The charity Practical Action has hit upon an interesting way of demonstrating how a rise in ocean levels would impact on London: they've created an alternative Tube map which shows the areas of the capital that would be flooded.
Bad news if you live in Docklands, Greenwich, or pretty much any riverside burg between Canary Wharf and Kew: you're unlikely to escape the flooding. Much of the Thames Embankment, including the Houses of Parliament, would also be hit. Barking, which isn't particularly near the Thames but does have a creek running near it, would also be flooded, while City Airport would also perish. If that doesn't make you turn your thermostat down by one degree, then nothing will.
For more on the Thames flood plain, see Diamond Geezer's list of endangered places from last year.