The California coast is disappearing under the rising sea | Hacker News Reader

The California coast is disappearing under the rising sea

latimes.com

Macro trends in nature are strong, humans can try and mitigate but we’re ultimately takers on the trend. There might be cases where sea walls provide compelling protection along specific parts of the coast, but as a grand plan to save the existing coastline, it’s a waste.

We studied Pacifia’s cliff side/coastline degradation in hydrology class. What’s happening is that waves erode the bottom of the cliff and the rest sloughs off, like pulling Jenga blocks from the bottom of the pile. A massive sea wall could slow the rate of cliffside erosion on the time scale of a generation, But the risk/hazard will remain. I don’t see the the benefit to society for not retreating development here.

No.

We created almost all of this - the increase in global sea level due to melting ice caps and glaciers is entirely on us. Similarly the increase in energy in the global weather systems is driven by the same source, and causes the increases in "extreme" weather, which further drives accelerated erosion of coastal regions, flooding, and droughts.

We can try to slow down the damage caused by the symptoms, and as you say, that's all we can do, but it's super important to acknowledge that humans do override "macro" trends in nature. The problem is how we undo changes we caused. Short of magically coming up with a way to dramatically remove heat from the oceans and atmosphere we are at best stuck where we are. Given we haven't made any meaningful changes in the industries causing the climate change we can't expect anything more than further acceleration of the extremes.

Even at a constant sea level we still have wave erosion.

Geoengineering on the local scale of building sea walls to prevent cliffside erosion will almost certainly be far too expensive to justify the benefits or time it buys before the inevitable happens.

This isn’t just about global warming. It’s about the power of the ocean, possibly with increased power from the effects of global warming, tearing down a town built on a cliff.

The discussion in the article is about people building on pretty real estate that’s dangerous to inhabit, and asking the government to preserve it.

I remember studying this in high school geography.

There's a part of the east coast of England that's being eroded at a rate of a couple of metres per year due to the sea cliffs being made up of soft glacial deposits.

It's an interesting example because people can observe the effect of the sea eating the land in a very short time. Some losing homes that were once miles from the coast.

Of course this phenomenon occurs on every coastline, but it takes generations.

https://urbanrim.org.uk/Holderness.htm

A good friend used to rent a house overlooking the ocean in Pacifica. That was 2000, and that house is gone now. Amusingly, she lives in Manhattan now, and might get to see Chapter 2 or 3 of this epic saga we are living through. My kids will hopefully get to the end of the first book, if we get lucky and avoid a serious war somewhere in the middle. We moved from 8’ above sea level to 700’ above sea level last year. I still expect to help pay for saving the SF Bay Area, which will actually be able to engineer its way out of this thanks to a combination of fortuitous geographical circumstances and an economy large enough to sustain the trillion dollars it will cost to protect the area.

Ocean Beach will be history soon enough, though...

I've lived in the bay area for over 25 years and Ocean Beach has always remained exactly the same. Pacifica has had serious cliff erosion problems for as long as I can remember. huge problem in California is building in places that shouldn't be built on - fire plains, cliff tops etc

The reason Ocean Beach has always remained exactly the same is that the city relocates thousands of tons of sand to south end of it every year.

The city moves the wind sand drifts yes, but the tidal flows in and out of the golden gate are moving incredible amounts of sand pretty well every day, which is why the high surf moves around so much. It's not as though SF engineering is pushing sand south with bulldozers every year after it piles up near the golden gate bridge. There is way to much drama and misinformation flowing around on this topic IMO

It's hard to imagine SF being affected by this that much anytime soon. I can imagine the Marina and places like that having issues, but SF itself is so tall and there's so much hard rock everywhere.

But I don't know much about the Sunset or the Richmond so I guess you could speak better to that. I live near Twin Peaks.

Decently sized chunks of SF used to be water. https://en.wikipedia.org/wiki/Mission_Bay,_San_Francisco

Edit: elsewhere in the thread there’s a nice link to a map from the US coast survey, https://upload.wikimedia.org/wikipedia/commons/9/9d/1858_U.S...

Marshland and lagoons sounds a bit different than ocean, though. Would they not be easier to drain and contain? Or are you saying this past makes it more susceptible to bay/ocean encroachment in the future?

I'm no civil engineer so this is totally out of my realm of knowledge.

Also, I guess I'm lucky to live on one of the highest points in the city.

I don't know what a "fire plain" is. But would you consider Oakland being in one? https://en.wikipedia.org/wiki/Oakland_firestorm_of_1991

The fire problem in California is basically anywhere there is any wilderness. The state inevitably gets dry and becomes a tinderbox.

Same as a flood plain, an area that has seasonal conditions that are likely to endanger the area. Example: The recent Santa rosa fires which took out Fountaingrove. An identical fire happened same time of year and wind conditions in 1968 when the area was mostly grassland. They are already rebuilding huge houses there after the recent fire.

For most who do not own a home near a shore or in a flood plain, the answer is obvious, and the game reinforces this (it only allows this as a long term success) - do not attempt to change the advance of rising sea levels at sandy beaches and buy back the threatened homes for a managed retreat, every other option essentially is short term stop gap solution for the threatened home owners.

To play devil's advocate a little, why should those homes be bought back?

they shouldn't be. But then I believe Texas ruled that requiring realtor/home-sellers to report that a property was on a known flood-plain was the government "taking property" (because requiring realtor to say the house will flood decreases sale value) and therefore illegal.

Because it's the job of the country/state to decide what land are safe to be built on.

If building too close to the shore was a bad idea, and it was known at the time, the zoning should have forbid it to start with.

These people are not personally responsible for the raise of the sea level, it makes sense to have the risk taken away from them.

> Because it's the job of the country/state to decide what land are safe to be built on.

Not everyone agrees with you. Personally, I don’t think it’s up to the government to tell you where you can / can’t live on land you purchase. However, inspections should and do occur informing you of risks.

Zoning has to do with a variety of factors, but I doubt for most of U.S. history it had to do with “will this coast erode in 100 years” From my limited understanding it has more to do with what CAN be built, not what SHOULD. Basically, “this can be commercial real estate because we need revenue/jobs” vs “this can be residential because we need people”

> Personally, I don’t think it’s up to the government to tell you where you can / can’t live on land you purchase.

I respect your opinion, but isn’t it the very purpose of zoning to define what can and cannot be done on that purchased land ?

And it’s already used for protection of habitations, for instance not allowing houses in industrial areas. For high risk areas, this all issue could have been avoided by refusing building permits as well, but blanket deciding a whole area can’t be used for living is the easiest course of action IMO.

I think we see the reasoning a bit in the current flood insurance program in the United States, the federal backup insurance plan has become the sole insurance plan for a lot of homes built in areas where there were flood plains in the past or are now in flood plains due to climate change or our past definition of 100 year flood plain (used for pooling into requiring flood insurance) was not a good measure. The home owners do not want to move and will not accept a buyout at a realistic price, and we get homes in flood plains getting rebuilt 10 and even 20 times. https://www.wsj.com/articles/one-house-22-floods-repeated-cl...

For those interested in data from the World Meteorological Organization (WMO 1233) Published by: WMO ; 2019

"Over the period January 1993 to December 2018, the average rate of rise was 3.15 ± 0.3 mm yr-1, while the estimated acceleration was 0.1 mm yr-2. "

https://library.wmo.int/doc_num.php?explnum_id=5789

There are of course debates relating to the well-known discrepancy between land-based and satellite observations of sea level rise.

Why are you all responding as if the information in this article is true? It's obviously false to anyone who has been to the same beach for the last 30 years. Have you all lost your minds? Have your eyes stopped working? GO LOOK FOR YOURSELVES.

Go watch the compelling video from Tony Heller regarding this article.

I thought my friends on Hacker News were smarter than this

If the Netherlands managed to reclaim land through dikes. Why couldn't California do the same in their coastal affluent neighborhoods? California doesn't get bad storms and it rarely gets a hurricanes / tornadoes / tsunamis...etc.

For the bay area...Why not just drain the bay. There was a proposal previously and cost wise it'd easily pay off given the land gains. Heck could easily solve our housing and transit issues

There are large wildlife preservation efforts in the Bay Area marshlands (particularly near shoreline park) that would be destroyed.

They'll be destroyed by rising sea levels eventually anyway.

Then just damn up the entrance to the bay and control it's water level. Same risk as draining the bay all together.

Either way global warming is going to change the landscape. Might as well attempt something that limits damage

That's close to literally impossible.

There was an absurd plan to place a dam between Richmond and San Rafael[1]. When it was finally studied, there were two fatal problems with the plan. (1) There is not enough water in Summer, to keep the bay behind the dam full. (2) There is too much water from snowmelt in early spring and the San Joaquin valley would turn into a lake.

Now to the environmental side: the bay is amazingly productive. It also acts as a nursery for the ocean. The damage done to the Pacific Ocean ecosystem would be all out of proportion to the gains of a little bit of land.

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

The Netherlands drained their below-sea-level land at a time before widespread environmental studies and other sources of outside interference. California is notorious for some-random-group-or-another interfering with building plans because it would destroy the homes of the San Elijo Grey-billed Duck Platypus or whatever

No, the Netherlands "solved" the problem because they've experienced one flood too many. The more obvious the problem is to an average citizen, the easier it is to gather enough of support to actually tackle it.

This is totally different because it's gradual. Humans aren't good at thinking long-term, so it's more difficult to gather the support for projects that benefit us in the long run. The glaciers are melting, the seas are rising, but a congressman brought a snowball to congress so we don't have to do shit that inconveniences us now for something that benefits us in the long run.

They still lacked the kind of environmental-activist interference that plagues California projects; few if none of these groups existed back then or had the ability to manifest any kind of political power

> Why not just drain the bay.

San Francisco exists at all because there is a bay there.

Why would SF go away without a bay? Do you mean because of tourism?

If anything it seems like SF would grow its boundaries if this happened.

Along with LA/Long Beach, Oakland is one of the two major ports on the US west coast. It does tremendous amounts of shipping.

Trains, planes, and automobiles would surely still function?

Is there something inherently better about seafaring ships? Wouldn't the ports just move?

The Nederlands indeed does this and there is no talk of gradual retreat. We are too invested in the current system, retreating means relocating 7 million people and the economic heart of the country. So we built mega walls. No one really knows how much and how fast sea level will rise. The guesstimates vary wildly. So far, the last century sea levels increased very moderately.

Hi Joel, there is talk of gradual retreat by the experts. This was published in popular Dutch magazine (and perhaps talked about in talk shows, but I don't watch them), it was also published on the NOS site (the national news). Here is a translation from the VrijNederland page: Rolf Schuttenhelm. De zeespiegelstijging is een groter probleem dan we denken. En Nederland heeft geen plan B. 9 februari 2019.

We need to consider controlled withdrawal in due course,' says polar meteorologist Michiel van den Broeke of the Institute for Marine and Atmospheric Research (IMAU) at Utrecht University. He emphasises that there are great uncertainties when it comes to the loss of ice in Antarctica, for example. This is even smaller now than in Greenland, but the ice loss has tripled in the past ten years. Will this acceleration continue?

Van den Broeke received the support of his Utrecht colleague Roderik van de Wal: 'The enormous long-term effects are usually neglected. There is a strong attitude in the Netherlands that we will solve the problems with adaptation. That's a misconception.

Glaciologist and climate change teacher Michiel Helsen also calls for a social discussion: 'Is living below sea level still responsible? In the long run, it is possible that we will not be able to preserve the western part of the Netherlands. I think it would be useful for society to discuss which parts of the Netherlands we want to defend at what price.'.

Van de Wal: 'If we continue like this, a large part of the Netherlands will have to be abandoned. Moving to Germany should be a topic of discussion. At some point there will be no turning back. And within ten or twenty years, we will be able to conclude that this point has been passed'.

Also see: Heleen Ekker. Kustlijn opgeven en het hogerop zoeken, dat is een plan B bij zeespiegelstijging. 9 februari. https://nos.nl/artikel/2271163-kustlijn-opgeven-en-het-hoger...

And 'Als Nederland onderloopt..' https://www.vn.nl/als-nederland-onderloopt-andere-problemen/

Yes, I know about this. I wasn't accurate: let's say there is no practical talk or any actual government plan for retreat. The real estate market here is hotter than ever. More metros, airports and houses are being planned and built in the Randstad (that's the area that's under sea levels and the most important economic part of the land). Some experts think gradual retreat needs to be thought about, while many others think we can solve it by other means, or simply wait and see to get a feel for the sea level rise pace (which I think is the ideal way. we simply don't know enough yet). I'm taking an unpopular opinion here I guess but I just don't think we know enough to panic... I think the chance the Randstad would be evacuated in the next 50 - 100 years is about similar to the chance San Francisco would be evacuated; close to zero. Too much real estate, infrastructure, and historical treasures lie in these cities (think about Amsterdam for example). Even a massive sea dyke that costs about 80 billion euro, that would become a second coast for the Netherlands and could withhold 2-3 meter sea level rise, will be tried and built before you evacuate a trillion dollar worth of infrastructure.

Draining the bay is probably too extreme, but much of SF is already built on reclaimed land. All of Embarcadero, Mission Bay, Southbeach, even parts of Rincon Hill were underwater in the 1800s: https://upload.wikimedia.org/wikipedia/commons/9/9d/1858_U.S...

If you drained the bay you’d lose one of the most important ports on the west coast and basically all heavy industry in Northern California

Not mentioned at all are the big winners, at least for a time, of managed retreat: Owners of the properties just inland, who suddenly acquire whitewater views. These can now charge rent to vacationers at some multiple of what was formerly possible.

Admittedly it's a bit of a puzzle how in practice either their former seaward neighbors, or the public, could lay claim to a share of that increase in value.

Let me preface this by stipulating that I believe the evidence that humans have contributed to a warming climate in the last few centuries with all of our carbon emissions, primarily from energy production. I'll further add that it's entirely possible and even quite likely that we are in and have either caused or massively contributed to a mass extinction event.

That being said, I really wonder at the thinking of what I would call "climate alarmists". I mean the Pacifica cliffs are a story about erosion. Ok, sure.

But some like to push this narrative that unless we drastically do something the Earth will turn into Venus, basically.

Thing is, these "boy who cried wolf" type narratives don't really help change perceptions or habits around climate change. What's more, they don't really pass the smell test.

The Earth has been around for billions of years. It's also been much hotter than it is now (eg [1]). The smell test is basically this: a lot can happen in 5B years and if the Earth has been much hotter than it is now and it hasn't turned into Venus yet, why is now different?

There's actually a pretty natural limit to how much carbon we can add to the atmosphere. Eventually we'll just run out of fossil fuels, at which point, we'll just start making them out of thin air and that, by definition, will be carbon neutral.

Honestly I just don't believe we'll fundamentally change human nature here. While that might be fatalistic, even pessimistic, personally I'm optimistic. And I'm optimistic because with not much more automation than we already have the Earth can grow enough food for 10 times as many people as we have now and possibly much more than that and that everything changes once we get sufficiently cheap energy (and obviously I'm optimistic about that happening in the not too distant future). Some here will write that off as naive futurism. Whatever.

With regards to sea level rise, let me add some more context. Over the span of ~5000 years 9000 to 14000 thousand years ago the sea levels rose SIXTY METERS [2]. And we're still here. That's also a blip on the timeline of Earth's geological history.

Whose to say the sea levels won't recede with the next Ice Age? Or are we now arguing the Earth is done with those too?

[1] https://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Therm...

[2] https://en.wikipedia.org/wiki/Early_Holocene_sea_level_rise

'...the evidence that humans have contributed to a warming climate in the last few centuries with all of our carbon emissions, primarily from energy production' What is this evidence exactly? I"m on the fence about human contributions to changes in earth weather and suspicious about carbon taxation. Sensible stewardship of the planet is a no brainer, but the hysteria is slowly increasing with children particularly freaking out about the planets demise after daily doses of alarmist rhetoric. This can't be healthy and pushes people to go along with questionable political measures. We are at a point where 'climate change' by human activity has to be pushed by Greta Thunberg and others as a slightly fanatical emotional event. I'm not seeing nearly enough hard evidence despite the legions of angry people I come up against who assure me 'it's all been proven' and claiming I am anti science...

> hysteria is slowly increasing with children particularly freaking out

Could it be because they're exactly the ones who will suffer from this?

The history of CO2 levels in the atmosphere [1] is a good starting point unless you're arguing that adding CO2 to the atmosphere does not and will not cause warming, which would be a bold position to take.

And why do you even care what some Swedish teenager I'd never heard of until right now is protesting climate change? Why does that matter?

[1] https://climate.nasa.gov/climate_resources/24/graphic-the-re...

It's a heretical position to take against popular opinion and beliefs that adding CO2 to the atmosphere does not and will not cause warming, but the evidence is by no means absolute. http://www.petitionproject.org I care about the Swedish teenager because she's been nominated for the Nobel prize and has dominated popular opinions this year. Daniil Gorbatenko wrote a good piece on her, I found a link to that here https://fee.org/articles/the-real-problem-with-greta-thunber...

There is an awful lot of human suffering on the scale between current earth conditions, and "venus", which you seem oddly focused on. Venus is a wildly different environment to Earth, several hundreds of degrees hotter. The people you incorrectly called "climate alarmists" are scientists talking about conservative estimates of single-digit degree warming over a century. Smell test based on intuition don't really cut it.

It's also worth acknowledging that Earth has had very different climates in the past. Sure, we can celebrate the fact that our sparse nomadic ancestors survived and adapted through gradual environmental change. That tells us almost nothing about the ability of our globe spanning, voraciously energy hungry, WMD-wielding civiliation's ability to do the same of much, much shorter time frames.

I don't quite understand the "well Earth will be fine" form of denialism. Sure, Earth would survive a total nuclear war over geological timeframes too. That doesn't really mean anything to humans as an advanced society that plans to stick around for more than a few hundred years.

“The earth will be fine” is our generation’s “let them eat cake.”

There are homes right on the edge in Pacifica. You walk out of your backyard and to the cliff. I can't wait for us to bail out these people.

The ocean is literally inundating your town, and you're worried about home values and 30-year-mortgages? These people all need some kind of loss and grief counseling. Can't wait for the federal bailout money to start pouring into these areas over the next few decades as localities deny and delay until they have no choice but to up and relocate in a hurry.

Federal money has been plowing into many of these regions for years. Guaranteed loans and insurance are entirely tax payer funded subsidies/payouts to people who aren't willing to move to areas that don't get flooded/washed out every few years.

I recall John Oliver having a segment on it at some point - basically a bunch of areas in Florida and the South get wiped out repeatedly but the federal support means they're not moving, and some of the same houses have been wiped out multiple times, and are still getting federal support to be rebuilt in the same place.

Also that federal support comes without any funding to make the house more weather-ready for the next storm.

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