Retreat of the snow monsters

Back in the 1980s, Project Hyakumeizan was astonished at the snow monsters on Hakusan. More soberly known as “juhyō” (tree ice), these are the fantastic figures wrought by the trees encrusted with the snow and hoar-frost swept in by the blizzards from the Japan Sea. You can still see them up there, but perhaps not for much longer.

Ice monsters on Hakusan, Advent Sunday 1981

The problem is the climate. Ice monsters will all but vanish from Japan by the end of the century unless climate change slows, warns Fumitaka Yanagisawa, a professor emeritus at Yamagata University’s Research Institute for Ice Monsters and Volcanoes of Zao, as reported in the Asahi Shimbun.

Using historical records, Professor Yanagisawa has established that juhyō previously flourished in a wide arc stretching from Hokkaidō in the north to Ishikawa’s Hakusan massif in the south. But this range has has been shrinking, both from southern end and, less obviously, from the north – where, in Hokkaidō, the mountains are no longer high enough to support the special conditions in which juhyō thrive, namely temperatures of minus 10–15 degrees, two to three metres of snow, and strong northwesterly or westerly winds with a speed of 36 to 54 kph, among others.

Yōteizan, Hakkōda, Zaō, Hachimantai, Azumaya, Hakusan, even humble Makihata – many of the mountains named by Professor Yanigasawa as current and former juhyō habitats also belong to the One Hundred Mountains of Japan. Indeed, the snow monsters put in an occasional appearance in Japan’s most famous mountain book:

I first visited Zaō when word of its frozen trees was first reaching the outside world. At that time, the only shelter above Takayu hot springs was the Kobold Hut belonging to the former Yamagata High School. After that visit, I went to the massif to ski every winter. After the war, however, I have not returned, fearing the crowds that must now overwhelm it …

It would be a pity if the juhyō were to join the Kobold Hut* and a pristine Zaō as half-forgotten footnotes in the history of Japan’s mountains …

References

Sakata, Tatsuro, Climate change quietly slaying Japan’s ‘juhyo’ ice monsters, Asahi Shimbun, 12 March 2023

Alan Taylor, Juhyo: The Snow Monsters on Japan’s Mount Zao, The Atlantic, 22 January 2020

*It seems that the Kobold Hut has survived to this day, now owned by Yamagata University: see this blog post.