Can’t wait any longer for spring? If you live in a northern region of the planet, you might see it coming a few days early. And according to a US study, this phenomenon could continue for decades.
We already knew that higher temperatures due to climate change are accelerating the arrival of spring in certain parts of the world. But this new study, published in Nature Climate Changeshows that the decrease in the number of rainy days also plays an important role.
According to calculations made during the study, the decrease in the frequency of precipitation in late winter and early spring could cause trees to bloom one to two days earlier than previous scientific estimates every decade, until 2100.
This phenomenon is explained by the greater solar radiation that stimulates leaf growth. The lack of rain also implies higher temperatures during the day, but cooler at night in the absence of clouds, which have the role of retaining heat. In other words, plants and trees receive sufficient light and moisture for optimal growth.
“This contrasting effect makes plants think it’s spring, so leaf growth starts earlier and earlier”explains Jian Wang, co-author of the study and PhD student in geography at the State University of Ohio (United States).
An earlier spring in the Northern Hemisphere
To arrive at these conclusions, the authors of the work collected a series of data from the United States, Europe and China. The researchers collected data for the first appearance of leaves and analyzed satellite images from 1982 to 2018 to determine the time of year when vegetation began to turn green. Finally, this information was compared with the number of monthly rainy days for each of the surveyed areas.
The results showed that with the decrease in the number of rainy days over the years, spring will come earlier and earlier for most parts of the planet in the Northern Hemisphere. The only exception is grasslands that are (mostly) in semi-arid areas, where the decrease in the number of rainy days can actually delay the onset of spring somewhat.
Other climatic phenomena related to human activities may contribute to hasten the arrival of spring. This is especially true for light pollution, according to another US study published in November 2021 in the journal Science†
(ETX Daily Up)