The Most Underrated Sci-Fi Movie on HBO Max Reveals a Controversial Branch of Pseudoscience

Since time immemorial, humans have prayed to the gods to change the weather — usually in the form of dances to summon rain to Earth. But in the Japanese animated sci-fi movie, Weathering with You, director Makoto Shinkai flips that idea on its head, featuring a so-called “Sunshine Girl” who can pray away the rain and make the sun appear again.

Spoilers ahead for Weathering with You

But when the Sunshine Girl, Hina, and her friend, Hodaka, get together, they collectively change the weather for good — and alter the fate of the world. For months and even years on end, Tokyo is besieged with a deluge of extreme rainfall as their weather manipulation goes awry. You’ll have to watch the movie to find out what happens, but, suffice to say — there are no real-life Sunshine Girls.

Yet, the movie’s sci-fi plot alludes to two real-world scientific phenomenons events — and we should take a closer look at them.

First: climate change is making the threat of severe rainfall more likely. Second: people are responding to climate change by trying to control the weather — yes, really. But can we actually stop a storm as in Weathering with You? Or are there more grounded ways we can save the world before we try to change the weather?

Reel Science is an Inverse series that reveals the real (and fake) science behind your favorite movies and TV.

How does climate change make extreme rainfall more likely in cities like Tokyo?

Whether Makoto Shinkai knew it or not, he made a pretty intriguing sci-fi climate change movie. The months of nonstop rainfall and flooding Tokyo endures in the movie can be read as a metaphor for the increase in extreme rainfall — and flooding — which cities across the globe will face in a warming world.

“Temperatures are rising. And what that does is basically supercharge our water cycle,” Alison Branco, New York Coastal Director and Acting Director of Climate Adaptation for the nonprofit The Nature Conservancy, tells Inverse.

Jonathan Winter, an associate professor in the Department of Geography at Dartmouth College who studies extreme rainfall, tells Inverse that a warmer atmosphere can hold more water. Imagine a cloud as a bucket that can only hold a gallon of water under normal conditions, but under warmer weather, it can now hold two gallons of water. Suddenly, double the amount of normal water is falling into your city.

“So, when you get the right condition, you can get more water falling out of the sky,” Winter explains.

But Winter adds that while annual precipitation might increase in humid areas of the world — along with short bursts of extreme rainfall — we certainly won’t go months on end without seeing a clear sky as in the movie.

Likewise, Branco says usually only certain parts of a city will experience flooding in the aftermath of severe rainfall — so we won’t see an entire city deluged with rain a la Weathering with You.

“Most places, it's just a block or a few blocks or you know a small portion of the city that's actually flood-prone. But there are very few places where it means the whole city is doomed,” Branco adds.

Can we use weather modification to stop a storm?

There are no real-life Sunshine Girls, but American scientists have been trying to modify the weather for the better part of a century since the 1940s. Another term for weather modification is “cloud seeding” and it basically involves “seeding” clouds with particles to increase precipitation—either rainfall or snow.

Scientists have also used the technique to try to disperse fogs, suppress hail, and even weaken hurricanes with the US government’s infamous — and unsuccessful — “Project Stormfury.” You can find a full list of recent US weather modification efforts in the NOAA library here, but many other countries — such as China and Russia — also have cloud seeding programs.

Robert (Bob) Rauber, professor of atmospheric science at the University of Illinois Urbana-Champaign, previously told Inverse how he defines weather modification:

Weather modification is the introduction of some sort of material — typically either silver iodide tiny little salt particles — into a cloud to attempt to change the amount of precipitation coming out of the cloud, or characteristics of that precipitation, such as changing the size of hail.

There’s just one problem: weather modification has a shaky track record. Hugh E. Willoughby, tells Inverse that weather modification to increase precipitation is “kind of pseudoscience.”

“It's 20th-century ideas, dressed up with 21st-century gizmos,” Willoughby adds.

Willoughby previously served as director of NOAA’s Hurricane Research division and conducted cloud seeding research on the Florida Area Cumulus Experiment (FACE), which sought to modify clouds over the Everglades to increase rainfall. But he’s since turned a new leaf and now believes that there is little scientific evidence to support cloud seeding’s success.

“I talk about my skepticism honestly because nobody's ever been able to show that they made it rain,” Willoughby says.

During his research with FACE, Willoughby says the rainfall they were trying to produce would have happened naturally anyway, since it was already occurring on days when heavy rainfall was expected.

“We were making it rain 20 percent more on days, principally when it would naturally rain a lot. So there was no way to distinguish the expected results of seeding cloud seeding from what happens naturally,” Willoughby says.

Most cloud-seeding efforts try to make more precipitation happen, but there have been efforts to try to suppress hail — i.e., reducing the size and amount of the hail — using sound, such as the hail suppression experiments in Colorado in the 1970s or more recently in Alberta, Canada.

But Frank Marks, director of NOAA’s Hurricane Hurricane Research Division, tells Inverse both FACE and the Colorado experiment “were not conclusive that the cloud seeding or sound really had a statistically significant impact.”

There is a little more scientific evidence to support cloud seeding to disperse low-lying radiation fog, which airports have used to ensure smoother takeoffs and landings. It’s plausible, Willoughby says, that you could use cloud seeding to disperse the fog and bring back sunshine — so kind of like the Sunshine Girls in Weathering with You. This technique could be useful on a cloudy day in an area that relies on renewable energy, such as a solar farm in California. But it would probably take a lot of silver iodide and wouldn’t be cost-effective.

In more recent decades, the Chinese government has claimed to use cloud seeding to divert storms prior to the 2008 Beijing Olympics by releasing rain outside the city, and, in other cases, using the technique to clear up air pollution and produce blue skies. But both Willoughby and Winter are skeptical of such approaches.

Winter says the idea of using cloud seeding to divert storms upstream makes sense — in theory — but adds that if there’s enough water and motion in the atmosphere, then it doesn’t matter how much cloud seeding you attempt to try to divert the storm.

“It doesn't seem like that incremental seeding of clouds would do much of anything,” Winter says.

How should we adapt to extreme rainfall?

In Weathering with You, the entire city of Tokyo experiences persistent flooding for months due to severe rainfall. In one memorable scene, a man living in a sub-basement dwelling opens his window, causing water to flood his apartment up to his ankles.

In real life, scientists expect more and more of these extreme rainfall and flooding events to occur in the future as a result of climate change — in fact, we’re already seeing them happen now.

Last August Japan ordered more than 300,000 people to evacuate due to floods and a few months later, Tokyo experienced severe floods that injured 60 people. And it’s not just in Japan. The year before, the remnants of Hurricane Ida flooded New York and caused dozens of deaths across four states.

But experts caution against trying to use weather modification or geoengineering to stop such extreme weather events, such as trying to combat drought and low water levels through cloud seeding in the western U.S.

“We have been inadvertently modifying the planet's atmosphere for centuries,”

For one: the limited evidence in their favor makes them an unreliable approach. If we can’t conclusively link weather modification attempts to changes in weather, then we open the door to suspicion and even misinformation — like the accusations that the 2022 floods in Australia were caused by cloud seeding.

“In my opinion as a federal scientist, my biggest fear with the weather modification approaches is in dealing with liability,” Marks says.

“We have been inadvertently modifying the planet's atmosphere for centuries, and look where that has gotten us,” he adds.

Instead of banking on moonshot solutions to climate change or hoping for a miracle — the real-world equivalent of “praying away the rain” — Branco says cities need to step up now to adapt and prepare their communities for extreme rainfall. She says cities need to get in place emergency warning systems and prepare certain communities that may need to move to higher ground.

But there are also ways we can build more flood-resilient infrastructure, such as planting trees or bolstering natural green spaces in cities to serve as “rain gardens’” that can soak up stormwater runoff, easing the burden on the city’s water treatment facilities and old pipes. As far as more high-tech solutions go, Branco would favor cities develop better elevation modeling maps to understand the flow of water trajectory during storms.

“So if I was going to spend a lot of money on high-tech solutions, I would focus on that instead of trying to stop the rain from happening in the first place,” Branco says.

Weathering with You is streaming now on HBO Max.