It seems like whenever the word “cold” pops up in the news, climate skeptics point to it as evidence that global warming is all a sham. It happened during 2013’s polar vortex, and then again this past November. It happened during last month’s “snowmageddon” under Winter Storm Juno, but as our editor-in-chief, Pierce Nahigyan, pointed out, the freakish cold and buckets of snow that pummeled the east coast a few weeks ago are actually symptoms of global warming. Warmer waters are providing more energy for storms to draw from, and these storms are now being accompanied by floods and surges – something that does not happen in normal winter circumstances.
So when you hear that Antarctica enjoyed record-high levels of sea ice last year, remember that it’s part of a larger story.
The truth is, scientists aren’t entirely sure why Antarctica has been gaining all this sea ice. Underwater drones may help in this regard, and have already determined that warm salt water is rising up and eroding the continent’s western coast. This could partly explain why, despite Antarctica’s growing sea ice, the melt rate on its western side has increased threefold in the last ten years. In the last three years, three glaciers in the area have lost so much ice that the Earth’s gravitational field was minutely affected.
What scientists do know, however (and beyond any shadow of a doubt), is that the loss of sea ice in the Arctic dwarfs any gains made at the South Pole. A recent study published in the journal American Meteorological Society and headed up by Claire Parkinson, a sea ice researcher at NASA’s Goddard Space Flight Center, shows that global levels of sea ice have consistently decreased over the last four decades.
Researchers combined satellite records of the north and south poles and found that all twelve months of the year showed negative trends for sea ice extent over the 35-year period between 1979 and 2013.
“The paper conveys an important message that is often lost when climate change skeptics point to the increasing trend of sea ice in the Southern Hemisphere: The Arctic has lost much more sea ice than the Antarctic has gained,” John Walsh, editor of the AMS and a climate scientist at International Arctic Research Center at the University of Alaska Fairbanks, wrote in an email to Climate Central. “In other words, the planet as a whole is losing sea ice.”
In fact, sea ice loss for the planet is equivalent to about 13,500 square miles per year from 1979 to 2013. The melt rate also doubled from 1996 onward.
The impact of global warming on the Arctic is also a self-perpetuating one. Melting ice forms ponds or pools of ocean water, which absorb the sun’s rays. This counteracts the albedo of snow and ice (the ability to reflect solar radiation back into space) and leads to further melting.
“I hope that these results will make it clear that, globally, the Earth has lost sea ice over the past several decades, despite the Antarctic gains,” Parkinson told Climate Central.
The loss in sea ice does not directly affect rising sea levels, but it has already affected weather and wildlife. It has increased the risk of harsh winters in Europe and Asia and led to massive waves in the Arctic circle. Less ice also means that animals that use it to hunt or travel can become stranded or even starve in areas that were once icy, unbroken expanses. This has contributed to major declines in polar bear populations and forced thousands of walruses onto Alaskan beaches.