My sea level rise paper from RSNZ

This is what I’ve been putting together for the last few months.

Royal Society of New Zealand paper highlights new research around sea level rise

Summary: In 2007 the IPCC said 0.2-0.6 metres by end of the century, but maybe more coz ice sheets are melting and we don’t know how much that melting might increase. In 2010, we can say that the ice sheets are melting faster, we’ve some idea about how fast they might melt, but we’re still not sure, so 0.5 to 1.5 metres looks like something we should plan for.

12 thoughts on “My sea level rise paper from RSNZ”

    1. Thanks, I typesetted it all myself.

      (Actually, I tried to squeeze more content into this one than I should have, so some of the font sizes are too small for the print version. Ah well, you live and learn.)

    1. You no can has.

      Areas of flooding can be misleading. What we really need to know is what will be built on low-lying areas in several decades time. Or, if we’re talking about long-lived infrastructure, what will be built that will still be standing and needing to be used in a few hundred years time.

      I wanted to include some dollar estimates of financial impact. There are none, for New Zealand, right now. (Well, none that are credible, I’m sure some people have pulled numbers out of the air.)

      There’s lots of argument about how best to present the limited info that we’ve got. You can find flooding maps for several NZ cities, but their value isn’t great, right now. More research is needed (and is underway).

    1. And here’s some other pretty pics:
      Firetree
      Sea Level Rise Explorer

      So yeah, not much change in Wellington from +1 metre.

      Maps where you just take the height and say everything under that height will get wet are called bathtub models. They result in pretty pictures and a guide to what might happen, but coastal hazards people get very un-nerved when people just look at pretty, but potentially misleading pictures. They can be misleading because of the data, the impacts, and the vulnerabilities.

      Data really needs decent resolution, which means better than 1 m in height, and in cities, you need to be able to discriminate between the heights of the ground level versus the heights of the tops of buildings. This is often hard, and LIDAR data of cities is expensive.

      The impacts depend upon the kind of coastline, but also on what we’ve built there. Wellington CBD won’t get washed away, we can afford a decent sea wall. However, the problem for Wellington is less big waves and more flooding when heavy rains find it hard to drain into a sea that’s higher than it used to be.

      And the vulnerabilities are hard to show on maps. It depends as much on what buildings are built were as it does on how those buildings are built. If buildings are relocatable, then it really doesn’t matter if they are on land that will be under water in fifty years time.

      1. Indeed. I know it’s not very informative on it’s own.

        Rainfall/hydrological modelling seemed pretty mature when I was investigating general GIS-based models, so they’d probably help with predicting the areas at risk from flooding.

        Financial impacts is something the weed/invasive species modelers want to know about too, but it does seem somewhat of a black art… particularly when you’re trying to value ecological habitat.

        1. Yeah, putting a value on buildings (that might not have even been built yet) is easy stuff compared with valuing eco-systems. That’s just ludicrous, banging head on wall stuff.

          Hey, guess what project I’m going to be working on in two projects time?

  1. As someone once said “There’s Lies, there’s Damn Lies, and there’s Statistics”

    The Name Benjamin Disraeli springs to mind, but I don’t trust my aging brain cells, and I’m can’t be bothered looking it up…

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