Greenland plays an outsized role in the daily weather experienced by billions of people and in the climate changes taking shape all over the planet.

Ice in the Arctic Ocean melted to its second lowest level on record this summer, triggered by global warming along with natural forces, U.S. scientists reported Monday. The extent of ice-covered ocean at the North Pole and extending further south to Alaska, Canada, Greenland and Russia reached its summertime low of 1.4 million square miles (3.7 million square kilometers) last week before starting to grow again. Arctic sea ice reaches its low point in September and its high in March after the winter. This year's melt is second only to 2012, when the ice shrank to 1.3 million square miles (3.4 million square kilometers), according to the National Snow and Ice Data Center, which has been keeping satellite records since 1979. In the 1980s, the ice cover was about 1 million square miles (2.7 million square kilometers) bigger than current summer levels.