Sea level rise of one meter within 100 years

Niels Bohr Institute (Denmark): New research indicates that the ocean could rise in the next 100 years to a meter higher than the current sea level – which is three times higher than predictions from the UN’s Intergovernmental Panel on Climate Change, IPCC.

…The great uncertainty in the calculation of the future rise in the sea level lies in the uncertainty over how quickly the ice sheets on land will melt and flow out to sea. The model predictions of the melting of the ice sheets are the basis for the Intergovernmental Panel on Climate Change’s predictions for the rise in sea level are not capable of showing the rapid changes observed in recent years. The new research has therefore taken a different approach.

“Instead of making calculations based on what one believes will happen with the melting of the ice sheets we have made calculations based on what has actually happened in the past. We have looked at the direct relationship between the global temperature and the sea level 2000 years into the past”, explains Aslak Grinsted, who is a geophysicist at the Centre for Ice and Climate at the Niels Bohr Institute at the University of Copenhagen.

With the help of annual growth rings of trees and analysis from ice core borings researchers have been able to calculate the temperature for the global climate 2000 years back in time. For around 300 years the sea level has been closely observed in several places around the world and in addition to that there is historical knowledge of the sea level of the past in different places in the world.

By linking the two sets of information together Aslak Grinsted could see the relationship between temperature and sea level. …In the current situation with global warming, Aslak Grinsted believes, that the sea level will rise with the same speed – that is to say a meter in the span of the next 100 years.

The curve shows the sea level from the year 200 to the year 2100. The future rise in sea level of 1 meter is calculated from global warming of 3 degrees in this century. The dotted line indicates the UN Intergovernmental Panel on Climate Change’s prediction. The blue shade indicates the calculations’ degree of uncertainty. (Aslak Grinsted, Niels Bohr Institute)