By watching an annual bicycle race researchers found evidence of climate change. The Liège–Bastogne–Liège one day race has been running for decades and filmed since at least the 1980s. Because the route covers much of the same ground every year some researchers figured that they could use it to witness how plants are reacting to our warming climate, so they watched a lot of races but watched the trees not the racers. This sort of research is really neat since it provides another way to visually analyze our planet and share that knowledge.
Co-author Lisa Van Langenhove sifted through more than 200 hours of television data of the race shot between 1981 and 2016. Though the route had changed over the years, the team selected 12 climbs and landmarks where they could pinpoint individual trees. They studied 46 trees in particular. Most of them were not native to the area and included magnolia, hawthorn and forsythia.
The researchers found that in the 1980s, there were virtually no leaves on trees. After 1990, however, many trees were already in full leaf.
The change was significant. When leaves begin to emerge on a tree branch, it’s referred to as flushing. The study found that between 2006 and 2016, 45 per cent of trees had begun to grow leaves. That’s compared to nearly zero in the 1980s.