New research suggests that the rapid melting of West Antarctica’s ice shelves is on an irreversible path due to the acceleration of human-caused global warming. Even if ambitious global heating targets are met, this troubling development has potentially devastating consequences for sea level rise across the globe.
Published in the journal Nature Climate Change, a recent study indicates that substantial ocean warming and ice shelf melting in West Antarctica are inevitable, regardless of efforts to limit global warming. These ice shelves, which extend into the ocean from the end of glaciers, play a crucial role in holding back land-based ice and slowing its flow into the sea, thus acting as a vital defense against rising sea levels. However, as these ice shelves melt, they become thinner and lose their buttressing capabilities.
While there has been growing evidence that ice loss in West Antarctica may be irreversible, uncertainties persisted regarding the extent to which climate policies could mitigate this phenomenon.
The study focused on “basal melting,” where warm ocean currents melt ice from below. It analyzed the rate of ocean warming and ice shelf melting under different climate change scenarios, ranging from ambitious goals to limit global warming to worst-case scenarios involving extensive use of planet-heating fossil fuels. The results showed that even if the world manages to limit temperature rise to 1.5 degrees Celsius, climate change could cause ocean warming at three times the historical rate. Even significant reductions in planet-heating pollution will have limited power to prevent the collapse of the West Antarctic ice sheet.
Kaitlin Naughten, lead author of the study and an ocean modeler with the British Antarctic Survey, expressed concern, stating, “It appears that we may have lost control of the West Antarctic ice melting over the 21st century.”
West Antarctica already contributes the most to global sea level rise and has enough ice to raise sea levels by an average of 5.3 meters, or more than 17 feet. It is home to the Thwaites Glacier, known as the “Doomsday glacier,” as its collapse could significantly raise sea levels, necessitating coastal communities and low-lying island nations to adapt to rising sea levels.
While the study focused on ice shelf melting and did not directly quantify its impact on sea level rise, it is expected that sea levels will increase as West Antarctica accelerates the loss of ice into the ocean.
The findings are sobering, as they confirm the committed nature of sea level rise for the next century, affecting coastal cities worldwide. Halting rapid ice melting will require not only reducing planet-heating pollution but also addressing existing buildup, which poses a significant challenge.
Though some scientists advise caution regarding the study’s findings, it aligns with previous research and underscores the need for policymakers to consider its implications.
The study’s authors acknowledge its limitations in predicting future rates of melting in West Antarctica but are confident in their conclusion that ice shelf melting is now unavoidable.
While the outlook is dire, there remains hope in efforts to reduce fossil fuel emissions to mitigate devastating impacts in other regions and around the world.