Recent research has highlighted the potential impact of individual weather events on the world’s largest ice sheets and, consequently, on sea level rise. A heat wave in Greenland and a storm in Antarctica have raised concerns about the long-term effects of such events, especially in the context of a warming climate.
According to the Intergovernmental Panel on Climate Change (IPCC), global sea levels are projected to rise by 28 cm to 100 cm by 2100. This wide range of estimates underscores the uncertainty surrounding future sea level rise and its potential implications for millions of people worldwide.
The rising sea level is attributed to two main factors: the expansion of water as it warms and the melting or sliding of the world’s largest ice sheets in Antarctica and Greenland. While the former accounts for about a third of the expected sea-level rise, the latter, which occurs at a relatively slow pace, will continue to contribute to rising sea levels for centuries.
Scientists have long acknowledged the possibility of sudden accelerations in the rate of ice loss from Greenland and Antarctica, which could result in significantly higher sea-level rise, potentially exceeding a metre in a century. Such accelerations, once initiated, may be irreversible, posing a substantial risk to coastal regions.
However, the exact likelihood of these sudden accelerations remains uncertain, although historical evidence suggests that similar events occurred approximately 130,000 years ago during a period of global temperatures comparable to the present day. This underscores the importance of gaining a clearer understanding of the Antarctic and Greenland ice sheets to enhance predictions of sea level rise.
The recent study, conducted by an international team of 29 ice-sheet experts, emphasizes the need to identify weather and climate changes that could lead to abrupt increases in the speed of mass loss from the ice sheets. By improving our understanding of these processes, we can better predict and prepare for the potential impacts of sea level rise.