In parts of Alaska, beaver activity is hastening the regional thawing of the permafrost, releasing long-trapped greenhouse gases into the atmosphere. Credit: Steve Hillebrand/U.S. Fish and Wildlife Service Alaskan beavers are carving out a growing web of channels, dams and ponds in the frozen Arctic tundra of northwestern Alaska, helping to turn it into a soggy sponge that intensifies global warming. On the Baldwin Peninsula, near Kotzebue, for example, the big rodents have been so busy that they’re hastening the regional thawing of the permafrost, raising new concerns about how fast those organic frozen soils will melt and release long-trapped greenhouse gases into the atmosphere, said scientists who are studying the beavers’ activity. The number of new beaver dams and lakes continues to grow exponentially, suggesting that “beavers are a greater influence than climate on surface water extent,” said University of Alaska, Fairbanks scientist Ken Tape , a co-author […]