A recent study published in the journal Environmental Research Letters suggests that beavers’ actions could be contributing to climate change. The study, which involved analysis of high-resolution satellite imagery, has shown that beavers are constructing dams and lakes in the Alaskan tundra. The actions of these beavers are transforming the Alaskan landscape in a way that is dangerous to the environment. When they form new bodies of water, they contribute to the thawing of frozen permafrost, which is a natural reservoir for methane and carbon dioxide. When lakes are formed, these greenhouse gases are likely to leak into the atmosphere.
There has been a sharp increase in the number of beavers in the Alaskan tundra in the last two decades. According to the research, scientists have spotted increasing numbers of beavers over a very small area. These beavers carry dead trees and shrubs to create dams, resulting in new lakes that flood the permafrost soil and release methane.
The sudden rise in the number of beavers in the Arctic region has lead to more of these dams. Ingmar Nitze, a researcher from the Alfred Wegener Institute and author of the study, said, “We’re seeing exponential growth there. The number of these structures doubles roughly every four years.”
The study found that the number of dams in a 100-square-kilometer area around Kotzebue increased from two in 2002 to about 98 in 2019. This is a staggering 5000% increase in the number of dams. Nitze said that although the lakes can drain themselves and leave dry basins, the beavers are smart enough to block the outlets and refill the basins.
CNN reported that the Arctic permafrost is melting at an alarming rate. These natural methane and carbon dioxide reservoirs are releasing large amounts of greenhouse gases into the atmosphere. Several studies are now underway to determine the amount of carbon dioxide being released from such reservoirs. “There are a lot of people trying to quantify methane and CO2 emissions from lakes in the Arctic but not specifically yet from beaver lakes,” Nitze explained.
The researchers now fear that similar beaver actions may be happening in other areas as well. Nitze warned that the same could be happening in the Canadian tundra and Siberia among other places in the world.
Image via Jan Erik Engan