Researchers predict Mediterranean Sea level rise

Climate change and increased greenhouse gases will raise the level of the Mediterranean Sea and ocean temperatures in this area, a Spanish-British research team has forecast. The scientists from the Mediterranean Institute for Advanced Studies (IMEDEA) and the National Oceanography Centre of Southampton in the UK analysed simulations based on three scenarios. Their aim is to predict the sea level, salinity and temperature of the Mediterranean in the 21st century. The study's findings were recently published in the Journal of Geophysical Research-Oceans.

The models used in the study comprised a series of socioeconomic scenarios capable of predicting what lies in store for the area. Concerning the salinity of the area, the models showed that the Mediterranean will become saltier. But the scientists said the forecast is not 100% accurate.

'The variations in salinity in the Mediterranean are controlled by the exchange of water through the Straits of Gibraltar, and this has not been incorporated as an indicator, meaning the related results are not very reliable,' said Dr Marcos and Dr Michael Tsimplis, a researcher at the National Oceanography Centre of Southampton.

According to them, IPCC models have very low spatial resolution. So while they are capable of showing global processes 'reasonably well', the challenge emerges with regional ones, where it is harder for the researchers to 'be sure of the scale of the changes', Dr Marcos said.

Drs Marcos and Tsimplis said the Straits of Gibraltar are not well reproduced in the models. They added that global models cannot calculate the impact of sea level rise in coastal areas 'because of the high level of regional variability for this factor'.

The scientists believe that using high-resolution, regional climate models would resolve this problem, particularly since they would show the Mediterranean straits and oceanic processes (occurring within the ocean's basin and coastal areas) with greater clarity.

European researchers focusing on the prediction of climate change effects at regional level are targeting such a strategy and they believe that predictions made will become more certain over the short term.

IMEDEA is a joint centre run by UIB and the Spanish National Research Council (CSIC).