Cherry Blossoms and Global Warming

April 4, 2021

April in Japan is a kind of special month.

New lives start in many places. Students enter new schools or start new grades. Many of graduated students begin to work. Workers welcome young colleagues.

Japanese system may be a bit unique but school term starts in April, so as true for fiscal year of many of companies. Entrance ceremonies from kindergartens, elementary schools, high schools to colleges & universities, even companies are taken place in the beginning of April.

Full bloom of cherry blossoms used to be a symbol of such entrance ceremonies. Many of schools plant cherry trees in their grounds, and it used to be a popular “ceremony” for fresh students to take pictures with their classmates, teachers and parents with blooming cherry blossoms in their back.

Recent years, however, cherry blossoms in April are too late to enjoy in and around Tokyo. They bloom in the latter half of March. This year, 2021, full bloom was announced on March 22.

Believe or not, the announcement is made by a governmental entity, Japan Meteorological Agency. They pick a standard cherry tree in each area, and visually observe the tree to judge if blossoms start to bloom, 30% bloom, full bloom and so on. What a peaceful job!!

Mid of March, by the way, is a graduation season. Graduate students should have enjoyed cherry blossoms after the ceremonies this year, while group photos may not be taken because of Covid infections.

You can imagine cherry blossoms are now symbols of graduate ceremonies instead of entrance ceremonies.
Full blooming gets two to three weeks earlier in, say, 30 years. Many people believes the reason is so called global warming. This is the reason, of course, Japan Meteorological Agency observe cherry blossoms every year.

I would like to propose alternative hypothesis here.
Older the cherry trees get, earlier they “wake up”, which is true for human beings…