Nearly all of the major news outlets last week ran attention-grabbing headlines uncritically reporting a supposed crisis of rapidly increasing melting of Antarctica. According to the reporting, accelerated melting of the continent’s ice could raise sea level significantly and bring catastrophic coastal flooding to communities all over the world. If true, we should all be very alarmed about severe negative consequences to hundreds of millions of people.
This spate of Antarctic alarm was triggered by a study from an international team that measured ice volume and reported a dramatic increase in ice loss in recent years. This new study contradicts previous research which had consistently shown the continent steadily gaining ice volume since the beginning of the satellite era in the late 1970s.
NASA glaciologist Jay Zwally — likely the pre-eminent expert on Antarctic ice accumulation and loss — published a study in 2015 showing that ice loss in western Antarctica* and the Antarctic Peninsula was more than offset by significant accumulations in the rest of the continent. Both Zwally and the recent researchers were measuring the same thing, but the difference appears to be in the corrections made in adjusting for the movement of the Earth beneath the ice.
As ice accumulates or diminishes, the Earth beneath is either flexed downward or upward due to the changing weight of the overlying ice. In some cases, this “basement” rock is covered by more than 15,000 feet of ice, so an exact science this is not. Zwally is reportedly preparing a new report that will soon bolster his findings of a net ice gain.
“The good news is that Antarctica is not currently contributing to sea level rise, but is taking 0.23 millimeters per year away,” says Zwally.
So, the bottom line in this roiling debate is we have two camps of climate scientists arguing over extremely small adjustment made to sensitive data. Not one person reading this will have any idea which side is actually correct. Zwally may well be correct, but none of us has the specialist’s knowledge to judge the merits of this intensely technical discussion.
Luckily, we have another test of Antarctic ice growth that is not dependent on a researcher’s intended or unintended biases.
The extent of Antarctica’s sea ice is quantifiable and easily measured by satellites. There is overwhelming agreement that this ice has been steadily increasing for the last several decades. In fact, the very study that recently reported ice volume losses admits as much in its introduction by stating, “…maximum extent of the sea ice has increased modestly since the 1970s…”
The evidence of increasing Antarctic ice is clear, stark and overwhelming. The National Snow and Ice Data Center (NSIDC) manages data for NASA and NOAA and reports an increase of 1.8% of sea ice extent per decade. The most recent monthly data (May 2018) from NSIDC showed that during the early Antarctic winter, sea ice increased by 47,000 square miles per day, “somewhat faster than the 1981 to 2010 average growth rate.”
Rest easy, Antarctica isn’t melting away, and you aren’t going to drown because of it.
*Footnote: Unreported in all the hub-bub over this melting or not-melting is the fact that the melting ice of western Antarctica sits atop what has been described as a natural blowtorch of intense geo-thermal heat. Beneath the ice is an area that hosts possibly the densest region of volcanoes in the world. Many researchers have attributed a goodly portion of the ice loss in this area to these naturally driven heat sources, not to man-made warming.
Gregory Wrightstone, author of “Inconvenient Facts: The Science That Al Gore Doesn’t Want You To Know,” is a geologist with more than 35 years of experience researching and studying various aspects of the Earth’s processes. He is a member of the American Association for the Advancement of Science and the Geological Society of America.