John Church and Peter Clark write in The Conversation (31.3.16) about what recent research reveals about the implications and impact of rising sea levels as a result of global warming.
‘A recent high-profile study led by US climatologist James Hansen has warned that sea levels could rise by several metres by the end of this century. How realistic is this scenario?
‘We can certainly say that sea levels are rising at an accelerating rate, after several millennia of relative stability. The question is how far and how fast they will go, compared with Earth’s previous history of major sea-level changes.
‘Seas have already risen by more than 20 cm since 1880, affecting coastal environments around the world. Since 1993, sea level has been rising faster still, at about 3 mm per year (30 cm per century).
‘One key to understanding future sea levels is to look to the past. The prehistoric record clearly shows that sea level was higher in past warmer climates. The best evidence comes from the most recent interglacial period (129,000 to 116,000 years ago), when sea level was 5-10 m higher than today, and high-latitude temperatures were at least 2℃ warmer than at present.’