Two hundred sixty feet of sea level rise. The number is breathtaking, and yet matter-of-fact: It simply describes how much oceans would rise if all of the planet's great ice sheets -- all of Greenland, all of Antarctica -- were to melt entirely and fall into the oceans.
Nobody thinks this will happen in our lifetimes. However, if we let global warming rip, and move into a hothouse world with enough heat trapped by atmospheric greenhouse gases, it could someday. After all, the planet has been there before -- in the late Cretaceous period, some 80 million years ago, sea levels were 50 to 70 meters higher, and rising.
In the meantime, we can imagine. Hence I give you this artistic rendering of what could happen to Los Angeles, from Seattlite and landscape architect Jeffrey Linn, who runs the website Spatialities.com:
Here's his image of Vancouver:
Note that Linn is not a scientist: He has a background in geography, mapping, and urban planning, and notes that he takes some "artistic license with anything over 225 or so feet." He explains that he started making these maps after being inspired by another blogger, Burrito Justice, who visualized San Francisco under 200 feet of sea level rise. To make the maps, Linn simply sets the sea level to 260 feet, and then uses data from the U.S. Geological Survey to determine the elevations for various parts of the city in question. He also sells his maps as 24 x 24 inch posters, and has seen some interest, though he confesses, "I'm not going to retire on this."
Certainly there is something that hits you in the gut about seeing your city submerged -- a feeling that, so far, Linn has largely limited to West Coasters. He hasn't done submerged maps for many East Coast or global cities, though he confesses, "it would be interesting to maybe do an atlas of all of the iconic cities around the world, and take a look at places like Rome, and Paris, and London."
"When I was putting together the first one, the Seattle map," Linn says, "I was showing these to my daughter Vivian -- she was 7 years old at the time, and she was horrified to see what would happen to her city, this place she had lived in all her life. And for months, she would not even look at the map, because it scared her too much."