When we think about global warming, our main concerns are often higher temperatures and rising sea levels, researchers say. But there’s another impending threat in the Arctic region: dangerously high amounts of rain replacing the snow.
In a three-year project funded by the National Science Foundation and led by researchers at the University of Massachusetts Amherst and Bates College in Maine, scientists will investigate a new pattern that’s unfolding in the Arctic.
Instead of receiving heavy snow all winter, the area is getting more rain, which leads to an increase in flash flooding, landslides, and avalanches, said Raymond Bradley, the study’s principal investigator and a climate science professor at UMass Amherst.
The Arctic region is warming the fastest, Bradley said, and researchers predict that these conditions are unique at least in the last 1,000 years, meaning it could be a result of global warming.
“This is one consequence of global warming that people haven’t thought about very much,” he said. “They always focus on temperatures and how warm it’s going to get, but the change from snow to rain is a really important factor not only in the Arctic, but around here, too. More freezing rain will have consequences for transportation and public safety in general.”
When more rain falls, the surface of the ground becomes saturated very quickly and because the underlying ground is often still frozen, a sludge of unstable materials forms that can lead to landslides, he said.
The precipitation changes are most threatening in the Norwegian archipelago of Svalbard.
“That town has experienced landslides and avalanches over the last few years,” Bradley said. “It’s killed people and wiped out houses in the town.
“This is kind of the leading edge that will happen in other communities in the Arctic, so we wanted to study how conditions are changing and how unusual this sort of thing is by looking at sediments in lakes near the town.”
Looking at sediment layers, researchers can find clues to weather and hydrological conditions from past years, Bradley said.
The scientists are looking for thick, grainy sediment layers, which indicate unusually large materials sliding down into lakes and rivers, and those point to signs that there has been heavier rain in the past, Bradley said.
If the team finds that these rainier conditions are not only unusual but also serve as evidence of larger global warming effects, Svalbard residents will have to rebuild their homes or redesign their community, Bradley said.
“It’s one of those ripple effects we get out of global warming that we tend not to think about,” he said. “And it’s looming.”Elise Takahama can be reached at firstname.lastname@example.org. Follow her on Twitter @elisetakahama.