By Barry Eitel

SAN FRANCISCO 

U.S. space agency NASA announced Friday the level of wintertime Arctic sea ice is one of the lowest in recorded history.

Researchers found sea ice levels for the winter season ending in 2018 were the second lowest since NASA began tracking the ice with satellites in 1979. The four lowest years for sea ice are, in order, 2015, 2016, 2018 and 2017.

Every winter, the ice covering the Arctic Ocean surrounding the North Pole thickens and freezes. During the spring and summer months, the ice thins and the extent of the ice retreats.

NASA said the amount of sea ice peaked this year on March 17 at approximately 14.5 million square kilometers (5.6 million square miles). This amount was 60,000 square kilometers (23,200 square miles) greater than the peak recorded in March of 2017, the lowest on record.

The 2018 maximum winter sea ice level was significantly lower than the average peak level recorded between 1981 and 2010 by 1.16 million square kilometers (448,000 square miles). NASA noted that this amount is equal to an area larger than the states of Texas and California combined.

“The Arctic sea ice cover continues to be in a decreasing trend and this is connected to the ongoing warming of the Arctic,” Claire Parkinson, a senior climate scientist with NASA, said in a statement.

“It's a two-way street: the warming means less ice is going to form and more ice is going to melt, but also, because there's less ice, less of the sun's incident solar radiation is reflected off, and this contributes to the warming.”

Scientists point to global warming as the major factor in the reduction of Arctic sea ice. The effects of the reduced sea ice near the North Pole has wide-ranging impacts, from affecting weather around the planet to shifting shipping lanes to altering the seasonal climate for the animals, plants and indigenous communities living near the Arctic Circle.