More recently, scientists have focused on collapsing ice sheets in western Antarctica. In May, NASA scientists told reporters that west Antarctic glaciers had gone into “irreversible retreat” which could raise sea levels between 10 and 13 feet.
“Today we present observational evidence that the [ice sheet] has gone into irreversible retreat,” said Eric Rignot
, the lead author of a study claiming the western Antarctic was collapsing. “It has reached the point of no return.”
Researchers at the University of Washington corroborated Rignot’s findings by using computer
models to determine the western Antarctic ice sheet was collapsing — though the collapse would occur over centuries, between 200 to 900 years.
“Our simulations provide strong evidence that the process of marine ice-sheet destabilization is already under way on Thwaites Glacier, largely in response to high subshelf melt rates,” wrote the University of Washington scientists in their study published in the journal Science
. “Similar behavior also may be under way on neighboring Pine Island Glacier.”
But past studies have shown
the Antarctic glacier collapses are nothing new. The British Antarctic Survey (BAS) put out two studies in the past year showing that Antarctica has gone through similar periods of glacier collapse in the past.
A BAS study
from February 2014 shows that 8,000 years ago Antarctica’s Pine Island glacier thinned just as quickly as it has in recent decades — thousands of years before massive amounts of man-made carbon dioxide emissions were released into the atmosphere.
Not only did the Pine Island glacier melt rapidly in the past, it was also able to naturally reverse the melting.
Another BAS study from last year argued the current melt in the western Antarctic is within the “natural range of climate variability” of the last 300 years.
“The record shows that this region has warmed since the late 1950s, at a similar magnitude to that observed in the Antarctic Peninsula and central West Antarctica,” said a BAS study published
in the journal Geophysical Research Letters, “however, this warming trend is not unique.”
“More dramatic isotopic warming (and cooling) trends occurred in the mid-19th and 18th centuries, suggesting that at present the effect of anthropogenic climate drivers at this location has not exceeded the natural range of climate variability in the context of the past ~300 years,” the study continued.