We looked into it when we were considering the future of my mom's summer cottage (~10 feet above sea level, ~200 yards from beach, main road floods @ 4.5 feet, been in her family since 1955). My sister's a geologist so she has access to all sorts of topological maps and climate models. Ultimately, though, the worst climate models show about 18 inches of sea level rise over the next century, so it wasn't a serious consideration. I'd be much more worried about more severe storms, but it's not in an area with significant hurricane risk.

There's a few other factors and I'd be worried about the combination of them more than any single one. Depending in location and geography and timing you can easily lose a couple of feet by an exceptionally high tide, sea level is the average of high tide marks and not the highest it can get. Even in inland areas well above sea level this can affect drainage and cause flooding. Then you've got large waves that can be whipped up by a regular storm or a hurricane, these can easily go another couple of feet above the current tide level and just standing ankle deep in water like that isn't the safest thing in the world. Then there's things like rainwater flooding that can come from inland, depending on geography and rain that can be negligible or huge.

But if the high tide and waves alone conspire then you might only have 6 feet of storm surge buffer. With an 18 inch sea level rise that's down to 4.5 feet.

Even without that erosion can do a lot of damage without expensive remediation.

Insurance companies in particular would be interesting to watch, since they're focused on risk management and have a lot of skin in the game.

How are they reacting?

Subsidized by your taxes via the National Flood Insurance Program (edit: speaking US-centrically here)

https://www.independent.org/news/article.asp?id=10524

> “The potential losses generated by NFIP have created substantial financial exposure for the federal government and U.S. taxpayers,” the U.S. Government Accountability Office concluded in a February 2013 report to Congress. “While Congress and FEMA intended that NFIP be funded with premiums collected from policyholders and not with tax dollars, the program was, by design, not actuarially sound.”

> In 2012, in an attempt to provide some financial stability to the ailing NFIP, which was $20 billion in debt at the time, Congress required FEMA to phase out many of the subsidized policies in order to more accurately reflect cost and risk. Existing policyholders naturally balked at paying the higher premiums, however, and the backlash was strong enough that politicians quickly caved and rescinded the requirements, restoring the grandfathering of subsidized policies and capping premium increases.

tl;dr: Beachfront property owners don't want to pay for their own flood insurance, so you get to pay for it instead. In October 2017 the government wrote off $16 billion of that debt, and as of February 2018 it was still in debt to the tune of $20.5 billion.

Thanks to these subsidies, people will keep rebuilding in the same idiotic places knowing that it will flood again, which is fine because you're paying for the bulk of their insurance.

I think if the insurance wasn't subsidized, the (massive) values of those beachfront properties would collapse. With that, the tax revenues derived from that would sink beneath the waves, which would bankrupt local and possibly state governments. From what I understand those subsidies are what's keeping Florida from becoming a failed state.

If that's the justification, would it would be cheaper to stop throwing the money away over and over on rebuilding in flood areas and just subsidize Florida directly?

Or would it be cheaper to stop throwing money away and let Florida become a failed state and restructure to some new stable configuration (presumably with a much lower population)?

Wouldn't other luxury housing increase in value though? It's not like the rich people are going stop having vacation homes.

If you're a beachfront town, you don't care much that rich people are now buying vacation homes in the mountains. Your economy is still ruined.

> tl;dr: Beachfront property owners don't want to pay for their own flood insurance, so you get to pay for it instead. In October 2017 the government wrote off $16 billion of that debt, and as of February 2018 it was still in debt to the tune of $20.5 billion.

The NFIP insures millions of properties, like mine, that are nowhere near a beach.

Are the premiums as artificially low in non-costal areas? I’ve been under the impression that most of our increasing flood risks over recent decades are in hurricane areas, but I do know we had pretty bad flooding in the Midwest this year too. Is that the new normal?

FEMA sent us the NFIP claim history when we bought the house, and based on the amount paid out and risk of recurrence, versus the premium we pay, I think our premium is fair. Interestingly, despite being inland in New Jersey the two claims correlate with two hurricane strikes (Floyd and Sandy). The river we are on is pretty small and only rises when there is heavy rain (and starts falling almost as soon as the rain stops).

For the house I recently purchased, it's a little over 1% of the house value every year, based on reconstruction cost and flood zone classification. Is it artificially low? I don't think so, at leaat for my circumstances.

Good question. What may happen - possibly relatively soon - is that banks will refuse to provide mortgages over a certain length of time for certain property. Property which is not mortgageable will take a serious haircut in its value. Very quickly, those properties will become “stranded assets”. What will be the likely policy response? I suspect governments might step in with insurance and guarantees. Why? Because in the Anglo world, our economies and arguably culture (ref your dinner party conversation) are organized around increases in house prices, not their collapse. Governments are always pumping house prices ever higher to inject “feel good” into the economy. The parallel is a bitcoin whale, especially in the UK.

Similar experience - I was recently at a neighborhood get-together and discussion came up around how everyone was benefiting from property price rises and considering second homes (rentals, batches/holiday homes).

It weirded me out but for a different reason: I couldn't avoid thinking about income inequality and dropping home ownership among younger generations in our country. Having a discussion about acquiring additional properties to seek rental income or to sit vacant for the majority of the year, and not factoring in that big issue, just didn't sit right with me. Not wanting to derail the mood or upset my neighbors, I just didn't actively participate. But I've been stewing on it for days since.

Back on the topic of waterfront real estate, there have been some really interesting articles linked on HN recently about Miami's situation - seemingly irrational activity happening in a city facing straight into the threat of rising ocean levels: https://popula.com/2019/04/02/heaven-or-high-water/

You don’t have to worry. The government will bail you out like they do the people who build in forest fire land and in flood plains.

EDIT: I don't think I'm wrong actually. Take Pacifica, CA for instance. Local homeowners oppose managed retreat and will ask the government to perform coastline erosion control.

And yet, elsewhere someone posted a link to an article about how three large apartment buildings have already been torn down in Pacifica. The ocean doesn't care much about city policy. Eventually it's going to be untenable to resist no matter how wealthy you are.

Oh, and we didn't pay them off via some national insurance program? I'm surprised and somewhat impressed. I'd expect those parties to have required the government to pay out.

Shoreline erosion is already concern for any waterfront property, and there are already devastating hurricanes and weather events they have to prepare for. From what I've seen, the owners of these properties are up to speed on the challenges the properties face. If there's damage, they repair it, it's just the cost of living next to the water.

In Florida, the entire first floor cannot be covered by flood insurance. Most homes do not have basements as you cannot dig down to create one. Most 1st floors of nicer homes are essentially a finished basement and posts to support the rest of the building and the main floor starts on the 2nd level.

During a hurricane, you assume everything on the first floor to be a loss so usually people may have their pools, have granite/tile flooring and do not have carpet etc so that way after a flood/hurricane it's easy to clean/fix up.

This comment sounds somewhat strange to me. If you don't mind me asking, where are/were you living in Florida where this is the case? I have lived in South Florida for 25 years, residing in areas around Martin County, Port St Lucie, West Palm Beach, and Tallahassee. Most of my vacations were spent at friends houses in Tampa, Sarasota, Fort Lauderdale, Orlando, and even Marathon Key.

Most houses I have lived in, and the houses my peers owned, were all one story houses. Those who lived in what insurances labels as "known flood zone" areas still had carpet, and the houses are decorated no differently than the houses I have seen in California when I lived there, as well as Michigan where I currently live.

We also were able to enroll in flood insurance without any issues. Granted, it's extra insurance on top of typical home owners insurance, but Allstate had no issues providing us with flood insurance for over two decades of living there.

Is this perhaps how the more wealthy people live, or is this maybe how a specific area lives? I have legitimately never heard of people purposely furnishing their first floor as if it were a basement. I have seen the trend of moving away from carpet, but that is a more general trend that I am observing here in MI, as well, so I am not entirely sure it is can be directly linked to home owners worrying about potential flooding.

It was in a more affluent area of Ft. Myers where most homes were north of $750k on canals that go to the gulf. I apologize for not responding earlier, usually after 3-4 posts I end up being throttled where it says, "You are posting too much please slow down" and then I have to wait until the next day.

The point about insurance is not accurate. In some low-lying areas, these statements are accurate, but even in coastal areas it is far more common to have a finished 1st floor with the standard insurance rules. It all depends on the flood/evacuation zones.

That sounds like a smart way to engineer homes in flood prone areas.

Alternatively, don’t live in Florida.

Also this only applied in an area along the Gulf Coast, if you live further inland you may be able to get insurance that covers the first floor, but I have no idea.

I do agree though, I like to visit Florida here and there but I would never want to live there permanently.

This has become standard fare up and down the East Coast.

I think shoreline erosion is a good example of what will happen.

An apartment building just south of SF was recently condemned and torn down because the cliff it sits on is slowly falling into the ocean.[1]

[1]https://www.latimes.com/local/lanow/la-me-ln-pacifica-apartm...

The sea level rise is slow enough, at less than 1cm per year projected average to 2100, that it doesn't have a material affect on your decision, unless the land is freakishly flat and low (like a sand atoll somewhere) So respectfully, I think your aversion is more emotional than logical.

Lots of emotional down-voting going on. I'm still right.

Please don't break the site guidelines by going on about downvotes: https://news.ycombinator.com/newsguidelines.html.

(Secondarily: language like "your aversion is more emotional than logical" is best avoided on HN too. I appreciate your intention to be respectful, but it's still a gratuitously personal comment. If you converted it to an actually respectful expression of the point, you wouldn't need to label it "respectfully".)

It's a statement of fact, if my reasoning holds. I agree I could have made my point without making it personal though. It's offensive in the same manner as saying your religion is a lie (also a statement of fact, but not one that will win any friends.)

Yes, it will be slow. My family has a guest house on the beach. It's on short (5 ft) hill about 30 ft back from the ocean. The back sits on the hill and the front is help up by support beams. The yard is barely (1-2ft) above the average high tide mark. I was visiting during a storm and was in the guest house looking out of the window and it dawned on me that if (when) we get a bad-enough storm during a high-neap-tide, the support beams holding up the front room be washed ou. It would only be partial damage, and most people would probably consider it a "once in a 100 year storm", so I'm sure the damage would be repaired. With sea level rise, a 1:100 year storm will quickly become more like 1:50 or less, then 1:20, then 1:10, etc. At some point, we (or future owners) will give up rebuilding. If you only want a small get-away cottage on the water, then I'm sure sea level rise will be slow enough that you'll be fine. If you want a home on the water that you can pass onto your kids or grand-kids as a family investment, then I'd stay away.... or at least, consider the geology/topography/distance to the water.

That’s not how it works. That’s why you are getting downvoted.

Firstly the rise is not the same everywhere - some places will have vastly higher sea levels. Secondly Venice didn’t suddenly get flooded by going from from 0cm too high to 1cm too high this year; the issue with climate change is not just the level but also the highs from more energetic, wetter storms etc.

No, I'm still right. It is true some places will have more rise, but also some places will have lower rise. Also storms are not getting noticeably stronger either, that's just as slow. Really you can buy ocean front property, and the concerns are more to do with local tides and weather and topography than anything to do with climate change. Cost will still be the primary concern, beachfront property is not cheap. The local issues dwarf climate change to the point that it likely doesn't even feature in your final decision, if you're being logical and not emotional.

In my work with climate data, scientists in my cohort are instructing caution that many (linear) models are incorrect, and those are the figures you quote (1cm/year sea-level rise). However, not only have past sea-level rise projections been incorrectly low(1), but tropical storms/hurricanes have become measurably more frequent, more powerful, and slower(2), which also causes increased flooding. So, even if your beachfront property is not at increased risk from sea level rise, there is an increased risk of flooding and storm-surge exposure (in some places).

When I was attempting to establish historical storm trends for the Florida Keys in the early 18th century (for an archaeological study), one colleague suggested I not use post-2004 data, because the warming of the oceans was skewing everything from mean wind directions to the number of hurricanes to the current patterns. The costs associated with beachfront property are also rising, due to the insurance industry's discomfort with the risks and the additional maintenance costs(3). Even the US's National Flood Insurance Program is increasing the charges of its subsidized coastal insurance products(4), because private industry deems many coastal properties uninsurable.

So, I gotta ask: On what data are you basing your opinions?

1) https://www.nature.com/articles/s41467-019-12808-z 2) https://www.theguardian.com/weather/ng-interactive/2018/sep/... 3) https://www.allpropertymanagement.com/blog/post/what-climate... 4) https://www.gulfshoreinsurance.com/summary-of-nfip-program-c...

I'm looking at the same data as you, and agree with your points. It's possible sea level could rise faster, but even at worst case protections climate change probably doesn't make the top ten factors when considering a specific property.

If the property is so vulnerable to rising sea levels or storm surge, it is going to be vulnerable with and without climate change. Climate change itself doesn't seem to change the calculus much.

In financial markets, expectations of future gain and loss impacts pricing today.

In exactly the same manner expectations that the future value of real estate may be impacted by climate change should be reflected in the price today. Even if the house I buy today does not flood in 20 years (my lifetime), in 20 years I will have to sell to someone who will have an investment horizon of 40 years from today (my 20 years, plus their hypothetical 20 years). Since that person may demand a lower price from me in 20 years, I should factor that into the price I pay today, since it effects my returns.

As a real example, I factored in expected flood insurance pricing rises on some riverfront property I purchased recently in Australia. The insurance price increases are driven by industry and government modelling to reflect tropical storm intensity and frequency and an increased risk that storm surges overlap high tides. Sea level rises contribute to the risk, but not in a meaningful level.

The end result was that my total cost of ownership increased by single digit %. I reduced my bid price accordingly to meet my % return requirement from the investment.

To put it concretely - my future expectation of increased climate-driven risk reduced the value of the asset to me.

Your confidence is misplaced, and your condescension is irksome.

Your confidence is misplaced. For example, improving the reliability of measurement indicates storms are in fact getting stronger. https://www.pnas.org/content/early/2019/11/05/1912277116

That's in terms of damage, not strength. Huge difference, depending on what we build and where. Although I'm not denying storms are getting stronger, it's slowly, just like sea level rise.

I wouldn't buy waterfront property in Florida, but mostly for the problems inherit with doing that today, not because of future climate change.

A difference of even 2 feet makes a difference across huge swaths of US beachfront property. A storm surges can get up to 34.8 feet at current sea levels. Moving that to 36.8 would both more frequently destroy structures within 35’ of sea level, and B put massive numbers of new buildings at risk.

Right, the rising average sea AND the rising weather/atmospheric energy combine to make formerly rare flooding events more common.

Eg Wall Street flooded during Sandy.

You just classified the difference in storm surge as 6%. That is too small to be a defining part of your final decision.

People want to build as close to the ocean as they can, they also want to build in a safety factors After all that 34.8’ is the highest level ever recorded. Is 30’ is good enough how about 25’? And when you go down that road it gets very non linear with 10’ being almost worthless and 40’ near total protection from storm surges.

Thus it’s not a question of absolute levels, but rather safety factors and insurance premiums that are at issue.

PS: Though this is simplified as it’s both storm surge and high waves that cause problems, but that’s another story.

If you're making any decision with only 6% tolerances on one side and vague things like storms and tides on the other, you're in trouble.

I just don't see that as making the difference in a decision to buy or not buy. I don't even see it making the list of things to weigh.

Ahh, you’re still thinking if that as 6%. Hatteras NC is 50 miles long generally less than a mile wide and the absolutely highest point is 56’ above sea level. More topically for these islands Nags Head, North Carolina averages 3’ above sea level at high tide. People build everything on stilts and It’s simply accepted that it’s all temporary at some level.

As the barrier islands essentially make up the only beach front property across half of North Carolina, that’s the only real option for vacation homes like this. That and fishing support a relatively small population, but the total investment on these islands adds into the billions.

In that context 2’ means far more than a 6% difference. Little there can withstand a cat 4+ hurricane even without the ocean, however slowly loosing inches is already making a difference.

Well 2ft of 3ft is no longer 6%, that's a material difference that matters if you want to buy there.

What I would consider is what it would cost to raise the land by that 2ft. I think that's so little by comparison to what the land costs that you can practically discount the effect of climate change on your decision.

People hated on all of my comments in this entire thread, but at the end of the day I put my faith in the math and I think they're all wrong and I'm right.

You're not right. You have neglected to consider the impact of tides, because the 1cm rise in average sea level is not evenly distributed.

Which means it also has to be less in some places, and those places would be slightly more attractive. So use that projected tidal value if you want when weighing your decision. Factor in stronger storms if you want as well.

Ocean front property is so expensive that if you do that and add the cost of raising your construction on stilts and/or raising the land to compensate, it barely makes a difference.

Not much it seems

https://twitter.com/evankirstel/status/1164575263293956096