Sea ice in the Arctic Ocean and off the Antarctic coast has shrunk from the 1981-2010 average to a record low after losing 3.84 million-square-kilometers of ice cover, equivalent to an area the size of India.
Climate scientists have attributed the decline in ice cover to human-caused greenhouse emissions and the El Niño weather event.
Despite global warming and a steady retreat of ice at Earth's northern tip, ice on the Southern Ocean off Antarctica has tended to expand in recent years. But now, scientists have found that it is shrinking at both ends of the planet, Reuters reported.
This year is the warmest on record. Scientists have recorded a temperature of 20 degrees Celsius above normal in some days of November. "There are some really crazy things going on," said Mark Serreze, director of the U.S. National Snow and Ice Data Center (NSIDC) in Boulder, Colorado.
Antarctica's expanding sea ice has been used in the argument that global warming might not be man-made after all. But the recent discovery has shifted the course of thinking. A recovery of the high-altitude ozone layer over Antarctica, which led to cooler air over the continent when it was damaged by now-banned industrial chemicals, may also be a factor.
However, John Turner of the British Antarctic Survey said that it is hard to pinpoint exactly what was happening. "When we began getting satellite data from 1979 the sea ice started to decrease. Everyone said it was global warming ... but then it started to increase again," he said.
Last year, almost 200 governments agreed to phase out fossil fuels this century and limit the global temperature rise above pre-industrial levels to less than two degrees celsius. This year, U.S. President-elect Donald Trump has threatened to pull out of that agreement calling global warming a hoax.
The polar regions are radically different from each other because the Arctic is an ocean ringed by land and Antarctica is a vast land mass surrounded by water. According to scientists, Antarctica's glaciers could slip more quickly into the ocean, if there is less ice floating on the sea to pin them back, speeding up the pace of the sea level rising.