UNITED STATES: Greenland’s ice sheet, once thought to be an impregnable fortress of ice, has been found to have experienced complete melting within the last half a million years, leading to a rise in global sea levels of at least 1.5 meters, according to a groundbreaking study by an international team of scientists.
In a reevaluation of Greenland’s glacial history, researchers from the University of Vermont (UVM) and other institutes have uncovered compelling evidence indicating that the ice sheet vanished entirely in the past, leaving the land beneath it covered in vegetation.
The findings, published in the esteemed journal Science, have profound implications for our understanding of climate change and the potential consequences of ice melt.
The study employed state-of-the-art luminescence technology and rare isotope analysis to examine an ice core retrieved from Greenland. Led by UVM scientists Paul Bierman and Tammy Rittenour, the research delved deep into the ice core’s sediment to reconstruct the region’s ancient climate.
The luminescence analysis, conducted in Dr. Rittenour’s lab at Utah State University, involved studying rock and sand samples from the sediment. By analyzing the luminescence signal, the scientists were able to determine periods when the sediment was exposed to sunlight and when it was transported by wind or water before being re-buried under ice or rock.
The results revealed that Greenland’s ice-free periods occurred less than 14,000 years ago, providing valuable insights into the ice sheet’s historical behavior.
This suggests that Greenland is far more sensitive to climate change than previously believed, making it particularly susceptible to future warming and ice loss.
“The past is preserved in twelve feet of frozen soil, and it paints a concerning picture of a warm, wet, and largely ice-free future for our planet,” warns Paul Bierman. “Unless we take drastic measures to lower carbon dioxide concentrations in the atmosphere, we could be facing meters of sea level rise, potentially tens of meters.”
The consequences of such a sea level rise would be catastrophic for coastal regions worldwide. Presently, about 23 feet of potential global sea level rise is associated with Greenland’s ice, placing millions of people living near the coast at risk.
The findings serve as a wake-up call for the urgency of tackling climate change. As Dr. Rittenour highlights, “Four hundred thousand years ago, there were no cities on the coast, and now there are cities on the coast.”
With cities like New York City, Boston, Miami, Amsterdam, and numerous other global population centers situated near sea level, the impact of rising waters could be devastating.
Understanding Greenland’s past is paramount to predicting its ice sheet’s response to climate change. By learning from history, scientists can better anticipate the future and develop strategies to mitigate the risk posed by melting ice.