Antarctica’s ice sheet is significantly retreating

By CINDY JIANG | April 19, 2018

Global warming has been a key term in conversations about the environment throughout the past few decades. 

It is the term attributed to the annual increase in rising temperatures on Earth, influenced by factors such as the burning of fossil fuels and other human activities. These endeavors contribute a considerable amount of greenhouse, or heat-trapping gases, to the atmosphere and consequently raise the surface temperature. 

New findings from a study conducted by the University of Leeds in Britain and the University College London showed that Antarctica’s ocean-front glaciers are retreating. 

This discovery is concerning, especially when considering the fact that the continent has enough ice to raise sea levels by about 200 feet. 

Approximately 80 percent of the heat produced by the presence of greenhouse gases is absorbed by the oceans, which in turn leads to several factors that increase sea levels — thermal expansion, melting glaciers and polar ice caps, and ice loss from Greenland and West Antarctica.

Thermal expansion takes place when water molecules expand from the addition of heat and therefore occupy more space. Melting glaciers and polar ice caps are part of the problem as well, since higher temperatures lead to an imbalance in summer melting and winter snowfall patterns. Greenland and West Antarctica undergo a similar fate as ice sheets melt at an accelerated rate.  

As sea levels continue to rise rapidly, the effects that these changes in water level have on land, particularly coastal habitats, is disastrous. 

Erosion, wetland flooding, aquifer and agricultural soil contamination, and habitat destruction for fish, birds and plants are just some of the possibilities.

The majority of the glaciers that make up Antarctica lie on the sea floor at the grounding line, where the ice meets ocean and bedrock. The introduction of warm ocean water makes the grounding line retreat, so in 10.7 percent of glaciers, the continental ice masses are retreating, compared to the 1.9 percent of growing glaciers. 

The recession of grounding lines exposes increasing amounts of ice to the ocean water, prompting a change in sea level. 

“We find that 10 percent of the Antarctic ice sheet [is] significantly retreating, but we can’t somehow extrapolate sea level rates that come from that. But to say 10 percent of Antarctica, this massive ice body, is retreating, still should be some sign of warning. It’s large,” Hannes Konrad, lead author of the study, said, according to the Washington Post.

The Thwaites glacier of West Antarctica is in the worst condition, with a retreating rate of up to 300 to 400 meters per year along a central section. 

“Imagine other coastlines changing at an equal speed, that’s really massive,” Konrad said.

Comments powered by Disqus

Please note All comments are eligible for publication in The News-Letter.