The level of the Mediterranean Sea is rising rapidly and could increase by up to half a metre in the next 50 years, scientists in Spain have warned.
Scientists noted sea temperatures had also risen significantly
A study by the Spanish Oceanographic Institute says levels have been rising since the 1970s with the rate of increase growing in recent years.
It says even a small rise could have serious consequences in coastal areas.
The study noted that the findings were consistent with other investigations into the effects of climate change.
The study, entitled Climate Change in the Spanish Mediterranean, said the sea had risen "between 2.5mm and 10mm (0.1 and 0.4in) per year since the 1990s".
If the trend continued it would have "very serious consequences" in low-lying coastal areas even in the case of a small rise, and "catastrophic consequences" if a half-metre increase occurred, the study warned.
Global climate change
Scientists noted that sea temperatures had also risen significantly by 0.12 to 0.5C since the 1970s.
Sea level rise is a key effect of global climate change. There are two major contributory effects: the melting of ice, and expansion of sea water as the oceans warm.
Last month, the Intergovernmental Panel on Climate Change said the world's sea levels would rise by a maximum of 59cm this century.
Some scientists believe this is an under-estimate as it does not include the influence of "enhanced" ice-cap melting, where warmer waters lubricate the flow of ice into the oceans.