Sea Level Rise

As you fly out of Manila airport, as I did yesterday (greetings from Singapore!), you are sure to be struck at the size of the metropolitan area. The metropolitan region covers 247 square miles and is home to 22 million people. The city proper has 1.65 million inhabitants and Wikipedia says it is the most densely populated city in the world.

What struck me is how flat it is. The average height above sea level appears to be about six inches (although that is surely an exaggeration brought on by a birds-eye view). In fact, other parts of the infallible internet inform me that the average height above sea level is 13 feet. But the conurbation begins at water’s edge and it doesn’t start rising until long after downtown has been passed.

When we fight about sea level rise in climate change conversations, most of the time we orient the discussion around its potential effects on developed cities–that’s where all the big money is invested and where the insurance coverage is most complete.


But this city is vulnerable to sea level rise and changed precipitation in a way that rich world cities are not. Because many poor people live in Manila, it hasn’t developed the infrastructure capacity to give it resilience against either event. They have suffered from historical flooding without any help from climate change. A tropical storm as savagely targeted as Sandy in the U.S. could kill tens of thousands and leave millions homeless.

This is one place where the observed average sea level rise of 3 millimeters per year–something that seems laughably inconsequential for the developed world–is actually a real threat to human life.

So while I still feel that actors on the climate stage are exhibiting infantile or criminal behavior, this issue stays alive for me. And to connect it to recent events, I would much rather see Gleick, Lewandowsky, Mann and others of their kidney retire and take up knitting, I am sorry to see James Hansen retire from NASA. He is foregoing a role that gave him a bully pulpit in favor of a more personally satisfying, but far less effective role as an activist.

Any fool can get arrested. It takes a career to get to a position where you can influence public policy. Adopting the first at the expense of the latter is a sad turn of events for both science and politics.

40 responses to “Sea Level Rise

  1. Thank you for another well-written thought essay. It is what keeps bringing me back to your blogs.

    Here is an interesting take on sea-level rise. I live in Southern Minnesota, not far from the Iowa border. Here the soils are black and the terrain flat. Perfect farm country. Unlike elsewhere in the country, our problem is too much water, not too little.

    In the spring and late fall it is common to see trucks passing by on our county road, carrying large coils of plastic field drain tile to feed the tiling machines. Around here ditch wars are fought out in the bars and courtrooms as farmers struggle for the right to get rid of water.

    But this year, coming off a drought and with the high price of corn, everyone is installing irrigation systems. They are not doing this because of “climate change” rather they are flush with cash from a bumper crop and looking for ways to eek out another 20 bushels of corn per acre in the inevitable dry years.

    So what does this have to do with sea-level rise and Manilla?

    Where does all that water go? Well, the drainage water goes into the Cedar River and down the Mississippi into the sea. The water from the tapped aquifer will go into the atmosphere and eventually into the sea.

    Our aquifer will recharge but once you tap it there will always be a temporary net loss between outflow and inflow and that has to be accounted for.

    Out west, farmers are draining the Oglala aquifer and pumping it into the air. That water will take another glacial age to recharge. Amazingly, climatologists tell us our climate is becoming wetter. These guys never put two and two together.

    I found this article in Nature that attributes a sea level rise of three-quarters of a millimeter a year to aquifer depletion. See Source found for missing water in sea-level rise

    We have drained much of the Aral Sea, much of the Oglala aquifer and other larger aquifers in Russia and Pakistan…. but that is just part of the story. We have also dimpled the aquifers under our farm and city wells and all of that adds up.

    Granted we have also created some large reservoirs, but we have put more water into the sea than we have held back.

  2. Americans have the knack of encapsulating complicated concepts in very few words. I like the term “bully pulpit.” It expresses perfectly all the tropes, memes, history and idioms connected to the appeal to false authority.

  3. “I am sorry to see James Hansen retire from NASA. He is foregoing a role that gave him a bully pulpit in favor of a more personally satisfying, but far less effective role as an activist.”
    At NASA, Hansen has a bully pulpit to talk science. Outside of NASA, he has pulpit to talk about what to do with the information science provides.
    He is doing that, and as Keith Kloor notes, the media – especially environmental reporters – are ignoring him.
    The climate concerned shout “Manila is threatened today!” without talking realistically about what to do about it. If Manila is threatened, building a windmill in New York and protesting Keystone isn’t going to do a damn thing about it. We have to replace coal with something that works and leaves enough money on the table to prepare for flooding (which will happen in Manila with or without AGW).
    I couldn’t care less what excuse is used to transition to nuclear power, to me it seems an obvious and inevitable move and the only thing that would even create an opportunity to electrify transportation. France showed this is settled economics, Hansen is helping to show it’s settled science, and it’s always been settled engineering. There is no degree of doomsaying that will get anyone to ignore the stuff that works for the stuff that doesn’t. The “delay” in addressing climate change is because climate activists (with the exception of people like Hansen) are coming late to the realism party. But they seem to think we have plenty of time to talk this out, so that’s good.

  4. Anyone who dies because of a 3 mm/year sea level rise deserves the Darwin Award.

    This is not a compelling narrative. If this is the best scare story there is, then all is lost. However at least you stated the current rate of rise, which is curiously never revealed in most MSM stories. But the NYT will run stories with Statue of Liberty underwater instead. 1 inch / decade isn’t exactly a call to action. Here’s a hint, Take two steps backward at the beach, you have 50 years to complete this action.

    High cost infrastructure can be protected. Everyone else can move, or adhere to stricter building standards over the next 100 years. If you build a house near the shore in Tampa now, you have to jack it up about 10 feet which wasn’t mandated 30 years ago. The changes in code aren’t due to global warming. So in 50 years the new code should say 10.5 feet.

    Almost all the hand wringing on SLR is artificial.

    • See Tom, that’s the point. Manila can’t do what you suggest. They already have had severe floods without climate change. They don’t need the extra aggravation. I’m surprised you can’t see that.

      • If Manila can’t do anything about flooding that happens without climate change, why do you think they will do anything about flooding with CC? Is there any data that says installing solar panels on the roofs of houses in New York is an effective approach to limiting flood damage in Manila? How does it compare – cost effectiveness wise – to, say, building a floodwall actually in Manila or showing them how to develop building codes?
        Is the suggestion here that we fund flood walls for Manila (and, presumably, every low-lying city on the globe)? If so, is this a higher priority than fully funding Obamacare, headstart, social security, medicare?
        If Manila is too poor to protect itself from flooding that will happen with or without CC, and the United States is unable or unwilling to fully fund global flood mitigation what is the best way to increase wealth in the Philipines so that they are not too poor to protect themselves?

      • Actually, that sort of protection is the kind of thing many (including myself) have called for. Flood walls, relocation, barriers at sea. That’s the $100 billion a year we used to talk about. Which I favor. With or without Climate Change. But more because of it.

        As for your second question–globalization, free trade, Doha WTO Round, etc.

      • You are not arguing about climate change, you are simply saying Manilla needs better flood protection. This argument is compelling and you will get a much more receptive audience for this. Either way you will be hard pressed to have the US taxpayer foot the bill. We can barely protect New Orleans.

        It is the “climate guilt” reasoning that causes vociferous blow back, and sets up a polarization that almost guarantees certain failure for the project.

        I basically stop reading anytime I sense a “climate justice” argument in the wind. It is almost always followed by twisted logic that the the US must pre-pay damages for future crimes to other countries. Very Minority Report.

      • I’m not one who opposes aid in general, although I think it should be centered on economic development. For example, access to low cost, reliable power.
        If Manila had access to a chunk of $100 billion today, where would sea walls, relocation and offshore barriers fall on the priority list of the people in Manila? Higher than medical care, shelter? Do they get a say or is this scientific colonialism?

  5. How are the Dutch doing? Sea level rise has been advancing there for 2000 years.

  6. Coastal flooding is a concern, but in many areas, including, I suspect, Manila, sea level rise due to climate change is a relatively minor factor. I’m a geologist and it bugs me when the media go on about sea level as if land elevation were fixed. There are several processes – sediment compaction, tectonic activity, post-glacial isostatic rebound – that can result in the land moving up or down more rapidly than the sea ever could. There are parts of the world, like northern Scandinavia or southern Alaska, where sea level appears to be falling. It isn’t of course, the land is simply rising faster than the water is.
    Sea level rise due to anthropogenic climate change may be real, but once you account for the natural background sea level rise that’s been going on for a century or more, and the natural rise or fall of the land level, the sea level change due to climate is likely to be down in the noise.

  7. Except 3mm is the multi-century average, I believe.
    TomL outlines reality-based concerns that we should be focusing on. Believing mitigation or reduction of CO2is the way to control slr is like believing a tuna can tune a piano.,d.dmQ

  8. hmmm…..try this:

  9. Many ancient cities in Europe have some quite fascinating sub-terranean archaeological sites going back 100’s or even 1000’s of years, and even relatively recent sities such as New York have some. Most of these were not built underground – cities tend to rise over centuries, in the case of London most of the tributaries of the Thames have been underground for many years, but they still flow downhill towards the sea. The islands in the Hudson have been deliberately raised and increased in size over the last century.

    My point is that you can be fairly certain that a city such as Manilla is rising constantly due to buildings being replaced, and overlaid with new developments, and the more primitive the city, the more likely it is to be rising by this method. At considerably more than 3mm per year. The City of London has an elevation of approx. 9m compared to approx. 0m in Roman times, an average elevation of 4.5mm per year.

    • Maybe. But a lot of Asian cities (eg. Tokyo) are sinking due to subsidence. Pulling too much water out of the aquifers.

  10. Nullius in Verba

    I don’t know about other people, but I seem to remember being taught the *reason* for so many patches of land being so flat in geography 101 at school – it was virtually the first topic we did. Rivers driven by gravity carry sediment downriver until they reach sea level, where they drop it. More sediment results in a bigger area covered, not a higher altitude. It is no accident that so much land is so close to sea level – sea level is what causes it! Those flat and fertile patches that people like to live on are bits of the sea that have been filled in, by floodwaters carrying sediment there and dropping it.

    So the fundamental question is not how long it will take for 3 mm/yr to overtop the land where it is now, but how fast the land can rise compared to the sea.

    The problem of modern flood defences interrupting the natural land-building process is a separate one, to which we will have to find a solution anyway. Sediment compacts and sinks, and erodes at the edges, and if we stop new material coming in we will have problems. But the most important missing part of any such discussion is the recognition that land is dynamic, it rises, falls, accumulates and erodes in dynamic equilibrium, and it always has and always will, and it is a problem we are already very well used to dealing with.

    • Please get quantitative about that.

      Your argument is silly. Sea level rise of the order of a meter (or perhaps more) per century is not balanced by any reasonable rate of land “rising and falling”, and the process of alluvial deposit is in any case utterly dierupted by anthropogenic processes in most basins nowadays.

      The previous rapid sea level rise at 14Ka was a worldwide coastal flood. There wasn’t any civilization at the time. Had there been, it would have been very messy.

      • Actually, 7KY later we do have evidence of the disruption caused when the English Channel flooded and the Digger culture was more or less inundated up to the North Sea. And it was very disruptive. But this is not projected to happen under any realistic scenario for more than a thousand years. Why are you bringing this up? Nobody sees this happening. You are bringing science fiction scenarios into a scientific argument. Do you really want to stoop to the stupidity of Oreskes and Conway? Doesn’t science mean anything anymore?

      • My understanding from the people who actually study it is that they aren’t sure when it will happen. As usual, scientists don’t like saying “not sure” publicly so there isn’t much in press. This notoriously affected AR4.

        Ice sheets are much more complicated than they look, it has recently emerged. So in fact, we don’t know.

        “Some recent observations suggest
        a rapid dynamic response of the
        Greenland and West Antarctic Ice
        Sheets, which could result in an
        accelerating contribution to sea-level
        rise. This has been included in an
        ad-hoc fashion in the projections.

        For the Greenland Ice Sheet, proposed
        mechanisms of the response include:
        surface melt water making its way to
        the base of the ice sheet, lubricating
        its motion and allowing the ice to slide
        more rapidly into the ocean; and the
        decay of ice shelves and the loss of their
        ‘buttressing’ effect on the seaward
        movement of the outlet glaciers.

        In Antarctica, the West Antarctic Ice
        Sheet is grounded below sea level,
        which allows warmer ocean water to
        melt the base of the ice sheet. This
        could potentially lead to significant
        instability of the ice sheet, particularly
        if the ‘buttressing’ effect of the seaward
        ice shelf was lost.

        Our understanding of these processes
        is limited. As a result, they are not
        included in current ice sheet models
        and there is no consensus as to how
        quickly they could cause sea level to
        rise. Note that these uncertainties are
        essentially one sided. That is, they
        could lead to a substantially more rapid
        rate of sea-level rise but they could not
        lead to a significantly slower rate of
        sea-level rise.”

      • Wow. I didn’t know that Greenland is a completely smooth flat contry below the ice, so that the entire ice mass could slide off into the sea at any moment. Scary.

      • One of the more entertaining aspects of AGW culture is how they derivatively and apparently unconsciously cycle between old SF b movie plots and stories. I always thought ‘living in the age of science fiction’ would mean affordable space travel, smart robots, etc. Instead I am realizing it means living with a bunch of people who confuse science fiction with reality.

    • spangled drongo

      Yes NIV, it’s one of the first things you learn when you play mud pies as a kid. How the drains deposit the silt and create all the delta islands at existing water level.

      There is current agonising over the SLR disasters at the “cradle” of civilisation ie the Nile Delta when what is really happening is delta starvation due to Nile Dams plus the natural erosion of a lee shore.

      Alexandria is another Manila with a self imposed problem. SLs were probably higher when it was first built than today.

  11. I think this post highlights (using one example of sea level change in Manila) that we need accurate climate and sea level forecasts based on reality not politics or ulterior motives.

    On top of that, even if climate sensitivity turns out to be exactly 3C, that still doesn’t mean that constructing 100 wind turbines in Timbuktu is going prevent flooding in Manilla. In other words, the policy response has to make sense as well, e.g. help Manila build sea protection infrastructure.

  12. I’m pretty sure the actual scientists who are studying coastlines understand the difference between sinking land and rising water. The problem is that so many of the media and politicians remain wilfully ignorant of the basics of coastal processes.

  13. I think we could call in some Dutch engineers to give advice. Their great-great-great-… grandfathers provided a solutuon for Holland.

  14. Nullius in Verba

    “Please get quantitative about that.”

    If you like. 🙂

    “Your argument is silly. Sea level rise of the order of a meter (or perhaps more) per century is not balanced by any reasonable rate of land “rising and falling”,”

    OK. Satellites indicate a current rate of rise of 33 cm/century, so a 1 m/century rise is about 3 times that, and therefore the same sediment would have to deposit on a third of the area to match the rise – a pessimistic back-of-envelope approximation that ignores lots of stuff about changing shoreline erosion rates, gradient profile, compaction rates, proportion of sediment dropped, and so on. And also assuming that we didn’t do anything technologically to help the deposition process along.

    So, quantitatively speaking, you would potentially lose up to 2/3 of the low-lying land to less than a metre depth, probably a lot less, which would therefore require some sea reclamation-type engineering to retain. For example by building settling pools to retain more of the river sediment, or increasing erosion upstream. Or designing new buildings with thicker foundations. Or simply building a wall around it all, like the Dutch.

    Or even more simply you can move out. Houses are replaced on a 50-100 year cycle, anyway, and lots of people move house at a rate of more than once per century. This is well within the bounds of current urban redevelopment and mobility. Many of those cities were built in less than a century. It would take less time than that to build a new one elsewhere, without even having to go to any additional effort.

    That’s all hypothetically speaking, of course, in the case of a “silly” 1m/century rise. It would require something like an ice sheet collapse, which as we’ve previously discussed elsewhere is wild speculation based on crude models making unrealistic 2D assumptions.

    So to be clear, even supposing you’re right about high sensitivity warming, and that further this leads to an unrealistic-sounding ice sheet collapse, and further that this happens extremely rapidly, then it would still be within our current technological capabilities to cope, let alone the capabilities of people who are to us as we are to people of the 1920s. Plus being twenty times wealthier, and all that. It doesn’t sound to me like there’s any reason to panic.

  15. SLR is one of the more popular vampire arguments the AGW faithful endlessly recycle.

  16. spangled drongo

    I don’t think the ice sheets are causing any SLR. Where I lived by the bay 67 years ago the SLs now are, if anything, lower than then.

    Here is a recent scientific paper showing the Arctic ice sheet is accumulating at the rate of 86 Gt/year from 1840 to 1996 which is 30% higher than the 1600 to 2009 period which suggests an ACCELERATING trend of ice growth:

  17. Baloney.

    I grew up in Manila. In 1976, we had torrential that flooded most of centra Luzon. At that time, natural waterways were unblocked. Over the years, through wanton disregard, natural waterways have been covered by subdivisions.

    The dams in the Philippines are so silted from the denudation. The pasig river and Manila bay are not dredged the way they should be. In fact, when the suppossed expense fro dredging were audited when Marcos fell, the amount of claimed silt would have created an island larger the Corregidor.

    The malabon lagoon was completely destroyed by the dagat-dagatan project, which causes the flooding during high tides and drizzles.

    By the way, Manila is really below sea level. There are pumps that should e working preventing flooding in areas close to the mouth of the river.

    If money is spent correctly there would be no problem. There definitely is wanton disregard about the environs in the Philippines. I believe this can create havoce to the micro-climate. But global warming and sea-level rise is just baloney. You are giving an excuse for the corruption to continue.

  18. spangled drongo

    Federico, well there you are, ASLR ☻

  19. Just a correction. The floods were in 1972. Look it up on any search engine. If Luzon ever gets the same 20+ days of continuous rain like we did in 1972, the devastation would be horrendous and clowns like TomL will claim proof of global warming.

    This has happened before and will happen again. Because of corruption and greed in Manila, it will be catastrophic the next time it happens.

    Also, if I am not mistaken, the funding for dagat dagatan came from the world bank. Next time the world bank and IMF lends money, they may as well ask for the swiss account number and save the trouble by depositing the money directly. Off course the WB and IMF scumbags will not care that the repayment will come off the blood, sweat and tears of the ordinary Filipino.

    • New Orleans was not flooded by Katrina. New Orleans was flooded due to corruption.
      Federico makes a good point. Like African famines, it is not really the droughts or locusts. It is corrupt government policy, not rain that leads to hunger.
      Yet AGW fanatics look to government for the solutions.

      • Guv’mint has done some good things, too. Trick is knowing what it’s good at and sticking to it.

      • Defense, police powers, common areas like roads and canals, if properly funded. not funding education at the micro-mgt level, no longer postal service, certainly not funding media/news. some generic support of arts,

  20. Tom, a while ago I promised you an article on sea level. The paper I was waiting for has been pulled from publication. I don’t know why. The gist was that there are two systematic errors in sea level change. Both tend to inflate the rise. Gauge settling is well documented. The other is that in satellite measurements, the average change in continents surface height is is forced to zero. The oceans aren’t. I may never see the calculations so I will not comment on this again.

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