Colorado researchers have found that ice on the Arctic Ocean has melted to its second-lowest level on record. This increased Arctic ice melt is already affecting wildlife in the ocean, and coincides with a dramatic warming over the past 10 years.
Arctic ice comes and goes throughout the seasons, with about half melting away by mid-September and a regrowth after it reaches that low point. In 2007, there was a record low level of ice left. According to Mark Serreze, head of the National Snow and Ice Data Center in Colorado. The remaining ice in the Arctic this season is reaching a similarly low level.
“What it’s telling us is that the long-term decline in Arctic sea ice is continuing, and even appears to be accelerating at this point,” he says.
He says the 2007 low was due in part to near-perfect weather, which pumped large amounts of warm air into the Arctic. Changing wind patterns and strangely cloud-free skies contributed to the melting. This year the ice melt is nearly as much, without any extreme weather playing a role.
This sets up a vicious cycle, as there is no question the Arctic Ocean will freeze again this winter, but with less and less of a build-up of thick ice as time goes by.
According to Serreze, the Arctic could be ice-free by the summer of 2030. However, this difficult prediction is different from some other scientists, who say it could be mid-century before that momentous point is reached.
Why should we care about ice on the arctic, anyway? While the ice melting doesn’t raise the sea level and pose a risk for nearby land, it’s already beginning to affect Arctic wildlife.
When the only ice left off the coast of Alaska is over extremely deep water, walruses that typically float around on ice and dive down to feed on the ocean floor, abandon it due to the longer time it takes to swim to the bottom. Many now go to the northwest Alaskan shore and feed from there. It is more hazardous for walruses to sit on rocks instead of ice. In the event of a disturbance, walruses will quickly flee to the water and run over calves, leaving them for dead.
It is uncertain how walruses will continue to thrive if Arctic ice melts away completely during the summer. Scientists are also researching how it will begin to affect other Arctic wildlife.
Image by NASA Goddard Space Flight Center: Arctic Sea Ice Maximum and Minimum 2011