When the waters start to rise, how will coastlines around the globe be affected? A clever mash-up of Google Maps and NASA data gives a graphic illustration of what could happen if sea levels rise by up to 14 metres.
George Murphy, who commented on my North Polar Meltdown post, asked if I knew of any maps showing what might happen to coastlines when sea levels begin to rise. He’d had difficulty finding any. I didn’t know of any either, so I did a Google search for nasa climate change maps and found a site put together by Alex Tingle. Located at flood.firetree.net, Alex has managed to combine Google Maps with NASA data to produce a zoomable global map that can display the extent of coastline submersion when sea levels rise, up to 14 metres above current levels. The image on the left shows how London would be afflicted if the river Thames expanded under the pressure of an additional 14 metres of water (click these images to go to the site and see the maps there).
The shaded blue areas on this image show how a significant chunk of eastern England — and a sizeable area of Holland — would disappear if the North Sea rose by 14 metres:
It’s not a perfect system, as Alex discusses at his blog — but it gives enough of an indication to give us all pause for thought.
My part of the world, the levels of north Somerset, has often been flooded in the past — notably, in 1607 — and this image shows how ravaged the area would be if sea levels rose by 14 metres. The shaded area closely coincides with the low-lying area that has been flooded in the past. Of course, when the land floods because of exceptionally high spring tides or crashing storm surges, the body of water subsides quite rapidly (though it leaves utter devastation in its wake, the effects of which last for many years). What this picture shows is the extent of the permanent loss of land that would occur if sea levels rose by 14 metres. My village of Banwell, about four miles inland from the current coastal town of Weston-super-Mare, will be nestling on the shoreline of the new coast. Weston itself will disappear. Worlebury Hill, just to the north of Weston, will become an island. Glastonbury, some ten miles inland, will also find itself all-but surrounded by water and accessible only by a narrow strip of land (currently the A39). Burnham-on-Sea will become Burnham-under-sea; the ancient settlements of Highbridge and Bridgwater — and many more villages and hamlets — will be no more.
Because of limitations in the way Alex has been able to overlay the NASA data on the Google Maps, they can only go up to an increase of 14 metres. This is probably more than enough for current needs — some say there’s going to be about one metre of sea level rise by 2100 — but if most of the ice on Greenland and the ice on the Antarctic continent were to melt away during the centuries to come, then a rise in excess of 25 metres is not out of the question.
And some estimate that if all the ice presently existing on earth melted, sea levels would rise by a staggering 70 metres.
Let’s hope we never go there.
Read my Climate Change posts in chronological order by using the Climate Change Log.