Advertisement

36 years of bike race footage reveals how Belgium's climate is changing

Trees along the race course are “leafing out’ earlier every year

Belgian cyclist Tom Boonen, of the Quick Step team, left, follows Belgian cyclist Leif Hoste, of the Discovery Channel team, as they climb the Wall of Grammont during the Tour of Flanders cycling classic in Grammont, Belgium, Sunday April 2, 2006
AP Photo/Bas Czerwinski

Green-thumbed grandmothers the world over have noticed a disturbing trend: Spring seems to be arriving earlier every year. But without hard data, it's difficult to back up those claims. Now, scientists have found a new source of data—old television footage of outdoor sporting events, which reveals how early trees and other plants are "leafing out" each year.

Scientists started with footage of the Tour de Flanders (above), a professional cycling race that's taken place in Belgium nearly every April since 1913. The researchers watched more than 200 hours of video for races from 1981 to 2016, picking out 20 trees that they could see clearly in subsequent years. For each tree, they noted the presence—or absence—of leaves, along with their size.

The old footage reveals that spring has sprung earlier along the race course in the past decade. In the 1980s, hardly any trees had leaves during the race. But from 2006 to 2016, 45% of trees had at least started growing leaves, the team reports today in Methods in Ecology and Evolution.

It isn't surprising that the Belgian trees are leafing out earlier, given previous studies in places with detailed leaf-growth records. But this is the first time researchers have used old sporting footage to come to similar results. The team says this latest study is just a start, and old television footage could be a valuable resource in the quest to understand how climate change is affecting plants.

*Correction, 5 July, 9:45 a.m.: This story has been updated to correct the percentage of trees that started growing leaves from 2006 to 2016.


Support nonprofit science journalism

Help News from Science publish trustworthy, high-impact stories about research and the people who shape it. Please make a tax-deductible gift today.

Donate

Not Now

Thank you for reading News fromScience.

You have reached your limit of 3 free news stories in the past 30 days.

To gain unlimited access to News fromScience, pleaseLog inor subscribe to News from Science.

AAAS Members canLog infor unlimited access.

$2.99/Month$25/YearFrequently Asked Questions