The horrible flooding in Manhattan last month, documented in this amazing photos from Twitter, could become a regular thing.
A cool series of interactive maps from the NYT, showing where sea levels may be for major American coastal cities in the next several hundreds years. (The title quote is from an opinion piece that doesn’t really explain much, the maps are more interesting.)
These maps are based on elevation data from the U.S. Geological Survey and tidal level data from the National Oceanic and Atmospheric Administration. Maps show the extent of potential flooding relative to local high tide.
The 25-foot sea level rise is based on a 2012 study in the journal Science, which augmented findings from a 2009 Nature study. They found that 125,000 years ago — a period that may have been warmer than today but cooler than what scientists expect later this century without sharp pollution cuts — the seas were about 20 to 30 feet higher than today. If temperatures climb as expected in this century, scientists believe it would take centuries for seas to rise 20 to 30 feet as a result, because ice sheet decay responds slowly to warming.
The maps show that by the year 2300, even with moderate cuts in pollution, the following cities will be flooded to the percentage noted next to them:
- Baltimore 5%
- Boston 24%, Cambridge 51%
- Charleston 42%
- Houston 1%, Galveston 97%
- LA 2%, Long Beach 20%, Sacramento 27%, SF 11%
- Long Island 12%
- Miami Beach 100%, Miami 73%
- New Orleans 98%
- New York City 22%
- Atlantic City 97%
- Philly 6%
- Norfolk 78%
- DC 7%
And here are the maps just for NYC over the next 300+ years, but there are a number of other cities to check out, including Washington, DC, Seattle, San Diego, Philly, New Orleans, Miami, Houston, LA, Boston. It’s kind of cool, in a terrifically frightening disaster movie kind of way. The light blue is previously above-water land that has become submerged.
A bit more on the problem of rising sea levels, from National Geographic – their numbers seem to parallel the ones the Times is using:
Most predictions say the warming of the planet will continue and likely will accelerate. Oceans will likely continue to rise as well, but predicting the amount is an inexact science. A recent study says we can expect the oceans to rise between 2.5 and 6.5 feet (0.8 and 2 meters) by 2100, enough to swamp many of the cities along the U.S. East Coast. More dire estimates, including a complete meltdown of the Greenland ice sheet, push sea level rise to 23 feet (7 meters), enough to submerge London and Los Angeles.
And more from CBS:
New York City’s Office of Emergency Management predicts sea levels two to five inches higher in the next decade; seven to 12 inches higher by the 2050’s; and up to nearly 2 feet higher by the 2080s.
And more from the Washington Post on what can be done, and why even small improvements can help:
We’re going to need to adapt to sea-level rise no matter what we do on carbon emissions. Even the “optimistic” scenario in the NCAR paper still envisions sea-levels rising roughly 11 inches by 2100. That’s assuming we cut emissions drastically and the ice sheets don’t do anything too unpredictable. Even then, New York City will have a bigger flood zone than it does today. Storm surges on the coasts will be much larger. Low-lying areas will be at greater risk. In Bangladesh, for instance, the area prone to severe flooding would increase by 69 percent (pdf) with just a foot of sea-level rise.
That said, cutting emissions can make a significant difference this century. Keeping sea-level rise a foot or two lower than it otherwise might be is nothing to sneeze at. As this map of New York City shows, the flood zone increases dramatically with each additional foot of sea-level rise. A city like Norfolk, Va. could get swamped entirely by a Category 3 hurricane if ocean levels rose by two to five feet. Florida’s adaptation costs go up by billions of dollars with each additional foot of sea-level rise. Every little bit helps.