Trees Don't Lie
If only somebody was listening ...
I wasn’t a huge fan of the talking trees in Peter Jackson’s Lord of the Rings movie trilogy. These ones have much more useful message.
I live at the centre of a fruit-growing area, and with an interest in climate change I’ve tried for years to obtain data from local orchardists to see if the seasonal cycles in their trees have shown any effects of climate change over the last 100 years or so. Sadly, the data appear to be lacking - and in any case may be suspect because of changing cultivars.
But climate-scientist guru James Hansen and his colleague Makiko Sato have come to the rescue. I was lucky enough to meet Hansen a few years ago during his lecture tour of New Zealand to talk about how to fix Climate Change. He’s been writing regular posts on the subject ever since, and they’re well worth reading. You can subscribe here for e-mail notifications.
His last posting included the very interesting plot below that shows the changing dates of the peak cherry-blossom bloom in Kyoto, Japan. Amazingly, unlike our region where the fruit trees have been present only over the last century and a half, these data go right back to the middle ages. It seems that the date of peak blooming may have been slightly earlier during the medieval warm period than throughout most of the period since, but those early data show a lot of year-to-year variability. Data from later in the period are much more complete, and show a smaller year-to-year variability.
The most striking feature is the accelerating advance in blossoming date since the beginning of the industrial revolution. The temperature rise from the ever-increasing rate of fossil-fuel burning since then is the most probable cause. The blossoms have bloomed earlier and earlier, and the peak blooming date is now at least two weeks earlier than it was before the change began about 150 years ago.
While some of that temperature change in Kyoto may be an urban heat-island effect, the map beneath that plot, beside the pretty picture of the blooming trees, shows large increases in springtime temperatures throughout the region over the last hundred years. The average global temperature in March increased by 1.2 C, but in Japan the increase was 3 C. The trees there are sending us a clear message. It’s a clear case of cause and effect.
As you can see from the map, temperature increases in New Zealand have been much smaller than in Japan, so any effects here would be harder to unravel. But I’d still love to have a try. Please let me know if there are any long-established fruit-growing families out there who’ve kept suitable historical records.
Thanks for reading this.😊 Previous posts on the intersection between Ozone, UV, Climate, and Health can be found at my UV & You area at Substack. Click below to subscribe for occasional free updates.