If greenhouse gas emissions continue at the current rate, by 2100 the sea level on Earth could have risen by up to one metre, with increasing damage from storm surges and extreme weather events. The prospect comes from a study published in the journal “Earth System Science Data”, in which Professors Matteo Vacchi (Photo) of the University of Pisa and Alessio Rovere of the Ca’ Foscari University of Venice were the first authors. The research put together all existing data on sea levels during the last interglacial period, 125,000 years ago, the last one in which the Earth was slightly warmer than today, about 1-1.5 degrees on a global scale and 3-5 at the poles. According to the online atlas created by the researchers, sea levels at that time were between 3 and 9 metres higher than now.
“During the interglacial period, climatic conditions were due to a change in the Earth’s orbital configuration,” explains Matteo Vacchi. “Today's climate warming, on the other hand, derives mainly from the increase of carbon dioxide emissions in the atmosphere due to the anthropogenic effect.
Globally, the most vulnerable areas to the sea level rise are the atolls in the Pacific and the large coastal plains of south-east Asia. As for the Mediterranean, the Venice lagoon, the upper Adriatic, and in general the large coastal plains, e.g., the Volturno in Naples, but also the Pisa plain in Tuscany, are particularly vulnerable, and for North Africa the flat coastal areas of Tunisia, Morocco and the Nile Delta.
Primarily responsible for rising seas would be the melting of the planet’s two large polar ice sheets, Greenland, and Antarctica. From this point of view, the data put together by the study are fundamental for outlining future climate scenarios. If the entire ice sheet currently covering Greenland were to melt, the global sea level would rise by about 7 metres. If, on the other hand, the entire Antarctic ice sheet were to melt, the sea would rise by an additional 58 metres.
"There have been periods on Earth, when the sea level was above the current one," Vacchi concludes, "but what is worrying today is the increasing rate, i.e., the acceleration that has taken place over the last 150 years, coinciding with the start of the industrial revolution that has greatly increased greenhouse gases into the atmosphere.
The work published in the journal “Earth System Science Data” is the result of the WARMCOASTS project funded by the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. ERC-StG-802414), won by Professor Alessio Rovere.