Researchers have determined that the largest glaciers in West Antarctica are collapsing and there is no way to stop it. It is feared that this is the beginning of a domino effect that can cause the entire ice sheet to melt, even if drastic measures to reduce greenhouse gases are taken.
Lead study author Eric Rignot, a glaciologist at the University of California, Irvine and NASA’s Jet Propulsion Laboratory in Pasadena, California said, “These glaciers will keep retreating for decades and even centuries to come and we can’t stop it. A large sector of the Antarctic Ice Sheet has passed the point of no return. It is quite likely the retreat of these glaciers will accelerate in the future rather than slow down.”
An ice sheet is often miles thick and is part of a continent sized ice cap. Ice sheets are drained by flowing glaciers, much the way a lake is drained by streams.
10 percent of the Antarctic ice is located in the West Antarctic Ice Sheet. The glaciers are situated in a large bowl, with their bases below sea level. As the ice shrinks back into the bowl, it retreats into deeper water, causing the glaciers to destabilize. The glaciers serve to hold the more stable parts of the ice sheet, which is the size of Greenland, in place. The collapse that is now taking place threatens the entire West Antarctic Ice Sheet.
This week, two papers were published in the journal Geophysical Research Letter and Science. Each employed a different approach to come to the same conclusion. Because of the glaciers shrinking into deep valleys, there are no ridges or mountains that would otherwise stop or impede the pace of the melt. One study has been tracking the largest glaciers in the region for the past forty years. By utilizing direct observation of the ice, it concluded that the ice is unstoppable. The other study relies on computer models to predict the melt of the Thwaites Glacier, the largest ice river in West Antarctica.
Researchers suspect that the melt is from the bottom up. A change in wind patterns is believed to be driving warm water beneath the glaciers, undermining their foundations.
For the last half century, the Antarctic Peninsula has been warming and West Antarctica has been getting steadily warmer for the past three decades.
In the short term, the rise in sea level will be relatively small, according to a the Thwaites Glacier model published in Science. Lead study author Ian Joughin, a glaciologist at the University of Washington’s Applied Physics Laboratory said, “Over the next few centuries, the rate of sea level rise will be moderate.” However, based on the rapid retreat observed in the past 40 years, the rise in sea level will likely exceed previous projections of a sea-level rise of 3 feet by 2100. And if all of Antarctica melts, the collapse is predicted to result in a rise of 11 – 13 feet.
Satellite observations have led to the conclusion that there is a common thread causing the retreat of the glaciers, which include Pine Island Glacier, Thwaites Glacier, as well as the Haynes, Smith and Kohler glaciers. Rignot said, “One of the most striking features is they have been reacting almost simultaneously. We do think this is related to climate warming.”
While it could take another 200 – 900 years for the glaciers to completely melt, the effect on the environment will be significant long before that. In the National Climate Assessment, released last week, scientists have dire predictions for the Chesapeake Bay. “As sea levels rise, the Chesapeake Bay region is expected to experience an increase in coastal flooding and drowning of …wetlands.” Those wetlands protect against storm surge. The assessment cites a litany of problems associated with climate change that we are already acquainted with and that will get worse as time goes on: more sea-level rise, flooding, storm surges, precipitation and heat waves in the Northeast sector of the country. Water shortages and hurricanes are to be expected in the Southeast and the Caribbean, while the Southwest will endure droughts and wildfires.
And yet, in the face of all of the science, in the face of what we see nearly every day on our television screens, the climate change deniers in Congress continue to insist that the reports are part of a political agenda rather than hard science. Sen. Jim Inhofe (R-OK) noted that the release of the independent reports seem timed to coincide with a Senate debate on the issue of the Keystone XL Pipeline. “With this report, the president is attempting to once again distract Americans from his unchecked regulatory agenda that is costing our nation millions of job opportunities and our ability to be energy-independent.”
Cato Institute researchers Paul Knappenberger and Patrick Michaels issued a statement pronouncing the assessment “biased towards pessimism” and stated it is a justification for “federal regulation aimed towards mitigating greenhouse gas emissions.” The Cato Institute is a conservative think tank founded by Charles Koch, a billionaire who has made part of his fortune from fossil fuels and who is a staunch denier of climate change, its cause and its effects.