Can Japan handle a heat wave and natural disaster at the same time?

Hiroaki Nishino witnessed the violent whims of nature firsthand in September 2019, when a powerful typhoon packing winds of up to 200 kilometers per hour made landfall in Chiba Prefecture.
Four years earlier and with the memory of the 2011 Great East Japan Earthquake still fresh in his mind, the freelance editor had built a disaster-ready home in the city of Futtsu overlooking Tokyo Bay.
But the storm in 2019, Typhoon Faxai, was nothing like what he had experienced before, Nishino recalls. The wind was so strong that his home shook and creaked all night as if it were being hit by earthquakes nonstop.
“I could not sleep a wink that night,” he says. “I honestly feared that my home would be torn to pieces.”
While the sturdy wooden house nonetheless survived without damage, apart from an exterior window shutter being yanked from its guard rails and blown away by the strong gusts, tens of thousands of homes in the seaside community on the Boso Peninsula and the wider prefecture weren’t as lucky.
The typhoon also knocked over 2,000 utility poles, mostly in Chiba, leaving hundreds of thousands of households without power for days and even weeks for some, while 140,000 households lost access to water. That would be a crisis at any time, but it was made worse by what followed — temperatures as high as 38 degrees Celsius, according to Nishino.
At least four people likely died from heatstroke because they were unable to use their air conditioning units (such deaths are also notoriously hard to count).

A large-scale disaster in the middle of a heat wave sounds like living hell. Yet the scenario has been on the minds of many since early August, when the government issued its first-ever Nankai Trough megaquake alert, right when the nation’s energy demand was peaking and people were relying on their ACs to cope with scorching temperatures.
This raises the question: Is Japan prepared for a big disaster, be it a megaquake or a super typhoon, amid extreme heat?
“I feel that the number of municipalities in Japan that are fully prepared for compound disasters (of heat and natural disasters) is still really limited,” says Takako Izumi, a professor at Tohoku University who specializes in disaster risk reduction. “This abnormal heat we have been experiencing for the last few years … it presents us with a huge new challenge.”
Izumi says securing an alternative energy source is becoming a more important part of preparing for a summertime disaster, especially when it comes to protecting higher-risk people from the dangers of heatstroke. Indeed, the Environment Ministry has advised people to stay in a cool place and not shy away from AC use, especially on days when a heatstroke alert is issued — a common occurrence across much of Japan this July and August.
Many public schools in Japan are turned into emergency shelters when a disaster strikes. But not all of them are equipped with adequate cooling capabilities, which could prove fatal for evacuees if there is also a heat wave.
According to education ministry data, as of December 2022, about 65% of some 30,000 schools designated as disaster shelters were fitted with AC. But the percentage included schools where just one room — be it a classroom or a conference room — was outfitted with cooling equipment.

A separate survey by the ministry found only 11.9% of public elementary or junior high school gymnasiums had AC installed as of September 2022. By prefecture, Tokyo’s school gyms had the highest ratio, at 82.1%, while for many other prefectures it was less than 10%.
Even fewer schools are equipped with ACs that can keep running during a blackout.
With disaster preparedness in mind, Tokyo’s Adachi Ward has introduced gas-powered ACs at nearly all of its school gyms.
Satoshi Okada, a ward official in charge of school facilities, explains that the ward installed ACs at about 100 school gyms in 2020. Before that, the gyms had no AC, though classrooms and other rooms in Adachi’s schools had installed them gradually since the late 2000s.
The gas-powered ACs still need a bit of electricity when they start running, much like how a gas-fueled car needs a battery to get its engine started. In the event of a disaster and an ensuing blackout, a battery in the outdoor unit of the AC system generates enough electricity to get the AC working. After a while, air can be cooled just with propane gas.
The schools in Adachi stock enough propane gas cylinders on their premises that ACs can run for three days, officials say, noting that the ward has been arranging meetings with community leaders near the schools to explain how they can make the switch to the propane gas in times of disasters.
The ward has benefited greatly from a subsidy from the Tokyo Metropolitan Government, which financed about a quarter of the ¥8 billion-plus ($55 million) 10-year leasing fees.

At the time the ACs were installed, the ward had no choice but to opt for gas power, Okada says, given the limited capacity of renewables such as solar to meet energy demands at the schools.
There’s still limited research on how a mix of heat and a disaster-induced power cuts plays out, says Yoshihiro Okumura, professor at the faculty of societal safety sciences at Kansai University.
But based on an analysis of newspaper accounts of torrential rain that hit wide areas of western Japan in July 2018 and 2019’s Typhoon Faxai, Okumura says power outages resulted in deaths from heatstroke of at least one in the former and four in the latter. Even in cases where the official cause of death is put down as a stroke or a heart attack, heat stress could be an underlying factor, he says, pointing to the possibility that summer disasters resulting in extensive blackouts could lead to further deaths.
Okumura hopes that the private sector will play a bigger role in making the country more disaster resilient, saying public-sector resources for anti-disaster measures are already stretched to the limit. It would be ideal if private-sector companies, such as property management firms, could come up with solutions for residents of condominiums, he says.
“For example, if there’s a blackout, it may be tough to supply emergency power to an entire condominium with 100 or 200 units, but a condo management firm may be able to open a communal cooling lounge where residents can drop by and cool themselves for a few hours,” he says, noting that he has not heard of any examples of condos offering such services so far.
“I think the private sector would be keen to do it if they knew there’s enough demand and if it leads to more business.”
Disaster resilience is crucial for hospitals, where even a short suspension of care could cost people’s lives. Sohei Hikosaka, a nurse at the Hamamatsu University Hospital who studies disaster medicine, says that many hospitals in Japan have learned from the experience of the 2011 Tohoku disasters and created contingency plans — though many issues remain.
In 2019, Hikosaka and others surveyed 73 hospitals and maternity clinics in Shizuoka Prefecture about how they responded to Typhoon Trami, a powerful storm in late September and early October the year before that hit the prefecture particularly hard and caused a blackout affecting 710,000 households in the prefecture.

The typhoon forced hospitals, dialysis centers, pharmacies and other medical institutions to shut down or postpone some services. Hikosaka’s survey found that 49 of the 73 facilities suffered a power outage, and many remained without power for over 12 hours. While nearly 70% of the respondents were equipped with private generators, some reported running out of gas or having trouble getting them to work.
One hospital lost power while a doctor was performing a cesarean section. In response, hospital staff shone a flashlight on the mother and managed to have the baby delivered, according to the survey report compiled by Hikosaka.
Hikosaka, who is also part of a unit of trained medical professionals dispatched to disaster zones to offer emergency care, says hospitals are increasingly changing their stance on disaster response. Before, their basic policy was to move patients out of hospitals hit by a disaster and transport them to institutions in unaffected areas.
“When you think about the scale of damage expected from a megaquake such as the Nankai Trough earthquake, it is not realistic to move severely ill patients out of the disaster zone,” Hikosaka says. “With a disaster that extensive, the number of emergency helicopters and hospitals accepting patients would be very limited. So the emphasis has shifted to how disaster-hit institutions can do damage control themselves.”
The health ministry has designated 776 hospitals as “disaster base hospitals,” which, when a disaster occurs, not only engage in the initial emergency care of injured patients but also offer support to other hospitals in their areas that have sustained damage.
These hospitals are required to have a private power generator and enough fuel for three days, through which they are expected to generate at least 60% of the power needed for normal operations.

Some forward-looking hospitals are preparing for a disaster scenario in the form of “a disaster reduction game,” Hikosaka says, noting that they give staffers a chance to think beforehand about what services to keep and what others to cut if it becomes necessary to shed 40% of the power they use.
“They may discuss postponing scheduled surgeries, halting outpatient services, limiting MRI scans to the most pressing cases or stopping some of the elevators,” he says. “But institutions preparing this way are still very rare — accounting only for a fraction of the nation’s hospitals.”
As institutions weigh how to deal with the combination of a major heat wave and another natural disaster, there are some steps that individuals can take.
First and foremost, water and food are the most important necessities, especially if a huge disaster like an inland Tokyo quake strikes, argues Naoya Sekiya, a disaster information expert and professor at the University of Tokyo. A government panel has estimated such a quake below the metropolis could flatten 175,000 homes and kill up to 11,000 people through the destruction of buildings alone.
For individuals, it’s important to stock up on enough water to allow for 2 to 3 liters per person per day for seven days, as well as seven days’ worth of food, he says.
“Water is the most essential resource to avoid heatstroke (from dehydration),” he says.

In Chiba, Nishino recalls that backup power — thanks to two engine-powered generators he had owned for farming and a portable battery with solar panels a friend brought over — made a huge difference. He used them to freeze bottles of water and give them to neighbors without a functioning freezer or fridge. He also cooled the vegetables he had grown in the garden and shared them with the thankful neighbors.
“You start to miss fresh vegetables (after eating emergency food for a while),” Nishino says. “If you grow even a few vegetables in your garden or your planters, it will not only help you survive a disaster but also enrich your life.”
Following the disaster, he installed solar panels on the roof of a shed and the balcony of his home, with these being enough to meet the family’s energy needs. Nishino, who has published a book recounting his experience and sharing tips on how to make homes resilient, is not thinking of ditching his electricity provider Tokyo Electric Power Co. completely, but can now go off the grid if he wants to.
Considering that climate change, which is primarily caused by the burning of fossil fuels, is making extreme weather more frequent and intense, a fundamental solution requires a review of current lifestyles and for nations including Japan to move away from energy sources that contribute to global warming, says Yoshiteru Murosaki, a disaster risk management planning expert and professor emeritus at Kobe University.
“With global warming, our ecosystem is changing and causing more localized torrential downpours,” he says, noting that, in recent years, the frequency of heavy rainfall has increased in Japan. “Elsewhere in the world, wildfires are running rampant, everywhere from Oahu in Hawaii to Chile to Nice in southern France.
“When you think about disasters, we think of quakes and heavy rain. But a bigger disaster is creating an environment on Earth where our survival is threatened. So everyone, including those involved in disaster reduction, must work much harder to curb global warming.”

Disaster survival tips
Nishino, author of the 2020 book “Hinanjo ni Ikanai Bosai no Kyokasho” (“A Disaster Prevention Textbook for People Not Going To Emergency Shelters”), offers the following advice on how to prepare for and cope with a disaster:

Before a typhoon or torrential rain: