At the close of 2014, experts report that the influence of long-term upward trends in air temperatures continues to be felt throughout the Arctic environment.

In late winter 2014, a shifting of the polar vortex allowed cold Arctic air

to spill southward into the United States,

and temperatures in Alaska and Russia were far warmer than usual.

Summer sea ice in 2014 was below long term amounts

but was not as low as the extreme loss years of 2007 and 2012.

Less sea ice exposes previously ice-covered water to warmth from the sun,

increasing upper ocean temperatures in all the marginal seas of the Arctic Ocean.

Increased sunlight into the ocean increases photosynthesis

and when sufficient nutrients are available,

increases primary production.

The shorter ice season, with earlier sea ice break-up and later freeze-up,

is having adverse effects on polar bear conditions.

Reproduction rates and numbers are lower in Hudson Bay.

In the Chukchi Sea, polar bears have been stable for 20 years,

but polar bear condition, numbers, and reproductive rates have declined in the adjacent southern Beaufort Sea.

On Arctic lands, the ecosystem is changing, as small tundra plants are being replaced by shrubs and trees.

However, there has also been an unexplained browning and a shorter growing season over large areas,

especially in Eurasia.

There was a new record low set for April snow cover extent in Eurasia,

and the June extent in North America was the third lowest in the record.

The Greenland ice sheet experienced extensive melting again in 2014.

As in previous years, multiple changes continue to occur throughout the Arctic environment.