Only a few herds of reindeer and caribou are increasing or are stable at high numbers; most herds continue to decline or remain at low numbers after severe declines in recent decades. Whether these trends are a result of Arctic climate change or part of a natural pattern is still unknown.
Since observations began in 1982, Arctic-wide tundra vegetation productivity has increased. In North America, the rate of greening has accelerated since 2005.
Since the early 1990s, annual atmospheric equivalent black carbon concentrations in the Arctic have decreased at the surface by as much as 55 percent—one of the few "good news" stories coming out of the region.
After record-breaking melt during the 2012 season, the 2013 melt extent was more on par with the long-term average. The reprieve from the record warmth and melting of the past six summers is likely connected to a strong positive phase of the North Atlantic Oscillation during summer 2013.
Most of the Arctic boundary waters were warmer than average in summer 2013, but a few cool pockets appeared in the western Arctic and the Greenland Sea. Warmer waters are drawing new species from lower latitudes into the Arctic.
In March 1988, thick, multi-year ice comprised 26 percent of the Arctic's ice pack. In 2005, that number dropped to 19 percent. In 2013, it dropped to 7 percent.
Averaged over September 2013, sea ice extent was 2.07 million square miles—larger than last year's record low, but still more than 17 percent below average and the sixth smallest September extent on record.