After 1,200 years, cherry blossom record to live on despite Japanese scientist’s death

Hi r/environment, this is Emma from The Guardian. We wanted to share this story on a campaign to continue the 1,200-year cherry blossom record in Japan, which charted shifting bloom dates as a marker of climate change. 

*From our story:*

Even in his final months, he counted the days until the cherry blossoms. Prof Yasuyuki Aono of Osaka Metropolitan University spent his career gathering data on the spring flowering dates of cherry trees in Japan in what is one of the world’s longest climate records tracking a seasonal occurrence.

Using sources dating as far back as the 9th century, he revealed that cherry tree flowerings have occurred progressively earlier in recent decades – a now famous marker of climate change.

Last April, Aono posted a photo to social media of his spreadsheet. He had just completed the 2025 entry, recording “4 [April]” as the peak flowering date for the particular cherry tree species he tracked, the mountain cherry, or Prunus jamasakura.

Below this, the next row was already marked “2026” but Aono never got to fill it in. He died on 5 August last year, according to former colleagues contacted by the Guardian.

“You can very much see that he planned to continue,” said Tuna Acisu, a data scientist at Our World in Data, an online platform that publishes a chart based on Aono’s cherry tree data. “That made me a little bit emotional.”

Now, following a search launched by Acisu last week – sparked by fears that no one would be able to continue the 1,200-year cherry blossom record – a researcher in Japan has stepped forward and offered to make formal observations of the mountain cherry’s spring flowerings.

[You can read the full story for free at this link.](https://www.theguardian.com/world/2026/apr/15/cherry-blossom-1200-years-japan-climate-scientist-yasuyuki-aono?referring_host=Reddit&utm_campaign=guardianacct)