Projections for Sea Level Rise Exceed IPCC Estimates
An international study led by Nanyang Technological University (NTU) in Singapore has found that the global mean sea-level rise could exceed one meter by 2100 and five meters by 2300 if global targets on emissions are not achieved.
The study used projections by more than 100 international experts for the global mean sea-level changes under two climate scenarios – low and high emissions. In a scenario where global warming is limited to 2 degree Celsius above pre-industrial levels, the experts estimated a rise of 0.5 meters by 2100 and 0.5 to two meters by 2300. In a high-emissions scenario with 4.5 degree Celsius warming, the experts estimated a larger rise of 0.6 to 1.3 meters by 2100 and 1.7 to 5.6 meters by 2300.
The projections of sea-level rise exceed previous estimates by the International Panel on Climate Change (IPCC).
“We know that the planet will see additional sea-level rise in the future,” says co-author Dr Andra Garner, Assistant Professor of Environmental Science at Rowan University in the US. “But there are stark differences in the amount of sea-level rise experts project for low emissions compared to high emissions. This provides a great deal of hope for the future as well as a strong motivation to act now to avoid the more severe impacts of rising sea levels.”
The study is based on the informed opinions of 106 sea-level experts. The 106 experts who participated in the survey were chosen as they were among the most active publishers of scientific sea-level studies (at least six published papers in peer-reviewed journals since 2014) identified from a leading publication database.
In response to open-ended questions, the climate change experts identified the Greenland and Antarctic Ice Sheets as the greatest sources of uncertainty. These ice sheets are an important indicator of climate change and driver of sea-level rise. Satellite-based measurements show the ice sheets are melting at an accelerating rate. However, the experts also noted that the magnitude and impact of sea-level rise can be limited by successfully reducing emissions.
Professor Benjamin Horton, Acting Chair of NTU’s Asian School of the Environment, led the survey which was published in Nature Partner Journals Climate and Atmospheric Science. The collaborative project included researchers from The University of Hong Kong, Maynooth University (Ireland), Durham University (UK), Rowan University, Tufts University (US), and the Potsdam Institute for Climate Impact Research (Germany).