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, warns a new study.
An international study led by Nanyang Technological University, Singapore (NTU Singapore) scientists has found that the sea level could rise by more than a metre by 2100 if emissions targets 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, according to a statement.
In a scenario where global warming is limited to 2 degrees Celsius above pre-industrial levels, the experts estimated a rise of 0.5 meters by 2100 and 0.5 to 2 meters by 2300. In a high-emissions scenario with 4.5 degree Celsius of 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.
Professor Benjamin Horton, Acting Chair of NTU’s Asian School of the Environment, who led the survey, said in the statement that sea-level rise projections and knowledge of their uncertainties are vital to make informed mitigation and adaptation decisions.
He said: “The complexity of sea-level projections, and the sheer amount of relevant scientific publications, make it difficult for policymakers to get an overview of the state of the science. To obtain this overview, it is useful to survey leading experts on the expected sea-level rise, which provides a broader picture of future scenarios and informs policymakers so they can prepare necessary measures.”
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.
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