For some people, global warming is a hard sell. Temperatures going up by a few degrees doesn't sound all that bad, and even results like drought or increased spread of mosquitos and other pests, while certainly unpleasant, are familiar issues. Mega-problems like whiplash/abrupt climate change, where warming leads to an ice age, can sound more surreal than threatening. But this website might change their minds. It shows something that is obviously warming-related, is already starting to happen (not just a "might happen 50 years down the road" possibility), and is a clear danger to the industrialized world's economies and societies: a seven meter rise in sea levels.
Flood Maps mashes up NASA elevation data and Google Maps, and offers a visualization of the effects of a single meter increase all the way to a 14 meter rise. The default increase of seven meters -- about 23 feet for those who avoid the whole metric thing -- is the amount the world's oceans will rise once Greenland's glacial ice pack melts completely. This melting is already underway, and is happening with startling speed.
[From February:] ... researchers found that [Greenland's] glaciers were traveling faster than anyone had predicted. They also determined that even more northerly glaciers were on the move and that in just 10 years the amount of fresh water lost by all the glaciers had more than doubled from 90 cubic kilometers of ice loss a year to 224 cubic kilometers. "The amount of water Los Angeles uses over one year is about one cubic kilometer," Rignot points out. "Two hundred cubic kilometers is a lot of fresh water."
The map doesn't cover the whole world yet, but does cover most of North America and the Caribbean, as well as most of Western and Central Europe. As expected, a seven meter rise inundates locations like the Netherlands, Louisiana and Florida; perhaps surprisingly, areas like southeast England and inland regions east of San Francisco, while not often thought of as being at risk from rising seas, suffer just as much. Since the site uses Google Maps, you can view the results in both standard map and satellite format -- and seeing the projection of the oceans approaching the doors of (for example) the White House can be sobering.
The amount of sea level rise coming from melting ice sheets today is fairly low: a bit less than a millimeter every year. Another millimeter or more comes from the "thermal expansion" of warmer water. But this amount is very clearly just the pebbles before the avalanche; although it's unlikely that we'd see the full seven meter increase as an abrupt event, as the glaciers melt faster and faster, the oceans will rise more and more. A one meter rise is a distinct possibility within the next couple of decades; seven meters could come far faster than we would expect, or be able to handle.
What makes this all the more troubling is that Greenland isn't the only place that glaciers are melting; the Antarctic glaciers are, too. And there's a helluva lot more glacial ice on Antarctica than on Greenland. If all of the Antarctic ice were to melt off -- an extraordinarily unlikely event, fortunately -- sea levels would go up by 60 meters.
We live in a post-Katrina world. We have graphic evidence of what it looks like to have a city nearly destroyed by the weather. Even people safe in regions distant from the oceans now know what kind of damage losing just one major city can do to a nation; imagine what damage to every major coastal city would do.
If notions of climate refugees, spreading diseases, and higher insurance prices won't make people act, maybe the thought of seven meters will.
(Thanks for the tip, Adam Burke)
