According to a recent study by Australian and British researchers, as initially reported by Reuters, the rate at which ice is melting in Antarctica during the summer is at the highest level in 1,000 years.
The researchers—from the Australian National University and the British Antarctic Survey—found from data taken at the ice core that summer ice melt has been ten times more intense over the past 50 years than they were 600 years.
Lead researcher Nerilie Abram and her team drilled to the ice core on James Ross Island, roughly 400 yards deep, to measure the historical temperatures so that they could compare them with the current summer ice melt levels.
Their findings, published in the Nature Geoscience journal, were simple: Temperatures have increased by 1.6 degrees Celsius over 600 years, but the rate of ice melting has been the most intense over the past 50 years.
“It’s definitely evidence that the climate and the environment is changing in this part of Antarctica,” said Abram. “Once your climate is at that level where it is starting to go above zero degrees, the amount of melt that will happen is very sensitive to any further increase in temperature you may have.”
According to Robert Mulvaney, of the British Antarctica Survey, the stronger ice melts are most likely responsible for the glacier loss and ice shelf collapses seen during the past 50 years. In fact, according to a recent study by a Texas A&M University researcher, the melting rates of glaciers in Antarctica are accelerating due to global warming.
Alejandro Orsi, associate professor of oceanography, and his colleagues from the University of Gothenburg in Sweden, “examined the entry to one of three cross-shelf passages in the Amundsen Sea that allow warm oceanic water to reach beneath the ice shelves in front of the Thwaites and Pine Island Glaciers, which show the fastest thinning.” Their findings were far from ideal: They found a year-long persistent inflow of warm bottom water along this trough.
“The first reaction was to look for direct atmospheric anomalies in Antarctica, since air temperature would be easiest to be blamed, but we found that is not necessarily the case here,” Orsi explains in a press release. “These changes are being driven mainly by the ocean, which in turn interacts with the atmosphere in complex ways.”
The scientists at the University of Innsbruck disclose that between 1902 and 2007, the total sea level rise was 20 centimeters (about 8 inches) and of that, glaciers melting contributed 11 centimeters (4.33 inches). They estimate that by the year 2100, melting glaciers could potentially raise sea levels by an additional 22 centimeters.
The Associated Press reports:
Sea water that expands as it warms, melting ice sheets and changing water storage in dammed lakes and underwater reservoirs are also said to have contributed to rising sea levels.
The scientists say glacier melts were tracked by numerically modeling each of the world’s roughly 300,000 glaciers and then performing thousands of on-site measurements to validate the model results.
Unfortunately, melting glaciers are becoming a devastating norm: Due to global warming, many of the world’s glaciers are rapidly melting at unprecedented rates and are breaking off unnaturally. Another study, led by climate scientist Jonny Day at the National Centre for Atmospheric Science at the University of Reading, the loss of arctic sea ice is, at the very least, 70 percent man-made. And that’s just the low ball estimate–the study shares that climate change could be up to 95 percent due to human-induced climate change!
Photo by Liam Quinn