Autumn air temperatures have climbed to record levels in the Arctic due to major losses of sea ice as the region suffers more effects from a warming trend dating back decades, according to a new report.
The annual report issued by researchers at the US National Oceanic and Atmospheric Administration and other experts is the latest to paint a dire picture of the impact of climate change in the Arctic.
It found that autumn air temperatures are at a record 5 °C above normal in the Arctic because of the major loss of sea ice in recent years, which allows more solar heating of the ocean.
That warming of the air and ocean impacts land and marine life and cuts the amount of winter sea ice that lasts into the following summer, says the report.
The report adds that surface ice is melting in Greenland and that wild reindeer, or caribou, herds appear to be declining in numbers.
“Changes in the Arctic show a domino effect from multiple causes more clearly than in other regions,” says James Overland, an oceanographer at NOAA’s Pacific Marine Environmental Laboratory in Seattle and one of the authors of the report.
“It’s a sensitive system and often reflects changes in relatively fast and dramatic ways,” he says.
Researchers at the National Snow and Ice Data Center, part of the University of Colorado, recently reported that, this summer, Arctic sea ice melted to its second-lowest level ever.
The 2008 season, those researchers said, strongly reinforces a 30-year downward trend in Arctic ice extent – 34% below the long-term average from 1979 to 2000, but 9% above the record low set in 2007.
Last year was the warmest on record in the Arctic, continuing a region-wide warming trend dating to the mid-1960s. Most experts blame climate change on human activities spewing greenhouse gases into the atmosphere.