Scientists have made a groundbreaking discovery about Antarctica’s Thwaites Glacier, also known as the “Doomsday Glacier,” which has the potential to cause catastrophic sea level rise. The glacier, which is the world’s widest and approximately the size of Florida, has been losing ice at an accelerating rate since the 1970s. However, due to limited satellite data, scientists were unsure of when significant melting began.
In a recent study published in the Proceedings of the National Academy of Sciences, researchers analyzed marine sediment cores extracted from beneath the ocean floor to reconstruct the glacier’s past. They found that Thwaites began retreating rapidly in the 1940s, most likely triggered by a strong El Niño event, a natural climate fluctuation that tends to have a warming impact. This retreat has continued ever since, possibly due to the increasing influence of human-caused global warming.
The implications of Thwaites’ fate are significant on a global scale. Currently, the glacier contributes 4% of sea level rise as it sheds billions of tons of ice into the ocean each year. If it were to completely collapse, sea levels could rise by more than 2 feet. However, Thwaites also plays a crucial role in stabilizing the West Antarctic Ice Sheet. Its collapse would undermine the stability of the ice sheet, which holds enough water to raise sea levels by at least 10 feet, resulting in catastrophic global flooding.
The study’s findings align with previous research on the neighboring Pine Island Glacier, another large ice stream in Antarctica that also began retreating rapidly in the 1940s. This suggests that what is happening to Thwaites is not an isolated incident but part of a larger context of climate change.
To understand Thwaites’ history over the past 12,000 years, scientists collected ocean sediment cores from various depths using an icebreaker vessel. These cores provided a historical timeline, with each layer offering information about the ocean and ice dating back thousands of years. By analyzing and dating the sediments, researchers were able to determine when significant melting began. They concluded that an extreme El Niño event likely triggered Thwaites’ retreat, exacerbating the glacier’s already ongoing melting phase.
The study’s findings are alarming because they suggest that once significant changes are set in motion, it becomes challenging to halt or reverse them. James Smith, a marine geologist at the British Antarctic Survey and co-author of the study, states that once an ice sheet retreat begins, it can continue for decades, even if the initial trigger does not worsen. While similar retreats have occurred in the past, those ice sheets eventually recovered and regrew. However, Thwaites and Pine Island glaciers show no signs of recovery, indicating the growing influence of human-caused climate change.
Ted Scambos, a glaciologist at the University of Colorado Boulder, affirms that this study provides additional details about how Thwaites’ retreat began. He explains that the glacier was already close to being unstable and was further impacted by natural events like El Niño. The warming climate trend then accelerated the widespread retreat observed today.
Martin Truffer, a physics professor at the University of Alaska Fairbanks, emphasizes that this research demonstrates how small continuous changes in climate can lead to significant shifts in glacier state. He highlights that humans are altering the climate, and this study underscores the importance of understanding the potential consequences for vulnerable glaciers like Thwaites.
Antarctica is often referred to as the “sleeping giant” because scientists are still uncovering its vulnerability as humans continue to warm the atmosphere and oceans. Julia Wellner, an associate professor of geology at the University of Houston and one of the study’s authors, focuses on the past rather than the future. However, she acknowledges that this study provides crucial context for understanding the fate of the ice in this vital region of Antarctica. It demonstrates that even if the trigger for rapid melting ends, the response may not cease. Therefore, if the ice is already in retreat today, it may continue to do so even if warming is halted.
The findings of this study shed light on the alarming past of Antarctica’s Thwaites Glacier and its potential impact on sea level rise. They emphasize the urgent need for further research and action to mitigate the effects of climate change and protect vulnerable regions from catastrophic flooding. The fate of Thwaites serves as a stark reminder of the consequences of human-caused global warming and the importance of preserving our planet’s delicate ecosystems.