An interdisciplinary team of researchers from NTU Singapore, and Delft University of Technology (TU Delft), The Netherlands, has projected that if the rate of global CO2 emissions continues to increase and reaches a high emission scenario, sea levels would as a result very likely rise between 0.5 and 1.9 metres by 2100. The high end of this projection's range is 90 centimetres higher than the latest United Nations' global projection of 0.6 to 1.0 metres*.
The very likely range (90 per cent probability for the event to occur), reported by the NTU team in the scientific journal Earth's Future, complements sea-level rise projections reported by the United Nation's Intergovernmental Panel on Climate Change (IPCC), which only assessed the probability of projections up to a likely range (66 per cent probability).
Current sea-level projections rely on a range of methods to model climate processes. Some include well-understood phenomena like glacier melting, while others incorporate more uncertain events, such as abrupt ice shelf collapse.
As a result, these models produce varying projections, making it difficult to estimate reliable extreme sea-level rise. This ambiguity in projections from different methods has prevented the IPCC from providing very likely ranges for sea-level projections - a valuable standard in managing risk.
To overcome this challenge and to address the uncertainties in current sea-level rise projections, NTU researchers developed a new, improved projection method known as the "fusion" approach. This approach combines the strengths of existing models with expert opinions, offering a clearer, more reliable picture of future sea-level rise.
The research team believes their new method fills a critical gap for reliable information, complementing the IPCC's latest report.
* Projection based on the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report. The IPCC is a United Nations body that provides authoritative scientific assessments on climate change. https://www.ipcc.ch/report/ar6/wg1/chapter/chapter-9/
