Palko writes:
A common, perhaps even the standard framing of rising sea levels is that it’s a existential threat for all coastal cities, and while I understand the desire not to downplay the crisis, this isn’t true. For cities with relatively high elevations like Los Angeles (a few low-lying neighborhoods, but most of it hundreds and some of it thousands of feet above sea-level) or cities with at least moderate elevations and little danger from tropical cyclones (like almost all major cites on the West Coast), we are talking about a problem but not a catastrophe . . . the real tragedy of this framing is not that it overstates the threat to the West Coast, but that it dangerously understates the immediate and genuinely existential threat to many cities on the East and Gulf Coasts. While New York City is not in danger of total oblivion the way Miami or Jacksonville are, it is far from safe from the threats associated with rising sea levels. . . . This is one of the things that makes the following New York Times article from a while back so strange.
An estimated 600 million people live directly on the world’s coastlines, among the most hazardous places to be in the era of climate change. . . . Many people face the risks right now. Two sprawling metropolitan areas offer a glimpse of the future. One rich, one poor, they sit on opposite sides of the Pacific Ocean: the San Francisco Bay Area (population 7 million) and metropolitan Manila (almost 14 million).
Their history, their wealth, and the political and personal choices they make today will shape how they fare as the water inevitably comes to their doorsteps.
Palko continues:
The New York Times felt the need to go all the way to San Francisco to do the story despite the fact that New York City has more people, lower elevation, and faces a far, far greater risk from tropical cyclones. This is not quite as bad as the San Francisco Chronicle doing features on earthquakes and wildfire smoke and using NYC as one of the two examples, but it’s close. . . .
The different elevations of Manila and San Francisco and how they affect the impact of rising sea levels is largely undiscussed. There is exactly one mention of tropical storms, none whatsoever of tropical cyclones, and the fact that certain areas are more vulnerable than others is almost completely ignored. All coastal cities are treated as effectively interchangeable. . . .
The all coastal cities are equal narrative embraced by the New York Times is extraordinarily dangerous. It inevitably underplays the to cities from New York all the way to Houston along the coast, particularly in Florida . . .
I continue to think that Mark Palko and David Weakliem should have columns in the Times. Not that they’re perfect, but both of them seem to have the ability to regularly see through the fog of news media B.S. that surrounds us.
Where does the news media B.S. come from? Some of this is bias, some is corruption, but I think a lot is simple recycling of narratives that for one reason or another are appealing to our tale-spinners.
If we are to have a “rational” evaluation of the risks, then the geography (elevation, topography, etc.) are certainly relevant. So, too, is the wealth of an area – its ability to finance adaptations that could reduce the impacts of rising sea levels, more intense storms, etc. The economic conditions make climate change more of an “existential threat” for poor countries almost regardless of the physical characteristics. A more complete picture of impacts and potential mitigation measures is clearly called for, and the media reporting is, at best, uneven.
But there is another dimension to the problem that I think gets too little attention. I’m not sure what an “existential threat” really means: does it depend on x number of lives at risk, $y costs of damage, or some other measure? For me, the “existential threat” is neither of those – it is the uncertainty about the impacts of the scale of human impacts on the environment. Rich countries can afford to deal with climate change – there will be geographical differences, but I suspect the impacts are affordable and loss of lives will not be great. In poor countries, some impacts may not be affordable and loss of lives may be considerable. But, for me, rising sea levels (on the scale and time we are talking about) are symbolic of bigger issues. Species extinction, ecosystem damage, potential system instabilities, and socioeconomic/political impacts, all subject to huge uncertainties – these are the issues that climate change represent in my mind. So, I’m all for a more rational evaluation of the more well defined risks associated with climate change, but let’s not ignore these less measurable potential impacts.
‘…I’m not sure what an “existential threat” really means…”
“Existential threat” is just another empty woke term and much like the rest of that vocabulary means little.
An existential threat is something that threatens one’s existence. Like, if sea levels rise too much on the coast, city X may cease to exist. Hence, rising sea levels are an existential threat to city X.
Yes. I can see the argument that the term is overused, but so say it doesn’t mean anything…that’s just not true, it has a clear meaning.
If a city would cease to exist from a 1 m rise in sea level over 100 years, it was doomed anyway.
The problem is that everything becomes an “existential threat” to fragile systems, which is when the term loses meaning.
Anon,
You say “If a city would cease to exist from a 1 m rise in sea level over 100 years, it was doomed anyway.” That’s kind of silly. About 40% of Ho Chi Minh city is less than 1 meter above sea level. As far as I know, the city faces no other evident existential threats. It is not the only city in this situation.
The people in a city have 100 years to gradually adjust land use, build levees/seawalls, change construction practices, etc. As one area gets damaged it should get replaced with something more robust.
If such simple measures aren’t happening, the city must be too dysfunctional to perist. We aren’t talking about huge amounts of resources when spread over a century.
Eventually such a city will burn down or become a slum/ghostown or whatever due to incompetence and corruption.
Anon,
If you don’t know what you’re talking about, please don’t write as if you do. Sometimes you really _do_ know what you’re talking about, and in those cases I appreciate your comments. But your signal:noise ratio is pretty low and, although I may be wrong, I fear it is getting lower. I think a lot of people who read this blog regularly have pretty much given up on trying to get anything useful out of your posts; I haven’t done that yet but I’m on the fence.
In this specific case, you’ve got a sort of high school-level view of what it takes for a city to adapt to sea level rise. Build a seawall, build houses higher in the future when they get flooded now, it’s not a big deal. You might also badly misjudge the resources available to less affluent countries, although I can’t tell that for sure. You aren’t wrong that these sorts of measures are necessary to preserve a city, but you’re badly wrong about them being sufficient. I’m not going to bother listing reasons; if you want to learn them you can look them up yourself. Or perhaps you can even think of some! You’re a pretty smart guy, I think, so I’m guessing you can think of at least three major problems the city would face even if it were completely surrounded by a 100% impermeable and un-toppable seawall.
Phil,
Can you name a single city in history abandoned due to a gradual sea/river/lake level rise at a rate of something like 1 m per century?
I can’t find one. There are many that adapted, or were destroyed by much more sudden catastrophes though. So once again we are back to me arguing with a person assuming something unprecedented will happen by default.
I assume things that have happened before under similar circumstances are most likely to happen again by default. That seems to be the main difference between what I think and those that have “given up” on me who regularly assume “the sun will rise in the west” until proven otherwise.
I suspect the real concern is something like storm surge, not a 1 meter rise per se.
In that case is there really a difference between preparing for a 5 meter surge vs 6 meter, or 10 vs 11 m? That is a rounding error.
I really can’t think of any reason to be concerned about such a small, slow rise in sea level that isn’t already addressed by preparing for the types of catastrophes we have seen happen over and over throughout history.
Anon
You really are intent on harping on the same points, to the exclusion of any other ideas. I will agree that it is important to be more specific about what the dangers really are, and what other risks we compare them to. Sea level rise in itself is a limited concern – although more for some places than others. There is a village in Alaska that is likely to be underwater within our lifetimes – you may dismiss those concerns as non-consequential and just like historical episodes, but for the residents I suspect it is more serious – and it is happening more quickly due to human actions (yes, there is arguable evidence here, but I believe that is off the point). In the grand scheme of things (meaning for the rest of us), that is a minor issue – certainly less of a risk than EMPs, etc.
But what you keep ignoring is that the concern over sea level rise, while perhaps misplaced, is a more general concern with impacts of human population, consumption, and technology – I continue to be concerned about the scale of our impacts and the large associated uncertainties. Sea level rise is but a symptom of these problems – ridiculing it (as you do) becomes a way to discount all the concerns it might represent. And the self-assuredness with which you declare things further discounts people’s concerns. It is helpful to better define the risks, but I don’t think it is helpful to discount their concerns.
This is informative:
> “The analysis demonstrates that a large number of people are already exposed to coastal flooding in large port cities. Across all cities, about 40 million people (0.6% of the global population or roughly 1 in 10 of the total port city population in the cities considered here) are exposed to a 1 in 100 year coastal flood event.
The exposure is concentrated in a few of the cities: the ten cities with highest population exposure contain roughly half the total exposure and the top 30 cities about 80 percent of the global exposure. Of these thirty cities, nineteen are located in deltas. For present-day conditions (2005) the top ten cities in terms of exposed population are estimated to be Mumbai, Guangzhou, Shanghai, Miami, Ho Chi Minh City, Kolkata, Greater New York, Osaka-Kobe, Alexandria and New Orleans.”
https://climate-adapt.eea.europa.eu/en/metadata/publications/ranking-of-the-worlds-cities-to-coastal-flooding/11240357
“Can you name a single city in history abandoned due to a gradual sea/river/lake level rise at a rate of something like 1 m per century?”, I dunno, how about giving me a list of cities that have faced that, and we can discuss the extent to which they were ‘destroyed’?
Or we could discuss Venice. Venice is probably going to survive for another hundred years, because it’s a gem that brings in zillions of dollars in tourism, and is in a major industrialized country, and is situated inside a ring of barrier islands that makes it (barely) possible to engineer a solution that only costs tens of billions of dollars rather than hundreds of billions. Venice’s situation does not bolster your argument.
The really telling part of your commentary is in a later comment, though: “I really can’t think of any reason to be concerned about such a small, slow rise in sea level that isn’t already addressed by preparing for the types of catastrophes we have seen happen over and over throughout history.” Exactly. You can’t think of any reason to be concerned…that’s fine. But earlier you made a much stronger claim that “If a city would cease to exist from a 1 m rise in sea level over 100 years, it was doomed anyway”…not just that you can’t _think_ of a reason we should be concerned, but that there _is_ no reason to be concerned. If you were some kind of expert on this, or had even looked into it in a serious way for a couple of days, those might not be very different. But since you don’t know what you’re talking about those are very different indeed. Which is fine! You don’t have to be an expert on everything! All I ask is that when you don’t know what you’re talking about, you avoid acting as if you do. It wastes my time and reduces your credibility.
Well, I’ve personally been to Amsterdam, Venice, and New Orleans. Probably also many of these cities: https://en.wikipedia.org/wiki/Venice_of_the_North
There are also the “Venice of the East” cities. It seems the cities that adapt actually prosper during the mitigation of water level rising. Maybe there is survivorship bias going on but when I tried to find examples of cities that were destroyed/abandoned due to a slow rise, I could find none. There was plenty of speculation that ignores the success stories and scary maps of cities that will be underwater in the future though.
And if you read my other posts in this thread, you will see I am actually very concerned about sea level rise (and the CME/EMP threat). This is definitely something that should be planned for, but planning for 1 meter over a century is pointless. That isn’t something worth worrying about except at a very local level, which has already been done for thousands of years.
Address the actual prominent threats first, and minor threats like that will also be taken care of.
The term “existential threat” was popularized by foreign policy circles in the USA trying to justify US military spending after the Soviet Union collapsed. It was popular with the second Bush administration. Whether Dick Cheney was woke I leave as an exercise for the reader.
Part of the problem is that people tend to use existential threat to human kind and existential threat on a more local scale (e.g., existential threat to an island or a city) interchangeably, on the context of threat from climate change.
A climate change threat that’s reasonably considered “existential” for a given community doesn’t translate as an existential threat for people in other communities.
What’s particularly problematic about climate change risk is that the “existential” threats are to communities that have done much less, relatively, to create the threat.
That’s also why it’s a bit problematic foe people in rich countries to diminish the “existential” nature of the threat from ACO2 emissions
These are great points. Along these lines
1. “Existential threat” is dangerously overused, which perversely creates a boy who cried wolf problem
2. Wealth and ease of mitigation have to be part of the story
3. That said some areas are so screwed that money won’t help. Between sea level, hurricanes, and contamination of the aquifers, much of Florida does face an existential threat from climate change
4. Perhaps the weirdest aspect of the discussion is the focus on existential threats as a standard. Lots of outcomes are horrifyingly bad without meeting that standard.
5. We should talk more about ocean acidification.
I’m not sure people are aware that sea levels appear to have risen 10x faster in the past, and it seems to have been quite catastrophic:
https://en.m.wikipedia.org/wiki/Meltwater_pulse_1A
And further that the levees along the southern course of the mississippi river were only 1 meter tall 100 years ago, now they are 7 meters since the water level has risen that much.
This is the type of climate change we should be preparing for, along with a coronal mass ejection or EMP burning out the power grid.
One meter of sea level rise over 100 years is a very minor fluctuation, and any solution to problems caused by historical rates of climate change will easily address that.
> And further that the levees along the southern course of the mississippi river were only 1 meter tall 100 years ago, now they are 7 meters since the water level has risen that much.
It’s unclear if you’re suggesting that the rise in the sea level produces higher floods upstream or that it’s the floods that cause the sea level to rise…
The water level rose because levees were built upstream, which keeps more water confined to the (relatively narrow) river.
I think it is important to keep things in context. It appears that Pulse1A was around 14,000 years ago. Human population was around 1 million 10,000 years ago, and perhaps around 100 million 1000 years ago (https://en.wikipedia.org/wiki/Estimates_of_historical_world_population#Before_1950). Early humans were more nomadic that current humans, and far smaller in number, while ecological diversity was much larger (some issues of measurement here). So, the more rapid sea level rise in Pulse1A had far different implications than today’s.
But I will grant the point that the sea level rise itself is overblown as an existential threat, except for particular locations and populations. And, if we want to focus on sub-populations, there are other existential threats that are arguably worse (e.g. malnutrition). So, I don’t like the term “existential threat” nor do I think the binary thinking it implies is helpful. However, I do view the sea level rise as one indicator of the scale of human impact, and I find that scale worrisome and fraught with uncertainties. Extinctions (https://ourworldindata.org/extinctions) are a similar phenomenon to sea level rises: there have been mass extinctions, perhaps larger (but perhaps not as rapid) than we face today. But I find little solace in the historical comparison.
Lots of arguable assumptions go into these estimates of what happened thousands of years ago.
But the point is (if you trust that data/interpretation) our civilization should be prepared to deal with something more like 10 m of sea level rise over 100 years (along with the CME/EMP threat). We already have evidence of those things happening.
Addressing those threats will also address the 1 m rise supposed to happen due to CO2 emissions, but that isn’t true vice versa. In fact, the solutions proposed for the 1 m rise will make us more vulnerable to the bigger threats.
Meanwhile we have an example of how to deal with a much larger rise in water levels. New Orleans for instance has built about 350 miles of levees (mostly around 7 m tall) for a city of population ~0.5 million. So that is resources devoted to building 700 miles per million pop over 100 years, and it wasn’t a huge deal. Scaled to the entire population of the US would give 200k+ miles, while the entire coastline is only something like 10-100k miles.
Of course, the coast isn’t exactly the same as the river, only certain parts of the coast need be protected, and levees are not the only engineering solution introduced, modern tech is presumably superior to what was used in the 1900s, etc. But as a rough order of magnitude that gives us an idea of what humans can deal with.
One meter rise does not seem like a threat to worry about when there are much bigger threats out there.
But people in NYC live in high rises made from stone and metal, putting them at lower risk than West Coast dwellers who live in single story stick frame houses.
Local and regional geology are ***the major factors*** controlling local relative sea level rise (RSLR). It’s amazing that people keep talking about sea level rise with absolutely no reference to local and regional geological features, because it has a huge impact on the need for mitigation. The entire west coast has substantially lower RSLR than the east coast.
Check out the map on this page and click on a few of the gauges represented by the green pins:
https://cwbi-app.sec.usace.army.mil/rccslc/slcc_calc.html
Here are roughly representative local sea level trends:
Cape Flattery, WA: -1.6mm/y (sea level falling!)
Point Reyes, CA: +2.1mm/y
Long Beach, CA: +0.78mm/y
Galveston Pier, TX: +6.84mm/y
Grand Isle, LA: +9.24mm/y
St. Petersburg, FL: 2.36mm/y
Daytona Beach, FL: 2.32mm/y
Charleston, SC: 3.15mm/y
Chesapeake Bay Bridge Tunnel: 6.05mm/y
Atlantic City: 3.99 mm/y
The Battery, NYC: 2.77mm/y
Bah Habbah, ME: 2.04mm/y
Here are some fundamental realities:
1) RSLR on the west coast is substantially less on average than on the east coast. This is a direct result of the tectonic regimes of the two regions: shortening and therefore relative uplift on the west coast and trailing margin and therefore relative subsidence on the east coast.
2) Rocky coastlines experience less RSLR
3) “Soft” or depositional coastlines, like the US east coast between NYC and Jacksonville, or the Gulf coast west of Florida, experience much higher RSLR rise because of sediment compaction and subsidence.
4) Developed soft coast lines experience even higher relative sea level rise because development prevents deposition of the sediment that would normally keep pace with subsidence
5) Florida has lower relative sea level rise than the central east coast or gulf coast, but it’s a special risk case because of the porous limestone substrate that occurs in some areas.
6) spits, barrier bars, estuary islands, etc are all ephemeral under normal conditions. As a rule, changes in these environments are dominated by changes in sediment deposition patterns, not by SLR.
On average, though local conditions vary, the US west coast has **far** less to fear from SLR than the east coast. The topography is a result of the fundamental geologic factors that underlie RSLR. Regions of crustal shortening / compression, which have less RSLR, will have topographic variation that scales with the rate of shortening. Regions with widespread subsidence have greater RSLR and subdued topography.
I forgot the plus signs on several data but all shown are positive except Cape Flattery, WA.
Note that most of almost all of the stations around the Gulf of Alaska are strongly negative – local sea level rising – due to the tectonic regime (subducting margin / shortening crust):
Ketchikan: -0.19mm/yr
Juneau: -12.92mm/yr
Nikiski: -9.8mm/yr
Anchorage : + 0.88mm/yr
Kodiak Island: -10.42mm/yr
Note that Nikiski and Anchorage are dramatically different even though they’re close to one another. The difference is that Anchorage is located on a river mouth, which probably is there because it’s on a subsiding tectonic block.
Ha!! “note that…” :)
I need to start checking that site, thanks.
Ironically, California does face a huge threat from flooding, but it’s in the Central Valley, not on the coast.
And there’s one non-local factor: the crustal rebound from melting ice. So seas are subsiding in Norway and Eastern Canada as the land continues to recover from being under ice for much of the past 100,000 years, and ice melting in Greenland has a larger effect on sea level rise on the West Coast of the US than the East Coast (counterintuitive but true).
Huh?
I don’t get the level of criticism. We can walk and chew gum at the same time.
Seems to me the framing of the story is to contrast two cities on Pacific Ocean coastline, to show that although wealth can mitigate risk from SLR, there’s a limit to how much protection what wealth brings.
Nothing about that framing suggests that geography or factors like average elevation above sea level aren’t important. I wouldn’t finish reading the article thinking that San Francisco is more at risk than NY or Miami.
> The New York Times felt the need to go all the way to San Francisco…
That framing bugs me. “The New York Times” doesn’t “feel” needs as some kind of collective entity. Some editors decided they liked the framing of comparing contrasting cities on the opposite sides of the Pacific. That doesn’t mean as a collective entity it elevates risk in SF disproportionate to the relative level of actual risk in NY. The Times has certainly published many articles about the implications of sea level rise in NY.
The NY Times, as a collective entity, certainly deserves many criticisms. Indeed, the way the paper interrogates the notion of “catastrophe” w/t/t climate change is a good subject for questions. But some times I think it’s too easy to fall into an “old man yelling at clouds” mentality when critiquing the paper. This seems to me to be one of those times.
I see this as a problem of insufficient subject knowledge on the part of reporters and editors, which is enormous in many aspects of climate change. Sadly, this is true even after decades of (partial) engagement with this issue.
I didn’t discuss this in my book — it would have been a diversion — but SLR is widely misunderstood. First, it’s true, as Chipmunk said, that whether there is local uplift or subsidence apart from changing sea levels is very important. This has general implications for different coastal regions but also for much finer-grained delineations. A few miles along the seismically active PNW coast can make a huge difference in relative local SLR.
But the bigger issue, which the media have not clarified despite the fact that it drives many of the disasters already taking place, is the SLR will not be experienced — is not currently being experienced — as a gradual retreat of the coastline, but in increasingly extensive storm inundations. This is a simple matter of topography. It’s here especially that expenditures on infrastructure can make a difference, up to a point. Of course, this risk is exacerbated by the increasing frequency and strengths of such storms to begin with. I remember teaching a class on this topic about 15 years ago, and still it hasn’t made its way into popular discussion.
There’s a book to be written on the gaps and misrepresentations in media coverage of climate change, but it would be too depressing to read.
Andrew writes, “Where does the news media B.S. come from? Some of this is bias, some is corruption, but I think a lot is simple recycling of narratives that for one reason or another are appealing to our tale-spinners.”
As a long time reader of the NY Times and WaPo, the lack of critical thinking is the one apparent problem that both papers suffer from. Anyone is a modicum of knowledge of geography and weather can easily do a rough risk calculation of what regions will be most at risk from climate change, which includes both sea level rise and increased violent weather.
Also:
1) Any slowdown in Gulf Stream causes more water to pile up along East Coast.
2) Melting of Greenland reduces its gravity, which means more water nearer Equator (modest effect, but relevant to East Coast).
3) Higher sea level does not just affect shore, but when heavy rainfall, backs ups into coastal rivers, of which East Coast has many more.
4) East Coast has much more building right on low coast, whereas such is forbidden along much of West Coast.
5) But SF Bay Area still has issues.~15 years ago, I attended an all-day symposium for town planners on planning for SLR in SF Bay Area. It started with talks by climate scientists, then talks by several town officials about actions, then a talk by a dike expert. Then we split into groups, each given a description of an imaginary SF Bay shore town and asked to plan for 50 years. Technical and political difficulties surfaced quickly.
a) Sewage systems are ideally located below houses but above sea level.
b) If intending to build dikes, better coordinate with adjacent towns.
c) Statiscal uncertainty matters a great deal in economicially-efficient planning, as overbuilding dikes or condemning shoreline property early costs $, as does underbuilding or allowing building in bad places.
d) Politics: it might be best to define a defendable line higher than the shore , rather than building lower dikes at the shore, but those in between will not be happy.
For those interested in more, several good books are:
Jeff Goodell, The Water Will Come, https://www.amazon.com/Water-Will-Come-Remaking-Civilized/dp/031626024X
Brian Fagan, The Attacking Ocean, https://www.amazon.com/Attacking-Ocean-Present-Future-Rising/dp/1608196941
https://www.amazon.com/Water-Will-Come-Remaking-Civilized/dp/031626024X
In IPCC AR5, the 5th assessment report in 2013, sea level rise projections for 2000-2100 for CO2 emission scenario RCP8.5 was under 1m with slightly later work saying there was a small chance of a 2m rise.
RCP6 was 0.3m to 0.6m.
RCP8.5 represents a huge increase in CO2 emissions, something like burning 5-6 more coal by the end of the century. It’s known as the “business as usual scenario”.
RCP6 is roughly where we will be by 2100 if we don’t make significant changes to CO2 emissions.
Unfortunately, none of this is well known. Every time climate scientists are quoted in the media it’s “we could see many meters of sea level rise by 2100”.
Sea level rise is real, it’s a result of global warming, which is a result of burning fossil fuels. Sea level rise is a problem.
But it’s worth knowing realistically how much sea level rise can be expected. Wild exaggeration is what characterises climate science in the media vs IPCC reports and papers.
—-
Notes:
1. Anyone interested in the details of RCP8.5 not being “business as usual” could look up Zeke Hausfather’s January 2020 editorial in Nature “ Emissions – the ‘business as usual’ story is misleading”. Or ask, and I’ll provide the relevant pages of the IPCC report that give the CO2 concentration values for RCP6 and RCP8.5 in 2100.
2. AR6 was published this year, with slightly different scenarios and slightly different results. From a quick scan there’s nothing significantly different.