Antarctic ice is melting regardless of human actions

Damage to nature has been done, claim more and more experts. The West Antarctic ice sheet will continue to melt in this century, no matter how much humanity reduces emissions of gases causing our planet's warming, according to researchers from the British Antarctic Survey. This will lead to further increases in sea levels in the coming decades. A new study, published in the journal Nature Climate Change, found that no matter the degree of warming this century, the melting of the West Antarctic ice sheet will accelerate as warmer water from the Amundsen Sea erodes the ice shelves at the ocean's edge. These ice shelves support the ice further inland, acting as a cork that prevents their flow into the ocean. Even in the most optimistic scenario of a 1.5-degree Celsius warming above pre-industrial levels, the ice will melt three times faster in this century than in the previous century. "Emissions reductions can help prevent the worst-case melting scenario, but beyond that, mitigation has minimal impact," said the study's lead author, Kaitlin Naughten, a computer modeler of ocean ice at the British Antarctic Survey. "It seems we may have lost control," she added. The disintegration of the West Antarctic ice sheet is one of the nine "tipping points" for global climate that scientists identified in 2009. Crossing these environmental red lines would be catastrophic for life on Earth. Scientists from an international team stated in 2022 that the "point of no return" for the West Antarctic ice sheet may have already been exceeded with just a 1.1-degree Celsius warming above pre-industrial levels.

If the ice sheet were to melt completely, the global average sea level would rise by more than a meter. Researchers conducted simulations on the UK's national supercomputer to assess ocean temperature increases under different warming scenarios based on a single model. The results "should be treated with caution as different models and even ensembles of the same model can provide different answers," said Tiago Segabinazzi Dotto, a senior scientist at the UK National Oceanography Centre, who was not involved in this study. However, he noted that the new results align with other research suggesting the imminent collapse of the ice shelves in the Amundsen Sea. These include the Thwaites Glacier, about which scientists announced in February that warm water had begun to intrude at its weakest points. Ice across the entire "White Continent" is at risk of disappearing as climate change intensifies. This winter, sea ice around Antarctica recorded the lowest extent ever in terms of maximum coverage. A study published earlier this month found that approximately 40% of ice shelves in Antarctica have significantly shrunk in the past 25 years.