NOAA publishes its annual report tracking recent Arctic environmental changes.
What’s new in 2012?
New records set for snow extent, sea ice extent and ice sheet surface melting , despite air temperatures - a key cause of melting - being unremarkable relative to the last decade.
Multiple observations provide strong evidence of widespread, sustained change driving Arctic environmental system into new state.
Record low snow extent and low sea ice extent occurred in June and September, respectively.
Growing season length is increasing along with tundra greenness and above-ground biomass. Below the tundra, record high permafrost temperatures occurred in northernmost Alaska.
Severe weather events included extreme cold and snowfall in Eurasia, and two major storms with deep central pressure and strong winds offshore of western and northern Alaska.
The full report in PDF format is available here.