The Uncertain Future of Antarctica’s Melting Ice
Excerpt: A new multidisciplinary, international research program aims to tackle one of the grand challenges in climate science: resolving the Antarctic Ice Sheet’s contribution to future sea level rise. ...Among the most visible effects of anthropogenic global warming are rising seas around the world: Since 1880, the global mean sea level (GMSL) has increased by 20 centimeters. ...sea level globally will continue to rise well beyond the 21st century, even if warming of the planet is stabilized below the target set by the Paris climate agreement in 2015 of 2°C above the preindustrial average. ...An estimated 800 million people are likely to experience impacts of high-tide flooding by the end of the 21st century, even if the Paris climate agreement target is met. In many coastal settings, even a small increase in baseline sea level can substantially increase the frequency and magnitude of flooding during high tides, storm surges, and extreme weather. The United Nations estimates that the potential costs of damage to harbors and ports alone from this flooding could be as high as $111.6 billion by 2050 and $367.2 billion by the end of the century. ...If global carbon emissions follow the high-emission Shared Socioeconomic Pathway (SSP) 5–8.5, meaning atmospheric carbon dioxide levels rise above 1,000 parts per million by 2100 ..., melting Antarctic ice would contribute 14–32 centimeters (13th–87th percentiles) to an overall GMSL rise of 62–101 centimeters... according to a statistical assessment of numerical model projections [e.g., Edwards et al., 2021].…