This winter, to stay warm and use less energy, the governor of Tokyo has advised people to wear turtlenecks.

Yuriko Koike said wearing turtlenecks could help reduce energy bills.“Warming the neck has a thermal effect. I’m wearing a turtleneck myself and wearing a scarf also keeps you warm. This will save electricity,” Yuriko Koike told reporters on Friday.

“This is one of the tools to get through the harsh winter energy climate together.” She said the French president, Emmanuel Macron, was “taking a lead in wearing turtlenecks."

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A casual dress code is encouraged in offices as part of Japan's long-running "cool biz" campaign, which aims to conserve energy during the country's sweltering summers. The winter version is labeled, appropriately enough, “warm biz”.

Japan, which wants to achieve carbon neutrality by 2050, has experienced a tightening of the energy market since the war in Ukraine. 

In an effort to address the skyrocketing costs of imported energy, the Japanese Prime Minister, Fumio Kishida, called for a push to revive the nation's nuclear power industry in August.

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However, after the Fukushima nuclear disaster in 2011, which was brought on by a large tsunami and forced the suspension of many reactors out of concern for safety, such a move would likely be met with opposition.

Ten of Japan's 33 nuclear reactors are back in operation eleven years later, though not all of them are, and the nation is still largely dependent on imported fossil fuels.