New protocol improves predictions of sea-level rise

Published: 4 September 2014

Marc Hijma of Deltares has devised a new protocol that improves forecasts of regional sea-level rise. Using the protocol at the global level will represent an enormous step forwards in predicting sea-level change. The new protocol will be included in the Handbook of Sea-Level Rise, which will be published in March 2015

Sea-level index point at 15 m depth in a construction pit below Rotterdam-Blijdorp. De browngray-lightgray-browngray band at the same height as the handle of the shovel forms the marker of sea level 8500 years ago.

Objective error analysis for every point

Marc Hijma explains: ‘In Scotland, I will be presenting a new protocol for entering separate, objective, error analyses for every point in databases with regional geological sea-level data. Those error analyses are extremely important because they improve our forecasts of regional sea-level rise. Ultimately, the idea is to establish a planetary database. In that case, we will be talking about tens of thousands of data points.’

Forty global experts in the field of sea-level rise will be meeting in September in Scotland to discuss topics that will include predicting rises in sea levels. Marc Hijma, an expert with Deltares, is the only person from a research institute to be invited to this PalSea conference. The other experts are all from universities.

The difference with the present approach

Of course, there have already been regular predictions about the extent of sea-level change. What is the difference with the current approach to forecasting? Sea-level rise varies from region to region, and current forecasts do not take this into account. ‘Sound regional predictions will allow us to take the best precautions in any given location. So it’s important to have those predictions,’ explains Marc.

Forecasts of sea-level rise use historical information

Marc Hijma is an earth scientist, which is useful because our forecasts of sea-level rise depend largely on information about the past. Throughout the world, there are clues showing how high or low seas have been at given times. Tens of thousands of these data points have been collected over recent decades. The new protocols can be used to organise these points at the global level to determine the history of sea levels and to produce better forecasts.