In the news today, NASA adds weight to the common — but curiously inert — conclusion that ice sheets are melting and seas will be rising. One thing I’ve not seen much of is actual adaption strategies to this. Of course in the longer term it remains to be shown that there is any possible adaption which will avoid human extinction or reduction to a form of subsistence economy which makes the concept of adaption moot. We can hope.

In the short to medium term, though, say we are looking at a 4–5m rise in average sea levels. The timescale for this may be a hundred or two hundred years (the viability of current models for this is questionable; new points keep coming along to make it worse). I’m particularly thinking about the impact this will have on the town nearest to me. Much of the existing commercial centre will at some point be under water at normal high tides (rather than parts of it, every few years, at some high tides with a heavy swell). How can adaption work? Arguably there could be viable approaches which retain the existing town footprint — flood barriers are popular in some places, but I have doubts about it in this case; spending that amount of money for very small populations may not be an option. So perhaps a more sensible approach is to require all new buildings or refurbishments to take sea levels into account over their intended lifespan. (Though buildings are often used beyond their expected lifespan, especially during prolonged economic downturns.) At this point, if a given piece of work is only intended to last a decade, probably there is no new requirement. If fifty years, well, maybe occasional protection against higher storm surges than we’re used to for all but the lowest-lying or most exposed. Beyond that, we probably need to think bigger.

The commercial centre I refer to is about 2–4 metres above MHWS. We can expect that with 4m extra, practically the whole of it will become a tidal zone. Could this be handled by adapting the existing space? It’s an intriguing thought that you could have, here and elsewhere, a sort of tidal Venice, with walkable streets at low water, and pedestrians retreating to raised pavements and bridges at high water. In some settings that might work very well. However, this is Scotland (cold, windy), and the town is at the end of a deep sheltered bay (silty rather than sandy). Manageable? Maybe. It would work better where you have more open, cleaner, water and warm sandy beaches encroaching on you.

Still, if the next generation or two of architects get a grip and start designing for adaption, it may be that the ground floors can be built to be either sealable with minimal work, or let flood, while the first floors become the main entrance from the raised pavements. In effect, the coastal parts of the town need to move up a storey or two. Serendipitously, when the existing first floors have become the ground floors, the existing ground floor can be the sea-floor.

But maybe that will just be too big a project. Taller jetties may be easy enough, and walkways from the new to the old shoreline, but chances are most existing buildings — in this particular case essentially all the town centre shops, pubs, hotels and library — will be too expensive to keep up or replace. The whole town will need to move inland. This actually makes more sense, because unless we discover something really new in the way of carbon handling, we have no obvious prospect of the sea stopping at 4–5m, and every prospect of the rate of rise increasing past the point where it makes sense to try to adapt the existing town. A move inland by miles, and up by some tens of metres is more likely to be needed.

I could largely shrug this off, as I already live at about 50m, and am unlikely to live to see even 1m rise. But that’s not an excuse. Thousands round here currently live under 10m, and many millions around the world. But, it’s true that I can’t decide on the detail of the adaption required for everyone. I can hope it’s possible. I can’t persuade myself that’s sufficient.

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