Rising Seas Will Erase More Cities by 2050, New Research Shows

https://www.nytimes.com/interactive/2019/10/29/climate/coastal-cities-underwater.html

by uptown • 7 years ago

67 89 7 years ago

nytimes.com

brohoolio• 7 years ago

Did I just miss the link to the research material?

How much higher will it be? 6 inches? 2 feet?

luu• 7 years ago

I believe the paper is https://www.nature.com/articles/s41467-019-12808-z.

If I'm reading the paper correctly, the authors don't argue that sea levels will rise more than previously predicted. Rather, they argue that the classical technique for estimating impact by using elevation (SRTM) is overestimating elevation and therefore underestimating the impact of rising sea levels. The authors claim that their technique (CoastalDEM) also underestimates the impact of rising sea levels, but reduces the systemic bias present in previous estimates.

radford-neal• 7 years ago

Thanks for the link. One statement from the paper: "this analysis assumes a static coastal topography".

This seems like a significant limitation, especially when a lot of the affected area consists of river deltas (eg, most of Bangladesh, the Mekong delta in Vietnam). One would expect that a rise in sea level in a delta would lead to increased silt deposition on the newly-submerged parts of the delta, reducing the impact compared to a naive calculation, perhaps quite significantly.

listenallyall2• 7 years ago

"Central estimates in the recent literature broadly agree that global mean sea level is likely to rise 20–30 cm by 2050 ref.3,4,5,6,7,8,9,10"

But what the paper is claiming, is that accepted methods of determining elevation are positively biased (estimates of land mass being higher than this new paper says):

"CoastalDEM reduces linear vertical bias from 4.71 m to less than 0.06 m."

IanDrake• 7 years ago

More? I can't think of one that's been erased yet.

asah• 7 years ago

More by 2050 i.e. more than previously predicted by 2050.

mikhailfranco• 7 years ago

Indonesia is moving Jakarta's capital status and government functions to a new city on Borneo. Of course, they cannot move Jakarta itself, which is also sinking due to groundwater extraction, and will be flooded unless they build a costly barrage system. They need to get the Dutch back to show them how (the Dutch will need a place to move anyway :)

Thailand is also discussing a similar plan to move the capital from Bangkok to Ayutthaya, the historical capital before the Burmese invasion of 1767.

New York is planning a sea wall system in southern Manhattan - The Big U - but what they really need is a truly BIG barrage from Long Island to Staten Island across the Narrows, and a smaller effort between the island and the New Jersey mainland. Closing the East River will be more difficult, depending on how much of the shoreline will be included. By coincidence, the Dutch also used to control New York.

arkades• 7 years ago

Does anyone have any sources for good projects for the USZ?

steve19• 7 years ago

At what point do we first see mass floodings from unusually high tides, such as during proxigean spring tide? Surely it must be soon if Veitnam will be underwater in just 30 years time?

catalogia• 7 years ago

Apparently it's already happened.

The findings don’t have to spell the end of those areas. The new data shows that 110 million people already live in places that are below the high tide line, which Mr. Strauss attributes to protective measures like seawalls and other barriers.

ekianjo2• 7 years ago

So basically we have 110 millions of people living in "dangerous" areas so far yet nobody was impacted?

comicjk• 7 years ago

Hurricane Sandy hit NYC during a spring tide, flooding downtown and knocking out power and a lot of subway tunnels. It cost 53 lives and about $19 billion.

https://en.wikipedia.org/wiki/Effects_of_Hurricane_Sandy_in_...

klyrs• 7 years ago

https://www.nature.com/articles/s41467-019-12808-z

pmiller2• 7 years ago

Over all, the research shows that countries should start preparing now for more citizens to relocate internally, according to Dina Ionesco of the International Organization for Migration, an intergovernmental group that coordinates action on migrants and development.

How the hell is Vietnam supposed to prepare for non-existence?

sithadmin• 7 years ago

It doesn't have to? Look at a map of Vietnam, then look at the (relatively small) portion of Vietnam presented in the article's graphics...

NeedMoreTea• 7 years ago

A "relatively small" portion that's still a major territory loss that includes everything south of Ho Chi Min, and much of the city - of 10m. I'd say they have to. Perhaps quickly as these estimates appear to be based on RCP2.6 - that's the most optimistic track assuming everyone is meeting Paris goals. Right now, no one is.

wsc981• 7 years ago

Makes you wonder when coastal property prices start plummeting. And when banks stop granting mortgages for buying coastal homes. I don’t believe this is happening yet.

rectang• 7 years ago

Is there a way to short these real estate investments and fleece climate-change-denying ideologues who are keeping coastal property values high? Do well by doing good! :D

listenallyall2• 7 years ago

Climate-change-denying ideologues like the Obamas? Or are you the one being duped?

https://www.google.com/amp/s/www.masslive.com/capecod/2019/0...

badfrog• 7 years ago

If there was, you'd probably be paying a lot to hold the position for 30 years.

CydeWeys2• 7 years ago

It's gonna happen over too long of a time horizon (from now, anyway) to profit handsomely off of. There are much better investments you can make today because they will pay off sooner.

shams93• 7 years ago

Yeah so far coastal prices are far above the inland prices

GenerocUsername• 7 years ago

Oddly lots of rich and connected are buying coastal properties... You would think their financial advisors would prevent them even if the banks give no resistance

akiselev• 7 years ago

If they're rich, they can afford to experience prime real estate before it's erased forever and if they're connected, they can get a bailout afterwards.

heavyset_go3• 7 years ago

They can afford to insure and rebuild homes in these areas.

flukus2• 7 years ago

I'm surprised they still grant mortgages, a lot of coastal places can't get insurance anymore, a responsible lender wouldn't grant a mortgage on an un-insurable property.

Of course government can always mandate a head in the sand approach...

Then there's the mega wealthy that can always afford a new house anyway, they'll be happy to pay for the location.

peacetreefrog• 7 years ago

All else equal, being in an area susceptible to climate change related flooding lowers value about 7% on average according to some research:

https://www.axios.com/sea-level-rise-costing-billions-in-hom...

Gibbon1• 7 years ago

One thing I learned the average life of a 30 year mortgage is around 5 years. Everyone involved is passing the hot potato to the next sucker.

Reedx• 7 years ago

Anyone know how insurance companies are reacting? That'd be interesting to watch, since they're all about risk management and have a lot of skin in the game.

symplee• 7 years ago

Crossing their fingers for the next great bailout.

dredmorbius2• 7 years ago

Insurance is definitely the point to watch.

Real estate as investment makes sense only where the risk is insurable, and increasingly that's becoming less the case. If insurers won't insure, and banks can't get bailed out, mortgages won't get made, and property values will plummet.

A recent realisation of mine is that the so-called FIRE sector (apt name...), Finance, Insurance, and Real Estate, effectively tripods itself. Finance provides the liquidity, insurance assesses and socialises risks, and real estate provides a huge share of the actual backing assets. If any one leg of that tripod starts to weaken, the entire structure is at risk.

I ran across a pretty good explainer video from the WSJ yesterday on just this topic (or at least the "it's getting harder to insure" bits), mostly addressing California and wildfire, but also mentioning Florida and coastal storms.

https://invidio.us/watch?v=7X3FmFDOiDc

Looking for a good text treatment, that's not as easy to find at the moment.

leeoniya• 7 years ago

weird how sea level rise is always used as the doomsday scenario rather than the much more serious threat of delicate ecosystems collapsing and famine that would affect everyone.

shawnb576• 7 years ago

this!

i'm finding that people - educated, thoughtful, caring people - have real trouble wrapping their heads around this threat, how serious it is, and how fast its coming.

these same people are very concerned about plastic pollution. real issue, but not civilization ending. and if we stopped the major sources tomorrow, we'd be fine. CO2 does not work this way.

i think it's because people can see and feel plastic. but they look out their window and things look...fine (apologies to california and other places where things are not fine)

ycombonator• 7 years ago

They had predicted almost a foot rise in sea level for 2020-25 in 1984. So we will see what happens. Source: https://books.google.com/books/about/Projecting_Future_Sea_L...

jefftk2• 7 years ago

Summary: elevation estimates using data from SRTM [1] are too high in built-up areas, because unlike with LIDAR data it's not able to tell the difference between "this is high ground" and "this is low ground with a building on it". Which means many coastal urban areas are more vulnerable to sea level rise than people had previously estimated.

They try to get a better estimate by building a more complex model, and calibrate it using LIDAR where that's available. This lets them say not just "things are worse than we thought" but "these specific parts of these populated areas are at risk".

[1] https://en.wikipedia.org/wiki/Shuttle_Radar_Topography_Missi...

GrumpyNl• 7 years ago

Where does this fit in? https://news.ycombinator.com/item?id=21310972

jefftk2• 7 years ago

If ice cliffs in the Antarctic won't collapse catastrophically that decreases our estimate for how quickly the sea is likely to rise, which is certainly good news!

But we're still going to get some rise, and accurate elevation modeling is important for figuring out what effects that's likely to have.

Roughly, you can think of these as two disconnected efforts: get the best estimate you can of the distribution of possible future sea levels, and get the best estimate you can of the impact of different sea levels on humanity. Your link is the former, this link is the latter.

guelo• 7 years ago

It doesn't, this paper takes into account a wide error range in their analysis.

yters• 7 years ago

Since the threat is so imminent, are there specific climate change predictions that have come true?

standardUser• 7 years ago

The sea level has risen around 5-8 inches since 1900 and the rate at which it is rising has increased over the last several decades (and continues to increase). This is compared to roughly 2000 years of stable sea levels prior to the 1900's.

lurker458• 7 years ago

One of the predictions was that we'd get stronger heat waves in West Europe. We broke several old records this year. https://www.bbc.com/news/world-europe-49100271

romaaeterna3• 7 years ago

But you've been in a warming trend for millennia in Western Europe -- the Danube and Rhine used to freeze over in the time of Tacitus.

moksly• 7 years ago

We’ve spent the last 15 years building better sewer systems all over Denmark in preparation for the increase in heavy rain falls due to climate change. We weren’t fast enough everywhere because the predictions proved conservative. Over all though it’s been a pretty big success.

roywiggins2• 7 years ago

Exxon's 1982-vintage predictions on global temperatures have mostly held up.

https://earther.gizmodo.com/exxon-predicted-2019-s-ominous-c...

baxtr• 7 years ago

Interesting article. I thought everything was good until I hit that part

The only thing its scientists got wrong was that what they called “potentially serious climate problems” wouldn’t emerge until the late 21st century. So much for that.

The linked article refers to the loss in biodiversity, which is in my opinion not really related to climate change. It’s related to the fact that we humans leave less and less physical space for other species. I think it’s wrong to combine the two effects.

ahje• 7 years ago

The ones that have come true can pretty much be summed up by "shitty weather". Shitty weather is quite capable of wreaking havoc upon human food production and infrastructure though, so the future could be quite scary even if the more alarmist reports are exaggerated.

Angostura4• 7 years ago

One prediction: We will see large amounts of ice lost from the poles, seems to have been a good prediction.

SamBam3• 7 years ago

Plenty, although "come true" depends on your definition, since the predictions are all very conservative, and the observations have tended to be worse than the predictions.

For example, the observations of the recent decline in sea ice are significantly worse than the models predict. [1]

Also, current data show the oceans are warming about 40% faster than predicted. [2]

[1] https://skepticalscience.com/graphics.php?g=35

[2] https://www.scientificamerican.com/article/oceans-are-warmin...

keymone2• 7 years ago

is there any noticeable effect of earth’s rotation and uneven gravity field on distribution of sea-level change?

chris_overseas• 7 years ago

Yes gravity, and to a lesser extent rotation, have a (somewhat unintuitive) impact on how the sea level will change across different parts of the globe. There's a good overview of this topic here: https://www.theguardian.com/environment/ng-interactive/2018/...

Edit: video showing gravity changing over time due to melt: https://blogs.agu.org/wildwildscience/2016/07/21/gravity-gre...

keymone2• 7 years ago

thanks!

nice video, seems like gibraltar is getting a lot of action

7952• 7 years ago

The sea level as it stands today is already effected by gravity. And this is in fact built into the wgs84 datum. So vertical elevation is measured relative to that assumed sea level after the effects of gravity. And a rise in sea level would presumably be measured relative to that existing datum.

auto• 7 years ago

Slightly unrelated, but first author on this paper is Scott Kulp, an acquaintance and fellow ACM member from my undergrad days, and above and beyond one of the smartest people I've ever met in my life. As in, double majored in Math and Comp Sci in undergrad, completing it in three years while looking dreadfully bored in every lecture we had together, smart.

seveneightn9ne• 7 years ago

Plug for thisplacewillbewater.com - they have a great map of what 4C warming will look like and you can also buy biodegradable stickers to post around and raise awareness if you live in an area that will be underwater.

adolph• 7 years ago

Looks like SpaceX predicts <.5C rise given their Boca Chica launch site.

https://seeing.climatecentral.org/#12/25.9917/-97.1329?show=...

https://en.wikipedia.org/wiki/SpaceX_South_Texas_Launch_Site

wolfram74• 7 years ago

Or that they'll have more than one launch site in 20 years.

tengbretson2• 7 years ago

Any chance this gets published if it somehow found the opposite to be true?

nabla93• 7 years ago

To answer your conspiratory rhetorical question: Yes it would.

There are some good news from research reported, like "Slowdown in Antarctic mass loss from solid Earth and sea-level" feedbackshttps://science.sciencemag.org/content/364/6444/eaav7908

Just because there is less good news than bad news, does not make science biased.

tengbretson2• 7 years ago

To answer your conspiratory rhetorical question: Yes it would.

The accusatory tone of your response only reinforces my concern. It doesn't even require a "conspiracy" as you gibingly added. If a scientist considering publishing findings counter to consensus expects to be met with this kind of reaction from their peers, and shouts of "denier" at large, that's all it takes to put a finger on the scale to bias what gets published.

glofish• 7 years ago

I will disagree here, science usually is quite biased! There are always lines of thinking that get into fashion, where exaggerated claims are more common.

Climate change is one of those fields.

Everybody and their little sister want to be at the forefront, and they can only get there if they either claim to the savior or become that one special person that points out yet another imminent catastrophe. It is like a 11'o clock news, nothing but bad news to get people tune in.

Just to make sure, I want clearly state that I do believe that human-induced climate change is taking place. And that we should act, reducing waste, unnecessary air travel etc.

On the other hand, how many times do we read about that there could beneficial aspects to climate change? Right now I can't recall any instance. This is what I don't buy. Every change will suck for some, it might be better for others. Talking about anything positive in the context is taboo and it is part of the scientific bias that I believe is present. makes us all weaker because we can't quite prepare for something built on exaggerations and sensationalism.

We reward those that bring us bad news.

Angostura4• 7 years ago

Are you suggesting systematic bias in climate change publication? If so, would you like to point at any evidence that this is happening?

poutine2• 7 years ago

To put this in context we're talking about 4 to 5 mm per year of sea level rise on average globally for the next several decades.

Some areas will be more and some less as sea level rise isn't uniform (for instance isostatic rebound on the west coast of Canada will result in a net sea level drop in some areas).

Mitigation will be key as even if we eliminated carbon emissions completely today there's already committed warming in the system that will result in sea level rise through the century. We're just talking about how many extra mm per year on top of the 3-4mm or so that it is now.

nabla93• 7 years ago

Map of the rebound areas https://en.wikipedia.org/wiki/File:PGR_Paulson2007_Rate_of_L...

Mainly Canada and Fennoscandia.

Gravityloss• 7 years ago

Well, who knows what will happen in the areas with massive glacier melt? Earthquakes? Isostatic rebound of the under-glascier ground? Maybe some ground will lower.

Iceberg tsunamis too.

peter303• 7 years ago

The rise has been 3 mm a year (1/8 inch) since 1990 or about 4 inches.

http://sealevel.colorado.edu/

This has been averaging millions of measurements of satellite altimeter over oceans. That is considered more accurate than tidal gauges which are subject to local changes such subsidence near river mouths.

The 3 mm is a combination of land glacier melt and water thermal expansions. I have heard talks all over the map as to which factor is more dominant.

So 4-5 mm a year in the near future is not too off.

poutine2• 7 years ago

I liked table 1 as a nice summary from a referenced paper in the above paper, found here:

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2014...

Their data suggests thermal expansion is the primary culprit.

itcrowd• 7 years ago

Here's a summary of the paper I gave before when a NYT piece covered it yesterday.

For USA and Australia, high-resolution/precision lidar-based maps are available of coastal areas. For other regions of the world it is not the case (or severely limited). However, gaining an insight into the elevation of land is crucial to determine a region's vulnerability to sea-level rise. NASA’s SRTM has almost global coverage of elevation levels, but is known to be too low resolution to be meaningful for this application (esp. in urban areas). A neural network was trained on the USA lidar data to augment the SRTM data (i.e. make the resolution higher). The network was verified on the Australian lidar dataset (and they got a good match; the model was already published elsewhere before [1]). The point of this paper was to then have the newly-derived elevation maps be exposed to sea-level change. This is where the maps with flooded cities come from [which were in the NYT article].

[1] https://www.sciencedirect.com/science/article/abs/pii/S00344...

Rising Seas Will Erase More Cities by 2050, New Research Shows

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