Both land and sea ice cover in the Arctic have decreased since the late 1970s and the trend is expected to increase in the future due to a changing climate. The March 2018 Arctic sea ice annual maximum joined 2015, 2016, and 2017 as the four lowest maximum extents on record (2018 is fourth lowest) and the September 2018 Arctic sea ice annual minimum is likely to be the sixth lowest in the satellite record. The seven smallest Arctic sea ice minimums have occurred in the last seven years and the 14 smallest Arctic sea ice maximums have occurred in the last 14 years.
Arctic sea ice is frozen seawater that floats above the Arctic Ocean – it plays an important role in regulating the planet’s temperature. Snow and ice reflect solar energy back into space, whereas dark ocean waters absorb it. As more ice melts due to warmer air temperatures, the oceans are able to absorb more energy and heat. In turn, the warmer oceans increase ice melt and air temperatures in the Arctic, and influence atmospheric circulation and precipitation patterns in the Arctic and beyond.
The decrease in sea ice also affects many Arctic marine mammals, including whales, seals, walruses and polar bears that rely on the ice to live, feed and breed. Many species of seals use the sea ice to give birth and nurse their young during the spring, and polar bears use sea ice for feeding in late to early winter.
Republished from NEEF: https://www.neefusa.org/nature/water/diminishing-arctic-sea-ice