The National Oceanic and Atmospheric Administration (NOAA) tracks changes in the environment and has released the Arctic Report Card: Update for 2012. Based on multiple observations, the report finds “strong evidence of widespread, sustained change driving Arctic environmental system into new state,” and highlights the following:
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. Duration of melting was the longest observed yet on the Greenland ice sheet, and a rare, nearly ice sheet-wide melt event occurred in July.
Massive phytoplankton blooms below summer sea ice suggest previous estimates of ocean primary productivity might be ten times too low. Arctic fox is close to extinction in Fennoscandia and vulnerable to further changes in the lemming cycle and the encroaching Red fox.
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.
This year also marks the first time that there has been less than 4 million square kilometers (1.54 million square miles) of sea ice since satellite observations began in 1979. Visualization here.