Just how green are Japan’s trains?

In the national quest to go carbon neutral by the year 2050, reducing the 17.4% of Japan’s carbon dioxide emissions that come from the transportation sector will be a crucial piece of the puzzle.

Already, there’s been some positive steps in that direction.

According to data from the Ministry of Land, Infrastructure, Transport and Tourism, the sector’s carbon dioxide emissions have declined annually since 2001, and are now 70% of what they were at their peak. Meanwhile, government policies and industry initiatives have made substantial progress solving environmental problems in areas ranging from harmful particulate matter and vehicle recycling.

Still, Japan’s public transportation system, while undoubtedly greener than car and air travel, will still require drastic changes to reach carbon neutrality — including shifts that, as of now, experts and industry insiders can hardly imagine possible.

And the stakes are clear: The climate crisis is already causing extreme heat waves, deadly typhoons and reduced snowfall across the country.

“We know that we need to go carbon neutral,” says Masaru Kumai, a senior manager at the Foundation for Promoting Personal Mobility and Ecological Transportation (ECOMO). “But no one has exactly figured out how to do it.”

All solutions begin by looking at Japan’s impressive network of trains and subways. Per data from Central Japan Railway (JR Central), one passenger traveling between Tokyo and Osaka on the Nozomi service of the Tokaido Shinkansen will emit 4.2 kilograms of carbon dioxide. That figure is about one-twelfth of the emissions of a passenger on a typical Tokyo-Osaka flight.

Meanwhile, driving a gas-powered Toyota Camry consuming 6.1 liters of gas per 100 kilometers on the highway to Osaka, a roughly 500 km distance, would emit over 120 kilograms of carbon dioxide — about 30 times more emissions than taking the shinkansen.

But Japan’s trains are far from achieving carbon neutrality. Generating electricity for trains requires power: burning coal, crude oil or natural gas, or generating energy from solar, wind, nuclear, geothermal and other sources. And the Fukushima disaster, which drastically reduced public support for nuclear power, meant that until 2019, Japan was more reliant on fossil fuels than it was before 3/11, essentially setting the country back a decade in the push to decarbonize.

According to calculations by the Institute for Sustainable Energy Policies based on government data, Japan generated 72.4% of its electricity from fossil fuels in 2022, and just 22.7% from renewable resources.

Unless Japan has a path to generating 100% of its electricity from sustainable sources by 2050, it has a poor chance of going carbon neutral, in the transportation sector or anywhere else.

As a result, although rail makes up just 4.1% of Japan’s emissions in the transportation sector, they still add significant amounts of carbon to the atmosphere. The biggest railway company emitters are East Japan Railway (JR East), West Japan Railway (JR West) and JR Central — each responsible for over 1 million tons of carbon dioxide annually.

However, Japan’s rail companies have already pushed down their emissions by substantial margins since 2013, demonstrating progress in the path to carbon neutrality and paving the way for Japan’s transit sector as a whole to achieve such a goal.

Major rail companies have aggressively introduced measures such as energy-saving railway cars, power storage devices for energy generated from braking, and shifting electricity sources to green energy. At the beginning of 2022, JR East’s emissions were down 15% since 2013; JR West’s 29% since 2013; JR Central’s 23% since 2013; and Hankyu-Hanshin Holdings' railway operations 42% since 2017.

Tokyu Railways leads the pack, however, as the first railway to operate all of its lines with 100% renewable electricity, which it has done so since April 2022. Tokyu has purchased enough renewable energy certificates to power its seven lines through Japan’s Feed-in-Tariff policy, which allows businesses to guarantee the purchase of their electricity from green energy providers. Tokyu states that the emissions savings from this achievement are equivalent to the average annual emissions of 56,000 Japanese households.

Meanwhile, JR East has put a strategy in place to reduce carbon dioxide emissions by 50% by 2030 and reach net zero by 2050. Toru Inoue from the company’s corporate communications department says that 90% of the company’s carbon dioxide emissions come from generating electricity, of which nearly half comes from a power plant in Kawasaki that uses natural gas as fuel.

“We need to make progress on decarbonizing our thermal power plant and introducing renewable energy sources in order to reduce emissions,” Inoue says.

The railway giant says it has introduced a stock of railway cars that reuse the kinetic energy generated during braking, switched diesel cars to diesel hybrids, installed LED lights and energy-efficient air conditioners, and increased the use of wind, solar and geothermal energy sources, mainly in Tohoku. JR East is also developing a train that uses hydrogen-powered fuel cells and storage batteries, which started demonstration tests on the Tsurumi and Nambu lines in March 2022.

“We have set our targets on the premise that technological innovation, such as the development of hydrogen-powered energy plants, will continue to advance, and we believe it is essential to respond flexibly to these developments,” adds Inoue.

Even though railways emit less than other forms of transportation, this efficiency makes their decarbonization more important, not less — experts say that without reducing rail emissions or getting them to zero, countries will not be able to fully benefit from any shift from automobiles to rail transport.

While Japan’s major metropolitan areas are known for their robust transit systems, cars remain a primary mode of transportation in midsize cities.

Indeed, shifting the public from car use over to public transit is one of the two major policy objectives taken by regional centers, with the other being improving road and traffic conditions. Also garnering attention are the emerging approaches of walkability and “micromobility,” which promotes light rail, buses, bicycle lanes and bike sharing for local transit instead of cars.

“Utsunomiya city is one example that caught my interest because of their investments in walkability and micromobility through the creation of their new light rail system,” says ECOMO’s Kumai.

Utsunomiya's newly developed tram line, built from scratch, connects Utsunomiya Station to the city's eastern industrial district and is scheduled to begin operation this August.

Sendai has also made progress in reducing emissions through the launch of the relatively new Tozai subway line, which opened in 2015. Katsura Sato, director for Sendai’s transportation policy section, says that as a result, the modal share of automobiles in the city stopped increasing for the first time ever in 2020.

Kanazawa is another city that ECOMO has recognized for proactive improvements to its walkability and transit sustainability.

“Kanazawa is a historical castle town ... (so) the roads in the urban area are narrow,” explains Sayaka Makino from Kanazawa’s urban policy bureau. “For this reason, we are advancing policies to create a walkable city where everyone from children to the elderly can live and get around in the castle town without relying on cars.” The city has made progress through developing a ring road circling the downtown, historical castle district; restrictions on private vehicles entering the castle town; new and improved bus lines; and a popular electric bicycle share program powered by 100% renewable energy.

“Our basic approach is urban development that gives priority to pedestrians, bicycles and public transit,” says Makino.

Meanwhile, Tokyo shows just how big the impact can be from declines in road vehicle emissions, with the latest accessible data from the capital showing that its transportation emissions dropped by over half from 2000 to 2019. This was mainly due to declines in emissions from road transportation, with improved road conditions leading to better fuel performance.

Piecing together successes from cities like Kanazawa and railway companies such as Tokyu, a path toward transit carbon neutrality starts to emerge: office commutes and travel undergone via renewable energy-powered trains; local lifestyles involving trips by foot, bike, light rail or bus in walkable cities. But these solutions have crucial limits.

A major one is that Japan’s rural regions, and in fact many of its cities, rely heavily on motor vehicles. While Tokyo has just 42.2 cars per 100 households, the figure nationwide is 103.7. Compared with other developed countries, Japan is in the middle-of-the-pack — fewer cars per capita than the U.S., Australia, Canada and Italy, but more than the U.K., Switzerland and Belgium.

As a result, 86.8% of emissions in Japan’s transportation sector — and 15.1% of the country's total emissions — come solely from cars and trucks.

But simply replacing every car in Japan with trains is a nonstarter. The automotive sector is crucial to the health of the economy — it was responsible for 12% of the nation’s gross domestic product in 2017. In addition, declining populations in rural areas make public transportation infrastructure difficult to maintain.

“You’ll still need cars in the countryside ... I don’t see a strategy for solving this contradiction,” adds Kumai.

If cars remain vital to transportation, carmakers will have to find a way to reduce emissions. In 2020, Japan set a national goal of electric vehicles representing 100% of new passenger car sales by 2035. Nevertheless, EV sales in Japan have notably lagged behind those in Europe and North America — they accounted for just 2% of new cars sold in the fiscal year ending in March, compared with 14% worldwide in 2022.

Looming behind all of these emissions is Japan’s persistent reliance on fossil fuels. Even electric cars aren’t green when running on electricity powered by natural gas and coal.

“If we don’t solve the problem of (sustainable) electricity generation, we can’t make progress,” says Kumai. “It’s the basis of our environmental crisis.”