When Sea Levels Attack

Monday, February 22nd, 2010

It’s difficult to keep track of all this shifting information on sea level rises.

It doesn’t help that in climate change reporting, a consistent but bewildering assumption is repeatedly made: that we understand what a 1 metre sea level rise actually means.

A “1 metre sea level rise” is in the same domain as “1 ton of carbon” or “£1 billion”. That is, it’s meaningless without context or some link to our everyday lives.

So, in this latest diagram for The Guardian Datablog, I’ve tried to sum up all the current research on sea level rises. What will happen, when it will happen, and where all that sea water will come from. And to suggest what cities will flood When Sea Levels Attack!


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  • Ian Lee

    Beautiful as always. Great job. I’m just curious about New Orleans. It’s my understanding that they’re basically under water already if it weren’t for the levies. Does this represent the breaking point of all man-made water deterents or just simply the current elevation of the cities?

  • Tamsin Edwards


    I always like your attempts to visualise numerical information but this is the second time I have been disappointed by the accuracy (after The Billion Dollar Gram). Did you get any sea level rise scientists to check your figure? I’m a climate scientist just getting into the area of sea level rise.

    At the very least: West Arctic -> West Antarctic; this is then double-counted in the Antarctic total. Also: 1m per century due to thermal expansion on the axis, while seemingly 1-2m on the graph.


    [Thanks for the correction! David]

  • Jason R

    No, no, this is all wrong. Clearly just another attempt to deny global draining. ;)

  • Mac

    Edinburgh is 41 metres above sea level.

    That is a serious error.

    [Apols limitation of the diagram - Edinburgh would be "water logged" with a 6m rise:

    "The Benfield team has predicted that a 20ft rise would leave many towns and cities, including Edinburgh, Newcastle, Bristol, Plymouth, Norwich, Peterborough and Bournemouth, waterlogged, with well over two million people displaced." - Thanks! David]

  • Mac
  • Nick

    Information is Beautiful? Information is wrong! What is the ‘west arctic ice sheet’? I’m no expert, but surely that should be ‘west antarctic’? Get yr fact checkers all over this graphic please before it becomes Informationisbeautifulgate and an excuse for deniers to claim another global media conspiracy .

  • Mac

    The inability to correct the graphic means that you are misinforming people.

    You must remember that information can be ugly as well.

    “Science is organised common sense where many a beautiful theory was killed by an ugly fact.” Thomas Henry Huxley

    [Apols Mac. The graphics is not meant to suggest that Edinburgh will literally be submerged by water. Only that it will be prone to flooding When Sea Levels Attack!]

  • Lyle

    The graphic for this is in error for Los Angles and San Francisco unless you mean that any part of the city could be flooded, but then the answer for any port city would be in the 2-3 m range. For LA the city hall is around 100 m (20 some miles inland), for San Francisco it varies but city hall is at around 15 m in elevation. So in both cases parts of the city would flood but not most. But as the grapic is done then any port city is subject to flooding at the 2-3 m level as that would flood the warves.

  • Sym

    I saw a rather nice way of presenting this on a google map a few years ago:

  • ScruffyDan

    I wish to echo some of the criticisms left by other commenter, though hopefully more politely.

    I used your image for a blog post I wrote on my site (I linked back to the Guardian piece on it, hope that is ok), and got some comments from people who I generally trust on issues such as this, that while the graphic is generally good there are some issues that need to be fixed or clarified.

    New Orleans in particular seems misplaced, being able to survive sea level rise of 6m. Same thing goes fro Shanghai.

    And there is some confusion as to how you deal with cities that have large ranges in elevation (LA and SF).

    Also the complete melt map (upper right) shows more inundation than an 80 meter rise would indicate.

    The post and comments regarding the graphic is here:

    Perhaps we are just misinterpreting your work, or your methods?


  • Patrick

    Great graphic, but experience of Edinburgh means I have to agree – whatever sources used to indicate that indicate would be flooded or waterlogged or whatever at 6m rise ned to be more specific.

    The Port of Leith is at sea-level, more or less; but most of Edinburgh is way above. The city centre is way more than 6m above sea level – it is a long walk up the hill to Princes St!

    Central London would be underwater way before Edinburgh.

  • social bookmarking

    The impacts of sea level rise – even in the lower ranges of the current predictions – looks to be severe. Approximately ten percent of the worlds population – 600 million people – live in low lying areas in danger of being flooded.

  • Bill Roberts

    It’s a nice graphic, but putting aside the various points above about the topography of different cities, I think it misses one of the most important aspects of the risk of sea level rise. The sea level goes up and down all the time due to tidal and weather conditions. The biggest concern about rising mean sea level is that it will increase the frequency of extreme high water events, so that the risk of a damaging flood becomes much greater. Flood defences designed to protect against a one in a thousand year event become vulnerable to (say) a one in ten year event.

    Illustrating this increases the challenges of designing a great graphic of course! But it would be interesting to try to bring in that element of risk or frequency.

  • Veester

    You should look at this if you want to review sea levels….

    great bit of research

  • bookmarking service

    when we had a devastating tsunami around 5years back, the amount of sea level changes took place was just infinite. in most of the areas sea and beaches went back and gave space to more land

  • orlando taxi

    Illustrating this increases the challenges of designing a great graphic of course!

  • submitshop

    Nice Blog. Thanks for sharing this nice information
    You must remember that information can be ugly as well.


  • removalist sydney

    yeah the grean house effect is coming into action i guess, so is all this stuff of rise in sea water level.

  • Milano

    Yes it’s a nice graphic but not so beautiful information.
    I remember the film “An Inconvenient Truth.


  • Scene Clothing

    OMG that is so scary! I’m just wondering now what will happen to all the electronics that are meant to help us surivive. Won’t they just break when they contact water??

  • Blye 123

    That is really scary to think that over time cities are going to go under. But we could try to stop global warming so it doesn’t happen. The truth scares me!!!!!!