How to beat Japan’s summer heat in ways better for the planet

As summers get hotter across the world — and Japan potentially faces its hottest summer on record — we’re met with a paradox: To stay cool, it seems we’re compelled to consume more.

We consume more energy to cool our houses, and buy more stuff to try and combat the heat. That’s especially true in Japan, where consumerist habits and the changing of the seasons are close allies.

As effective as some of the many summer products may feel, the overconsumption they signify is the very thing that got humanity here in the first place. Manufacturing and the production of plastic, along with our insatiable appetite for food, speed, stuff and travel, and the resulting waste, all contribute to the greenhouse gas emissions making the world dangerously hot.

So at this moment, when the planet’s ill health is in sharpest relief, it’s worth considering real ways to minimize cost and consumption — ranging from the traditional to the technological — without succumbing to dangerous heat. Here are some ways to stay cool that are better for the planet.

Cooler you

Walk down a city street in July or August and you’ll see an abundance of gadgets and accessories dangling from pedestrians. Sun parasols and hand-held electronic fans are ubiquitous. Among the newer trends are cooling necklaces — plastic rings that you put in your fridge or freezer which act as a wearable ice pack — and devices that look like over-ear headphones which contain fans that blow air up toward your face.

These cheap plastic cooling products flooding the market might offer a quick fix but they aren’t necessarily sustainable. But there’s good news: Many of them are essentially modern versions of older personal cooling methods.

Portable hand-held fans are, for example, an evolution of sensu (folding fans), except they require batteries and create e-waste, so you could just stick to the paper version if you’ve got one lying around.

The ice necklace, meanwhile, mimics a trick from previous generations in Japan: On hot days, mothers often wet a tenugui towel and wrapped it around their child’s neck.

Ran Nomura, who runs the Instagram account @zerowaste.japan, lists off a host of ways the durable and versatile tenugui, which many people have in their homes, can be used to cool one’s body.

There’s an icy version of the water-soaking trick: Take an ice pack — perhaps one foisted upon you by a grocery store employee to keep your food chilled — fold it into a tenugui, and wrap it around your neck or head. You could also stick the towel under your hat so it covers your neck and shoulders from the sun; in lieu of a hat, wrap the towel around your head.

Staying hydrated in summer is necessary to avoid heatstroke. Simply carrying a water bottle with ice around cuts down on plastic waste, while also providing a source of cold, however briefly.

With a bit of planning, you can keep it topped up while you’re out. Mymizu is an app with crowd-sourced locations of free public and private drinking water, discouraging users from reaching for another plastic bottle from a vending machine.

“Really at the heart of it is overconsumption of plastic,” says co-founder Robin Takashi Lewis, “So we address the root of the problem — the consumption point.”

Fabrics are also worth paying attention to. Fast-fashion products that purportedly block out the sun are made of cheap synthetic materials that don’t last and will naturally encourage more consumption. In fact, many of the special summer clothes marketed in Japan are made of synthetics, because chemical treatments are quicker drying and better at moisture wicking than, say, cotton — but generally speaking, they also trap heat.

You might look instead for lighter, breathable materials like cotton and linens in lighter colors, which let air flow through. Counterintuitively, merino wools are also great in summer. Although they are often more expensive than synthetics, natural fibers last longer, and once they’ve reached the end of their lifespan they biodegrade more quickly and don’t release microplastics.

Cooler home

While some may feel they are able to deal with the heat without air conditioning, for the vast majority it’s not realistic or advisable to forego it on a day when it’s already 30 degrees Celsius at 8 a.m. But there are ways to make the unit work more efficiently — cutting down on costs and your carbon footprint.

Since you need curtains anyway, opt for ones that are double layered and block UV rays. (Although these are typically made of synthetics, cotton and linen options are available.) Consider getting bamboo shades for outside your house or keeping the curtains drawn during the hottest part of the day, especially on windows facing the direction of the sun.

Circulators can also move air more efficiently around the house so that the air conditioner can be kept at a higher temperature. And use appliances that generate heat, like stoves, rice cookers, kettles and hairdryers, in the morning and evening, not during the hottest times of day, when the air conditioner already has to work harder to cool the house.

Another approach, says Nomura, is to consider the number of people being cooled per air conditioner unit. Her family of four gathers in one room with one unit on, rather than all sitting in separate rooms with separate units running. And as best as she can, she avoids running it just for herself. If she needs to work and no one else is home, Nomura prefers to set up somewhere that is already air-conditioned, like a coworking space or a cafe.

This communal reuse mentality can apply elsewhere: Rather than buying a sun parasol when you’re short on one, rent one from services like iKasa, Lewis suggests.

If you really want to level up, one of the best things you can do for your home, says Greenpeace Japan’s climate and energy campaigner Kazue Suzuki, is to invest in better insulation and sealing. She cites a consumer report that says 90% of homes in Japan today are uninsulated or poorly insulated, meaning hot air leaks into the house and cool air leaks out. (The reverse is true in winter.) She recommends installing double-pane windows.

Although it’s not a cheap hack, the Japanese government is offering subsidies for window retrofitting.

Cooler mind

Incredibly, there may be ways that the mind can trick itself into feeling cooler — psychological cooling, if you will.

Researchers from Kyoto Prefectural University’s Graduate School of Life and Environmental Sciences surveyed residents of Kyoto to study old-fashioned, environmentally friendly ways that people cool themselves. Those surveyed said they sprinkled water on the streets and ground (uchimizu) and used sudare, or bamboo blinds, to combat the heat. But there were other habits, including switching to cool colored interior decor; cool-feeling music; cool incense and aromas; and fūrin, or wind chimes.

Naoki Matsubara, one of the researchers, says by email that these were employed for “nonthermal reasons,” like “gaining a sense of coolness, feeling the season and pleasant sound.” Respondents who performed many of these activities tended to use air conditioning for shorter periods of time.

“Residents are thought to tolerate a less comfortable thermal environment by feeling a sense of satisfaction and comfort from the cool and seasonal sensations they get from actively performing coolness-getting activities in their daily lives,” he writes.

Still, he doesn’t recommend seeking psychological coolness to curb air conditioning use on days that are extremely hot, when you need to pay attention for signs of heatstroke.

Cooler planet

Readers will have likely seen men walking down the streets in the blaze of Japanese summer wearing medium-weight long-sleeved jackets that puff up around the body — a bubble of air created by fans built into the device and blowing inward.

Sft Laboratory, the company that pioneered this construction work gear, says that its jacket has a lower carbon impact than the use of air-conditioning for the same number of workers, because it cools the body directly, rather than the surrounding air. In 2017, the company received the Environment Ministry’s Commendation for Global Warming Prevention Activities, citing that the jackets reduced carbon dioxide emissions by 7 tons in the month of August for 50 people working in a space of 1,000 square meters.

A representative from the company estimates that with eight hours of use a day in hot months, a jacket can last two to three years. But then what? People can seek out one of the specially designated rechargeable battery recycling centers that Sft Laboratory is a member of, or figure out how to throw the jacket out according to their local garbage regulations.

Indeed, one of the issues with the myriad cooling products on the market is the lack of clarity around how to dispose of them.

Japan is often lauded for its strict waste management system and the hyperconscious citizenry that adheres to it. But its impressively high rates of recycling plastic (87% in 2021) is misleading: What Japan calls “thermal recycling” is considered internationally to be energy recovery — by another name, incineration.

These summer cooling products are hardly the worst offenders in plastic-happy Japan — but even in an ideal world of perfect recycling and disposal, the solution lies beyond picking the right bin to throw out the stuff we’ve accumulated.

The old adage “reduce, reuse and recycle” should really be in that order, says Mymizu’s Lewis, as an overreliance on the consumption of plastics means using more crude oil.

“Recycling should never be the default; it should be the last resort,” he says. “We can’t recycle our way out of this problem.”