Here comes the flood

News today of interesting new research on the effect of rising sea levels on 180 US coastal cities by the century’s end. University of Arizona scientists will be publishing a paper this week in Climatic Change Letters which sees an average 9 per cent of the land within those cities threatened by 2100. The Gulf and southern Atlantic cities, Miami, New Orleans, Tampa, Fla., and Virginia Beach, Va. will be particularly hard hit, losing more than 10 per cent of their land area.

The research is the first analysis of vulnerability to sea-level rise that includes every U.S. coastal city in the contiguous states with a population of 50,000 or more. It takes the latest projections that the sea will rise by about 1 metre by the end of the century at current rates of greenhouse gas emissions and thereafter by a further metre per century.  The researchers examined how much land area could be affected by 1 to 6 metres of sea level rise.   At 3 metres, on average more than 20 per cent of land in those cities could be affected. Nine large cities, including Boston and New York, would have more than 10 per cent of their current land area threatened. By 6 metres about one-third of the land area in U.S. coastal cities could be affected.


The study has created digital maps to delineate the areas that could be affected at the various levels. The maps include all pieces of land that have a connection to the sea and exclude low-elevation areas that have no such connection. Rising seas do not just affect seafront property – water moves inland along channels, creeks, inlets and adjacent low-lying areas.

“Our work should help people plan with more certainty and to make decisions about what level of sea-level rise, and by implication, what level of global warming, is acceptable to their communities and neighbours,” said one of the co-authors.

An interesting notion, that of deciding how much sea level rise is acceptable. Shades of King Canute? It’s presumably the speaker’s way of pointing out that it may still be within our power to keep it manageable if we begin an urgent and drastic reduction of greenhouse gas emissions. Or perhaps he’s hinting at a time where only relocation will serve. For the present some adaptation measures are now unavoidable and should be planned for, but hopefully the digital maps of this study will help convince people that mitigation is also essential. Not seemingly the Republican majority in the House which bizarrely rampages on as if human-caused climate change isn’t happening, let alone in need of mitigation.

I wonder how much similar mapping has been done in the case of New Zealand coastal cities. The Wellington City Council has gone so far as to consider a computer-generated graphic (pictured) which visualised the effect of a one metre rise in sea level on the city. Nelson has considered a commissioned report on climate change effects which warned that a 1 metre sea level rise would have water lapping at the airport. I don’t recall seeing anything which indicates that Auckland has seriously looked at the effect. Christchurch is planning for a 50 cm sea level rise this century with the recognition that it may be higher and presumably that means they are undertaking detailed consideration of vulnerable areas. Dunedin has had the benefit of some University of Otago modelling of a 1.5 metre sea level rise, reported here, with assurance from the new Carisbrook stadium that they’re 3.7 metres above mean sea level.   I’ve written earlier on encouraging signs that local body government in New Zealand, at least in some areas, is facing up to the responsibilities for adaptation. In some cases this has meant taking on mitigation measures as an obvious consequence, though Environment Waikato’s Proposed Regional Policy Statement states that the Council’s role is to prepare for and adapt to the coming changes and that response in terms of actions to reduce climate change is primarily a central government rather than a local government role. I’ll be challenging that in my submission, since it seems to me that engaging people locally in mitigation effort is both possible and sensible, especially when they can see locally what the prospects will likely be without it.

The costs of coping with sea level rise look likely to be enormous. If in fact that is what future populations have to do they will look back in wonderment on the argument represented by such as  our present government that we were unable to do anything deeply serious about mitigating the effects of climate change because we thought it might affect our economy adversely. True, we might have to acknowledge, there was a Stern review which pointed out that the costs facing you, our descendants, would dwarf the adjustments required of us, but somehow we couldn’t get over our hump to reduce your mountain.

[Peter Gabriel]

25 thoughts on “Here comes the flood”

  1. The interesting thing here is the focus is on rich western nations low lying land and cities. Most of the focus is usually on small Pacific islands and Bangladesh which are far away distant lands and we can send $10 to Oxfam. The San Fernando Valley is source of food and fresh water to millions of city dwellers and is very vulnerable,
    Articles like this sharpen the mind of more people to the realities of global Warming.

  2. “I don’t recall seeing anything which indicates that Auckland has seriously looked at the effect. ”

    I scanned closely what I could find of the plan to raise part of the northwestern motorway which even now gets flooded but could find no reference in public notices to sea level change or any indication of height above high water.

    Nor in studies of the effect of sealevel rise have I ever seen reference to the concatenation of extremes which even now can be a serious matter. Take Auckland: king tide plus depression raising water level plus nor-easterly building up water in the Hauraki gulf plus local flooding in heavy rains such as occured very recently to the eastern suburbs. Add a bit of stormsurge if tropical depressions target Auckland instead of skipping past as they usually do.

    Hence when people shelve the issue with the thought that such a slow sea-level rise as 3 or 4 mm per year is not going to bother anyone soon I always ask them to consider the extremes with the additional facts of measured rise in water vapour with temperature and increase in frequency of extreme weather events.

    1. Exactly. Due to the daily rhythm of the tides and variations due to king tides the effects of sea level rise will at first be felt during king tides combined with storm surges as in the event we recently had. People will be deluded easily in putting sea level rise out of their mind in the meanwhile. However just as as with the rising frequency of severe flooding it will be the rising frequency of local coastal flooding that will render areas unable to attract further flood insurance and therefore void for economic development or building activity. It will be the insurance companies reactions much more than the proverbial tide gauges that will foretell the future of things to come…..
      The free market realists in the insurance offices will tell their climate change denying free market peers where not to put their money….. where their mouth is!

      How about we open a climate change skeptics insurance company that renders cover to GW flood risk prone areas with the money invested from deniers. If they were so sure about their prognosis then by golly they would find rich pickings insuring those that the rest of the industry won’t touch!

      1. What a great idea! Take a crushing burden off the mainstream economy, and they could still offer very reasonable premiums, because they just know (and that’s about all there is to it, really) nothing’s going to happen! Money for nothing!

        Of course, finding stupid actuaries might be a bit more difficult…

        I also like the phrase ‘market realists’. As opposed to their ideological counterparts. This gets to some of what I was referring to in an earlier comment on the Chomsky post – there’s plenty of sane capitalists who are not caught in an institutional bind that requires them to be stupid! These people are our allies in this…

  3. Regional councils are required by the NZ Coastal Policy Statement to take a 100 year view of things. See policy 24:

    I think they do pretty well in responding rationally to expert advice – as opposed to central government. I think the extra discipline on councils is that they can get sued if they allow people to build in vulnerable areas. Eg on poor soils in Christchurch.

    NIWA has told councils to anticipate up to 1.8 metres sea level rise by 2100.

    I see two problems though. First, the true effects of 1.8 metres are in no way anticipated in these images that show a calm lake gently flooding the inner city. The Wellington example you cite talks about the inner city becoming like Venice. That is nonsense of course. If you take into account things like normal wave action and also “cumulative effects of sea level rise, storm surge and wave height under storm conditions” (as coastal policy requires) Wellington will either be a walled or massively reclaimed city or the inner city will be abandoned. Expect your rates to rise either way.

    Second, the NZ predictions and current council policy rest on key papers such as the one by Pfeffer and others in 2008 that argue that physical restraints on Greenland mean that sea level rise of more than 2 metres this century is “physically untenable”. James Hansen and Makiko Sato beg to differ. The foresee as much as 5 metres. Worse, it creeps up and then goes exponential. So you would notice say 300mm rise by 2040 and then it gets to 5 metres by 2100 and keeps climbing. See fig 7 in their paper:

    So this may create an interesting legal moment. What should councils do about coastal development proposals now if they dont want to get sued by irate ratepayers in the future?

    BTW I think Thomas’s idea of a skeptics insurance company is brilliant. All it needs is a large bank stupid enough to underwrite the insurance policies …

    1. Tom, I hadn’t caught up on the NIWA advice to anticipate 1.8 metres sea level rise by the end of the century. It’s nearly a couple of years since I wrote about the Ministry for the Environment’s guide to local government on preparing for climate change where the advice was to take a 0.5 metre base line, but to consider the consequences of a rise of at least 0.8 m. That leaves the way open for a higher rise, but is the 1.8 m figure you mention set down somewhere?

    2. The idea of this insurance fund would be to have the skeptics fund and underwrite this insurance themselves, not a bank with the savings of unsuspecting account holders.

      Surely the good old Viscount Monckton would be willing to start the fund up with a guarantee against his assets.
      I can see among the funds trustees Senator Inhofe and as scientific advisers such luminaries as De Freitas, Lindzen, Michaels et. al.
      Perhaps they could ask Koch Industries to join the underwriters. Surely they would be delighted to be asked…..
      I think this whole idea really has merit. Then you could ask all these vocal deniers to take out shares in that insurance company to publicly prove that they actually believe what they say.

  4. Ouch. My bad. You are correct. Its 0.8m not 1.8m. By way of example, for the Overseas Passenger Terminal redevelopment in Wellington the applicants have worked on the basis of 0.8 metres. They relied on Pfeffer’s conclusion that:

    “We find that a total sea-level rise of about 2 meters by 2100 could occur under physically possible glaciological conditions but only if all variables are quickly accelerated to extremely high limits. More plausible but still accelerated conditions lead to total sea-level rise by 2100 of about 0.8 meters.”

    The NIWA guidance manual 2008 says:

    “At the very least, all assessments should consider the consequences of a mean sea-level rise of at least 0.8 m relative to the 1980-1999 average.”

    1. Oh my golly. This is really so darn stupid. I guess after they gain control in 2012 they will simply outlaw global warming…. 😉 done and dusted….

      And there is history to all that… in 1897 the Indiana House of Representatives decided that they would redefine the value of Pi to be something simpler than the usual pi = 3.14159265….

      see here:

  5. Thanks for the link sailrick. I hadn’t seen it all gathered so tellingly before. I paused slightly before writing bizarre rampage in my post, but the words look positively restrained in the light of the Hill Heat list

  6. Can you imagine what the world is going to be like if this army of angry idiots gets control of the Whitehouse in 2012?

    The environmental movement in the US has a long association with the Republicans, for crying out loud, going back to Theodore Roosevelt, and the EPA was Nixon’s! Even EarthFirst!’s Dave Foreman was a Republican –

    “You dirty communist bastard! Why don’t you go back to Russia!” screamed Les Moore, the heavy-equipment operator who tried to
    run Foreman over in 1983.

    “But, Les,” Foreman replied, “I’m a registered Republican.”

    I agree that the GOP appears to have been taken over by loons, a process critically accelerated by the manipulated pseudo-populism of the various Tea Party factions. Even the term ‘epistemic closure‘ – which well describes the mindset behind such systematic paranoiac perversity – is an internal critique arising from the (sadly shrinking) fraction of realists within their own party.

    Between the strident loons on the Right and the mealy-mouthed, compromised and cowardly hypocrites on the ‘Left’ (or, let’s face it, the not-quite-so-Right) the mighty USA seems to be digging itself further into the mire every day… it would be nice to have it back in the real world but I don’t hold out a lot of hope.

    There’s a lot of great thinkers there, as always, but they’re being held captive at the back of the bus, howled down by the bug-eyed brigade any time they dare mention, you know, that cliff? the one right in front of us?!…

    1. TROPICAL Cyclone Carlos has dumped more rain on Darwin in the past 24 hour than Cyclone Yasi inflicted on any town in a single day.

      Weather Channel senior meteorologist Dick Whitaker said Darwin recorded a total of 339.6mm of rain during the last 24 hours, the NT News reports.

      This is an all-time, 24-hour rainfall record for the city,” he said.

      Wow, an all time record for the capital city of The Wet!

      Steve; if you’re lurking – that’s not not-unprecedented. Again. And I challenge you to find anything even close to a precedent for the cluster of flooding events across Australia – even dry old SA! – since the beginning of 2010.

      And since you’ll probably only complain about Australia’s short recorded history, does breaking a record going back to 1766 impress you more?

      But wait – that was in 2000! So, let’s guess, in the UK AGW driven extreme rainfall peaked 10 years ago?

      1. And it’s **still** raining in Adelaide. I suppose the festival organisers are trying to work out whether this is better or worse than the heatwave a couple of years ago.

    2. Bunch of rubbish from Nature in your link quokka. How many mays, ifs and coulds are there? I like this ‘scientific’ statement…….
      “We can now say with some confidence that the increased rainfall intensity in the latter half of the twentieth century cannot be explained by our estimates of internal climate variability,”
      What increased rainfall ‘intensity’? What does ‘some confidence’ mean?What are ‘our estimates’?

      Lets look at what this means …. more food to feed the hungry! …. now… “India, the world’s second biggest wheat producer after China, is heading towards harvesting a record 81.47 million tonnes of the produce in the 2010-11 crop year” …. this is NOT what Pachauri said would happen a few years ago.
      …in 2007….Climate change is bringing down wheat production in India, chairman of the Intergovernmental Panel on Climate Change (IPCC) Rajendra K. Pachauri said… “Agriculture productivity, particularly of wheat, has shown signs of going down as a result of the climate change,…”
      Just who are we to believe? – certainly not political alarmist scaremongers like the IPCC.

      1. Sceptic Lank,

        You must truly have a remarkable intellect to have read and fully understood these papers in such a short time, or (and far more likely) you have not read the papers and are just shooting your mouth off.

        1. Thank you for the compliment quokka but it does not take a ‘remarkable intellect’ to see through this rubbish. It is not a scientific study, more a work of fiction aimed to feed an alarmist agenda.

  7. first: Bryan thank you for Peter Gabriel – had forgotten all about that song.

    All: regarding Republicans – yes, scary. Check out this great Esquire magazine article “Greetings from Idiot America.” sums it up nicely – very well written.

    Finally, check out Mark Hertsgaard (author of new book called Hot which I’m sure you’ll review at some stage Bryan) – fabulous comment on the GOP… it took the church 379 years to accept Galileo’s theory that the earth moves around the sun – how long will it take the Republicans to accept the climate science?

    (this post may appear twice – a glitch deleted it)

    1. Cindy, I can’t take credit for the song choice – that’s Gareth’s, along with the title. I just do the words in between. And yes, I have asked for a copy of Hot and will be reviewing it in due course.

  8. Sceptic Lank : How is Dr Pauchouri’s “has shown signs of going down” any less equivocal than the language (“ifs and buts”) that you object to in the Nature paper’s conclusions? In the latter case you claim not to know what it can mean, but in the former you absolutely know that Dr Pachauri meant there would never be another good harvest in India. Which you’ve heard there will be.

    It’s good news for buyers in that market that the Indian harvest is being talked up.

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