Recent research highlights alarming and rapid changes occurring in Antarctica, posing significant risks to Australia unless immediate action is implemented. An international study, involving scientists from the University of NSW and the Australian National University, emphasises that the climate-induced transformations in Antarctica are interconnected and accelerating.
Dr Nerilie Abram, the lead author and chief scientist at the Australian Antarctic Division, stresses the urgent need for preparation to address the widespread impacts. She points out that rapid changes have already been observed across Antarctica’s ice, oceans, and ecosystems, with further worsening expected for every increment of global temperature rise.
Co-author Professor Matthew England from UNSW noted the potential consequences for Australia, including rising sea levels affecting coastal communities, a warmer and deoxygenated Southern Ocean that will struggle to absorb carbon dioxide, exacerbating warming in Australia and beyond, and increased regional warming due to the loss of Antarctic sea ice.
Dr Abram warned that the recent significant decline in sea ice heightens risks for floating ice shelves, making them more vulnerable to collapsing under wave impacts. She particularly highlighted the precarious state of the West Antarctic Ice Sheet (WAIS), which faces severe risk of collapse due to rising carbon dioxide levels. If this occurs, it could result in sea level rises exceeding three metres, jeopardising coastal cities globally.
The impact of reduced sea ice extends beyond human concerns to wildlife, with species such as emperor penguins particularly at risk of extinction. These penguins depend on stable sea ice for breeding, and significant losses to their populations have already been documented. Other affected species include krill, seals, and various penguin species, along with foundational ocean plants like phytoplankton, which are crucial for the marine food web, suffering from warming and acidification.
Additionally, Dr Abram indicated that both the shrinking sea ice and a slowdown in deep ocean circulation are proving to be more sensitive to warming than previously believed. As the extent of sea ice decreases, it changes how much solar heat remains in the climate system, further exacerbating warming in Antarctica.
Looking ahead, Dr Abram asserts that the only effective solution to prevent abrupt changes and their extensive implications is rapid reduction of greenhouse gas emissions, aiming to limit global warming to as close to 1.5 degrees Celsius as feasible. She urged that these observable changes in Antarctica must be incorporated into future climate change strategies by governments, businesses, and communities, especially in Australia. Immediate concerted efforts are essential to mitigate these escalating impacts on both ecosystems and human societies.