By Rose Eveleth
Posting in Cities
We always hear about island nations suffering from sea level rise. But the risks are real in the United States as well. A new project maps those risks.
Yesterday, the New York Times published an in depth look at sea level rise in the United States. The story is a collaboration with Climate Central, a nonprofit news organization who collected and mapped sea level data for areas all over the country. Their interactive map is here.
The New York Times wrote:
The project on sea level rise led by Dr. Strauss for the nonprofit organization Climate Central appears to be the most elaborate effort in decades to estimate the proportion of the national population at risk from the rising sea. The papers are scheduled for publication on Wednesday by the journal Environmental Research Letters. The work is based on the 2010 census and on improved estimates, compiled by federal agencies, of the land elevation near coastlines and of tidal levels throughout the country.
Users can look up their zipcodes on the map to see what their risks are. Many places have a one in six chance of experiencing a foot of sea level rise by 2020. That might not seem like a lot, but even a few inches of rise can erode the soil and cause big problems. And there are 3.7 million people in the lower 48 states living within one meter of the coast. That’s over one percent of the nation’s population.
Some places are doing things to prepare. New York City has raised their pumps at sewage stations so that they don’t get inundated with the rising water. But most places haven’t really done much.
Image Credit: Flickr, go_greener_oz
Mar 15, 2012
According to the best estimates sea level is rising 2mm per year - that's less than 10 inches per century. Sea level may be rising, but really how good are those estimates? There is actually a huge credibility gap in our ability to measure 2 mm per year changes in sea level - when terrestrial tides can change the earths surface 55 mm in some places every 12 hours. Now consider that those changes are not necessarily predictable because of changes in earths crust rebound characteristics, magma flows beneath and magnetic field changes - which make the changes in the earths crust rather erratic on a 2 mm scale. You might also remember that our GPS satellite technology with this kind of precision is a relatively new ability - so scientist have next to no historic measurements with this kind of accuracy to compare their current measurements. Computers can only give answers as accurate as the information they receive. Ahhh, the power of money in the form of big gov. and NGO grants to shape scientific "facts." http://en.wikipedia.org/wiki/Earth_tide
In case anybody thinks the sea level rise is all due to global warming, the fine print on the map says that it shows where "local sea level rise projections were combined with storm surge and tidal statistics to estimate the decade by when there is an at least 1 in 6 chance of different water levels occurring, at least once." (see http://sealevel.climatecentral.org/maps/about-surging-seas-map/ ). This is a pretty low bar, and storm surge will be much more of a factor than increases from global warming. Of course, nobody really knows how much global warming will cause the sea level to rise in the future, nor the strength of future storms. It's all a computer model somewhere. Ms. Eveleth does the Smartplanet community a disservice by not pointing out these facts behind the study in her article.
So WOW! It looks like that Disney timeshare I purchased in Florida will become waterfront property in 100 years! What a great investment I made!
First, the idea that "money in the form of big gov. and NGO grants" is driving science is a little naive, when you compare the amount of research money from the oil and automotive lobbies. Your point seems to be that the sun and the moon influence the Earth's geoid on a periodic basis, which is undoubtedly true. However, these variations in the Geoid can be calculated very accurately with nothing more than classical mechanics. I suggest you do some googling. Next you claim that sea level rises have been of the order of a few mm per year. This was probably true throughout the 20th C, and if sea level changes could only be measured annually then this would be a difficult trend to spot. However, if you measure sea levels every 25 years then 2mm annual changes combine to make a 50mm (or 2 inch) change, which is easily detectable without satellite data. However, the 2mm per annum figure was for the 20th C. For the 21st C, the predicted ocean rise is predicted to be between 2-7 feet with 3 feet the most popular value. (The exact result depends on the IPCC scenario, which depends on factors like AGW responses, discontinuous collapses in the Gulf Stream and other unknowns.) A value of 3 feet per century equates to about 10mm per annum, which can be (and has been) measured with satellite technology for some time. The IPCC reports the best available predictions for a range of scenarios. Even if you choose the rosiest scenario (in which it's assumed that everyone cuts their greenhouse emissions, the atmospheric physics unknowns are horribly wrong, etc.) the predicted warming and sea level increases are still worrying. Indeed, the rosiest IPCC scenarios just suggest that we have more time to correct Global Warming - not that GW is not a problem.
Portland ME- - Over 1 in 6 chance sea level rise + storm surge + tide will overtop - I can tell you on any given day for the last 40 years a storm surge has a better than 1 in 6 chance of coming over the average New England seawall. The storms are called Northeasters for a reason. Storms frequently get up into the Gulf of Maine and sit there pounding a northeast wind into the coast. Combine that with a lunar high tide and a big storm surge is coming.