shaped Us (and What We Can Do About Them)," has spent years working to prepare communities for disasters. In 2014, while with the U.S. Geological Survey, she worked with Los Angeles Mayor Eric Garcetti’s administration on an initiative that produced widespread retrofitting and earthquake preparedness in LA and later other California cities. Two years later, she formed a nonprofit that advises on preparing for earthquakes and other disasters.

"Climate denial is one way of coping," Jones said, noting that people rationalize by thinking they won’t believe it’s true so they’ll feel safer.

Fiction and reality blur

In the 2004 film "The Day After Tomorrow," Jack Hall (played by Dennis Quaid) is a climate scientist who, speaking at a U.N. climate conference in Delhi, urges major reduction in greenhouse gas emissions. In the film, melting polar ice halts the North Atlantic Current, leading to giant cyclones, massive hailstones, heavy flooding, tornadoes, and a big freeze so cold that anybody outside dies.

In the 2021 satire "Don’t Look Up," two astronomers played by Leonardo DiCaprio and Jennifer Lawrence discover a giant comet heading toward Earth and try to spur action to avoid annihilation. The U.S. president, played by Meryl Streep, says "At this exact moment, I think we sit tight and assess" after learning the comet is heading straight toward Earth, and at the end almost everybody dies.

But the reality, scientists say, may be closer than fiction. More than half of all greenhouse gases produced by humans throughout history have been released into the atmosphere over the past 50 years. In January 2022, the U.K. Climate Risk Assessment said there was a 0.02% chance of 40C (104F) or above heat before 2040. In summer 2022, parts of the U.K. topped 40C.

According to the National Oceanic and Atmospheric Administration, between 2023 and 2025, 84% of the world’s corals suffered the expelling of microscopic algae in response to heat stress. The Amazon rainforest is at risk of a tipping point; the debate today is when, not if, the Amazon will release more carbon dioxide than it holds. Persistent drought, large wildfires and deforestation to make way for cattle have degraded swaths of the Amazon forest in recent decades. This year’s El Niño is expected to be the strongest ever recorded.

A call to face the worst

Tim Lenton, climate science professor at the University of Exeter, said: "We need to be talking about some of the worst things that can happen. It’s natural to think that some bigger shocks are on the way."

That sentiment echoes the growing alarm among scientists who argue that the window for action is narrowing, and that the public and policymakers must confront the possibility of catastrophic events—not as fiction, but as a real and present danger.