Communications Earth and Environment, 27 May 2022

Long-term summer warming in the Antarctic Peninsula has increased the severity of Antarctic heatwaves by 25% over the past century, largely as a result of rising human emissions. During February 2020, the Antarctic Peninsula experienced one of the most intense heatwaves ever recorded in Western Antarctica, with temperatures reaching an unprecedented 18.3°C at the Esperanza base. A high-pressure system pushed warm and moist air from the Pacific Ocean over the Antarctic Peninsula, triggering this heatwave. The rapid movement of these air currents through the mountains further intensified local warming. This study underscores that changes in air circulation alone cannot explain the extreme temperature rise during such heatwaves. Rising global temperatures have multiplied the likelihood of Antarctica experiencing intense week-long heatwaves – such as the one observed in February 2020 – by tenfold since the 1950s. These findings suggest that human activity increases the severity of temperature and weather extremes in Antarctica.