New Model Assesses Extent Of Sea Level Rise By 2100
January 7, 2013

New Model Assesses Extent Of Sea Level Rise By 2100

Lawrence LeBlond for - Your Universe Online

Two professors with the Intergovernmental Panel on Climate Change (IPCC) have taken on a new approach to assess future sea level rise due to the world´s melting ice sheets.

Their study, published this week in Nature Climate Change, is the first of its kind to use structured expert elicitation (EE) along with an approach that mathematically pools other experts´ opinions to gain a clear picture on ice sheet melting. Researchers also use EE in other fields, such as volcanic eruption forecasting and the spread of vector borne diseases.

More than 99 percent of the Earth´s glacier ice is contained within the Antarctic and Greenland ice sheets. If both these ice sheets were to completely melt, oceans would rise more than 200 feet.

Professor´s Jonathan Bamber and Willy Aspinall noted that these two ice sheets are the largest potential source for future sea level rise; yet they both also possess the largest uncertainty over their future behavior. The duo also notes that there are some unique challenges in predicting the future responses of these ice sheets using numerical models.

Using their model, Bamber and Aspinall found that the median estimate for the sea level contribution from ice sheets by the end of this century was 11.5 inches with a 5 percent probability that it could exceed 33 inches. When they combined their model estimates with other sources of seal level rise, it implied a risk of rise of greater than 39 inches by 2100.

The IPCC report provided figures ranging from 7 to 33 inches for six possible scenarios.

The two researchers also found that scientists, as a group, were highly uncertain about the cause of the recent increase in ice sheet loss observed by satellites. Science experts are also unsure whether this loss was part of a long-term trend or due to short-term fluctuations in the climate.

“This is the first study of its kind on ice sheet melting to use a formalized mathematical pooling of experts' opinions. It demonstrates the value and potential of this approach for a wide range of similar problems in climate change research, where past data and current numerical modeling have significant limitations when it comes to forecasting future trends and patterns,” Bamber said in a statement.

The IPCC study was partially funded by Ice2sea–a major EU-funded program to improve future global sea level rise projections.