Phys.org December 17, 2024 Human-induced climate change, and other human activities in Antarctica and the Southern Ocean region are leading to several potential interacting tipping points with major and irreversible consequences. An international team of researchers (UK, Australia) examined eight potential physical, biological, chemical, and social Antarctic tipping points – Ice sheets, Ocean acidification, Ocean circulation, Species redistribution, Invasive species, Permafrost melting, Local pollution, and the Antarctic Treaty System. They discussed the nature of each potential tipping point, its control variables, thresholds, timescales, and impacts, and focused on the potential for cumulative and cascading effects because of their interactions. Their […]
Tag Archives: Climate tipping point
New ice core data provide insight into climate ‘tipping points’ during the last Ice Age
Phys.org October 22, 2024 Reconstructions of Earth’s past climate show evidence for instability and abrupt change, which are of great scientific and societal importance. The Dansgaard–Oeschger (DO) oscillation of the last Ice Age, which is most clearly observed in Greenland ice cores, is the prime example of such instability. An international team of researchers (Oregon State University, Pennsylvania State University, University of Miami, University of Colorado, Denmark, UK) presented ice-core records from south and coastal east Greenland to calibrate the local water isotope thermometer and provided a Greenland-wide spatial characterization of DO event magnitude. They used a series of idealized […]
New tipping point discovered beneath the Antarctic ice sheet
Phys.org June 25, 2024 Recently published studies of the complex hydrography of grounding zones suggest that warm ocean water can intrude large distances beneath the ice sheet, with dramatic consequences for ice dynamics. Researchers in the UK developed a model to capture the feedback between intruded ocean water, the melting it induces and the resulting changes in ice geometry showing a sensitive dependence of the grounding-zone dynamics on this feedback: as the grounding zone widens in response to melting, both temperature and flow velocity in the region increase, further enhancing melting. They found that increases in ocean temperature could lead […]
Study: Four major climate tipping points close to triggering
Phys.org September 11, 2022 Climate tipping points (CTPs) occur when change in large parts of the climate system become self-perpetuating beyond a warming threshold. Triggering CTPs leads to significant, policy-relevant impacts, including substantial sea level rise from collapsing ice sheets, dieback of biodiverse biomes such as the Amazon rainforest or warm-water corals, and carbon release from thawing permafrost. An international team of researchers (Sweden, UK, Germany) provides a comprehensive reassessment of all the nine policy-relevant tipping elements and their CTPs that were originally identified by Lenton et al. (2008). The team updated assessment of the most important climate tipping elements […]