A Louisiana gas plant sea wall shows challenges of flooding, energy demand
washingtonpost.com
washingtonpost.com
The problem with those "once-in-500 years" figures is that they are based on historical data - and climate change is rapidly invalidating that data. Climate change doesn't mean it's 1.5°C warmer year-round, or the sea level is 20cm higher worldwide: it means weather becomes more more extreme. What was a "once-in-500" event a few decades ago might turn into a "once-in-25" event a few years from now. We are already noticing those changes in day-to-day life!
There are well established probability distributions for these things, so you're really just solving for which published curve and maybe a magnitude multiplier and seeing where your data fits.
Also there's uncertainty baked-in and accounted for at every step of the engineering design process.
Eg. Geotechnical engineers love to calculate 6 digits to 4 decimals then throw in a 400% factor of safety.
Not to worry, that was taken into account when they came up with the 500-year naming scheme.
Sure it sounds like 500 consecutive years, but it's really a 1 in 500 chance of absolute devastation every year.
How bad was the devastation?
Approximately 5x as bad as the ones where it's only a 1 in 100 chance of striking every year, naturally.
Those of us who understand probabilities immediately recognise that even assuming the base-line probabilities are correct, this will occur far more frequently than once in 100 years.[2]
And of course, the probabilities require a known historical distribution, which itself changes over time (climate change being only one of multiple factors). It is possible to make inferences based on the observed rate vs. intensity or magnitude of events. In many cases these follow an inverse-log relation, such that order-of-magnitude greater intensity events occur with an order of magnitude less frequency. Tracking the more-frequent, lower-intensity incidents actually gives a good proxy for how often higher-intensity events will occur.[3]
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Notes:
1. "The 100-Year Flood" <https://www.usgs.gov/special-topics/water-science-school/sci...>
2. A 1% probability event has a 99% probability of not occurring. For a period of time, raise 0.99 to the power of the periods occuring. Over a 100 year period, that's 0.99^100, or a 63.4% chance of no such events occurring. For the probability of k occurrences over n periods you'd apply the binomial distribution: <https://en.wikipedia.org/wiki/Binomial_distribution>.
3. This is a relationship which applies to a whole host of events, and is very frequently observed in general physical phenomena. Asteroid impacts, earthquake intensities, volcanic eruptions, storms, wildfires, terrorist attacks, and the like.
Climate change effects are already being included when calculating wind and wave loading in many codes.
The real issue is that engineering codes use frequentist methods which make it hard to consider uncertainty, which often makes it unclear what the real safety factors are. This issue is being solved by using probabilistic engineering techniques, and in future, more sophisticated causal inference.
Adjusting how you call the storm doesn't make the wall bigger: that's the problem. (It also makes their statement untrue in the present day, regardless of if it was true when the wall was designed.)
It's the engineer defining his design criteria (the 'design-storm'), based-on and benchmarked-to local historical data, including recurrent intervals.
The wall doesn't need to be bigger if next years data changes. It was designed for a (this year) 100yr- or 500yr-storm, not a guess of hypothetical future one.
Those thresholds and definitions are based on the data record, and already encoded into regulation and a 100 years of construction.
What we see instead is Regulators simply increasing the requirements from a X year storm to a 2X year storm, and leaving the definitions. This is what I have seen with the California building code
Assuming that designing for a 500-yr storm has anything to do with 'predicting what a 'future 500-yr storm' (or 25-yr or 100-yr) looks like is dead wrong. Irrelevant.
The 'definitions' are not left alone, they are updated as time goes on. But with historical data, and they are not extrapolated/predicted out into the future.
Engineers (PEs) design by taking known criteria and then applying probabilities and factors. They do not predict criteria. It's a subtle but important distinction.
A 500yr event, by definition, is actually the one year probability of a 1/500 chance event.
And it's up to the designing engineer to choose and state whatever the assumptions are that go into that.
But a levee designed this year will use this years current 'storm definition' just as it uses this year's building code. Not a future one.
(Sometimes the storm/ event definitions seem stale because things like flood maps might only get updated every few decades.)
1 in 500 year storm is a one-year probability of 1/500, based on now.
There is no implied or expected future change that needs to be considered. That's already baked into selecting the design-storm-interval of 1 in 500 vs 1/250 or whatever else.
A 1 in 1000 year event need not be, and likely won't be, the same/valid probability in the year 3024. Or even 2074. And that's OK. The engineers know that.
Rule of thumb is usually 30 yrs minimum of records/data from usgs/ nws or similar weather stations. But it's often less.
Then it's just a probability eqn, and there are various rules for making adjustments based on things like distance away from the weather gages.
But the more fundamental thing is you are setting a static design benchmark, not a future or perpetual target.
Once that benchmark is set, you apply factors/probabilities of various failure modes.
Or you can just choose a larger design-storm.
But you don't say 'I'm designing for what the 2025 or 2074 or 2124 100-yr storm will be'.
It's more likely to be based on historical data that as of now is outdated and unreliable
It cannot be 'outdated and unreliable' (due to future expectations), because that's not how it's defined.
And it's not how engineering design processes work. (Google LRFD or ASD)
'Now' means the historical data that is current as of design.
You are merely setting a design criteria benchmark. Based on historical data.
If you want to account for future uncertainty, it goes into the other side of the design equations, via the factors and probabilities.
But more fundamentally, picking a 1/500 design storm already takes into account certain aspects of risk levels, and has nothing to do with expected lifetime or survivability. You can and do often pick design storm intervals that greatly exceed design-lifetime, for various reasons.
A "100 year flood" implies there's a 1-.99^30 or a 26% chance of happening over the life of a mortgage.
I always feel like if it were phrased in that way people would grasp the concept better. Same idea holds for any X and Y.
Obvious who knows probability and who's a PE, plus various levels of self-awareness. Otherwise intelligent ppl taking terms at face value that are actually terms-of-art / industry lingo. And sometimes grossly misapplying such terms.
And that's before you even get into politics/ ideology, should you want to judge such things.
It's a 6d personality/intelligence grid.
Throwing 100 interviewees into a hypothetical thread like this is the closest I can think of to the perfect early round hiring process.
There are non-earthen levees in the city as well. For instance in the 9th ward. These are the levees that failed during Katrina. It’s the Army Corps of Engineers that constructs these levees and have become more complex (better?) over time; imagine an upside-down “T” structure buried in the ground.
If I had to guess, I suppose the reason may be that it’s because they’re outside the protection zone, and so, when it floods (not if) their infrastructure would be surrounded regardless. Also, a concrete structure surrounding only their plant I assume is orders of magnitude cheaper than moving the amount of earth it would take to build 100+ miles of earthen levees.
[0]: https://commons.wikimedia.org/wiki/File:Venice,_Southernmost...
It takes nearly a day to crawl up the river M from the Gulf of Mexico. A 18 deck monster at around 180,000 tonnes has to take it easy to avoid damaging the levees with its wash, scouring out the river bed etc. At one point, over the course of 45 minutes, our captain decided to overtake a tanker (showboating). A few minutes later we had to park up in a herringbone formation to wait our turn to dock, which took several hours.
I think it is around 70-80 miles from the sea to NOLA. From 18 storeys up a river as huge as the Mississippi still looks huge. The levees don't look very large though from up there though, they look very flat and fragile.
I studied Civil Engineering in Plymouth (Devon, not MA) and that trip on a cruise ship gave me quite a perspective on engineering works and nature.
@pjot - if you get a chance, take a run up the Mississippi on a really big ship. Its quite an eye opener.
Fun fact, a ships captain is not the one piloting the boat, they instead must relinquish all control to specialized Mississippi River pilots at the mouth of the river.
All ports and many transits require a Pilot.
There isn't a single reason for RC, but the biggest reason is that our local soil sucks and good soil to make 'well-engineered' earth structures is a limited resource.
Additionally, there's differences in engineering philosophy between public-works and the oil field (I do both), and it's probably the opposite of what most think. Especially wrt capitalization/ finance. Almost nothing is done cheapest, let alone cheap in the coastal oil field.
Oil wants it done for a known cost, even if higher up front, to have higher certainty in long-term risk/ or lower maintenance costs. (Also soil takes months longer to settle, and time might be big money, depending on the project.)
If that higher cost tanks the project numbers, fine; they have 100 other projects lined up to make that IRR without resorting cost/corner-cutting.
Other thoughts:
Stone that is suitable for armoring earthen structures isn't sourced locally. No mountains. Has to all be barged in.
And still wouldn't survive the constant battering of wind/waves (in both a long-term seasonal sense, as well as during an acute storm event) as well as concrete.
Subsidence of a pile supported concrete structure will match the adjacent pile supported facilities, and be minimal compared to an earthen structure, which will also have expected settling on top of subsidence.
Floodwalls can double as containment berms, and that adds many design considerations not typical for stand-alone flood structures, including chemical resistance and fire suppression.
But even something as simple as grass cutting might tip the scales. Lots of heli- or boat-only access facilities, and grass needs to be cut at least once per week during summer here. Maintaining grass/earth isn't necessarily cheaper when your yard guy needs a stack of govt twic/osha cards, a private ferry ride out, and probably transport to a private dock a few hours from town.
All of which just barely gets into the logistics involved in the industry.
>more likely to fail catastrophically
Maybe catastrophically, depending on how you want to define it, but less likely to fail overall. Concrete is more likely to fail in a predictable manor.
Even the Katrina concrete/steel 'floodwall' failures were actually soil failures, not RC or steel ones.
Even though soil failure is the direct cause, if that fails the structure has failed. The reflex of adding more concrete does not always help. A hard, vertical structure is basically a concentrator for both currents and wave energy. So you need a huge scour protection or else the wall will only work very temporally. And a narrow structure is more susceptible to piping (where water finds a path under the structure and then erodes that away). This is of course also a soil failure, but unless you are building a boat you have to interface with the soil somewhere. And that is usually where your structure will fail...
As far as their customers take them :)
- sent from my iPhone which was delivered to me via fossil fuels
But so long as it is profitable combined with globalized game theory of resources, this will continue far longer than seems rational.
https://www.scientificamerican.com/article/thawing-permafros...
>To safeguard the pipeline from possible collapse, the pipeline operator, Alyeska Pipeline Service Company, was granted permission earlier this year by the natural resources department to construct the passive cooling system to arrest the thaw of permafrost that is essential to locking the supports in the ground and keeping the slope from slumping or sliding. Alyeska is installing approximately 100 free-standing thermosyphons 40 to 60 feet into the ground. Construction is expected to take 120 days and will also include a three-foot layer of insulating wood chips atop the permafrost.
To put it more simply in the words of Henry Ford, you can buy a car in "any color the customer wants, as long as its black." You don't get choice in the market place.
I Feel like viewing them as rats without agency is extremely cynical, but also self contradictory. If we are all rats then let's act like rats and simply act on our most base desire. If you think people should try to do anything otherwise, then you admit that they have agency.
The market doesn't force you to buy a black Ford any more than it forces you to buy an F-350 with a lift kit and update the engine to roll coal. People choose to buy a car because it offers convenience, prestige, and they think it'll be better than not buying a car
(At the risk of overselling a point-and-click game, I'll literally buy it for you if you're on the fence about it. I thought it was that good).
Countries who don’t rely on methane gas (there’s no need to call it natural gas) have substantially lower co2 emissions.
So yes methane gas is a big driver of climate change.
Countries who use coal have even more emissions. 20% of US power generation comes from coal even now. More natural gas now, displacing coal, means less total emissions, even ignoring the particulate and mercury pollution from coal. So right now, natural gas reduces CO2 emissions!
https://en.wikipedia.org/wiki/Gulf_Intracoastal_Waterway_Wes...
With the current political climate in Europe, there seems to also be a general view among current climate activists that the US should export more LNG as gas consumption in EU rises.
It's quoting experts instead of describing what studies that have been done.
The older I get the more I realize the rich and powerful running the worlds corporations are probably significantly dumber than the average person.
Louisiana is, frankly, a shitshow when it comes to making smart long-term decisions. Corruption is rampant and businesses generally have politicians in their pockets. Those businesses are able to effectively offload their externalities, so they are incentivized to destroy the environment while reaping the short-term profits.
If you want any prediction as to how things will go in Louisiana, the easy answer is "poorly" and you'll be right most of the time. It's honestly hard to expect better from a place whose largest city's motto is "Let the good times roll". The local culture is just deeply broken.
At the same time, I'm really disappointed that this article almost completely glossed over one of the major challenges facing Louisiana that has absolutely nothing to do with climate change. The only tangential mention is:
> Last November, Louisiana broke ground on a $2.3 billion project to shunt some of the muddy flows of Mississippi under and past Ironton into degraded wetlands to the west. The project is being financed largely with settlement money from the 2010 Deepwater Horizon oil disaster, and aims to halt losses of wetlands by mimicking the Mississippi River’s historic path.
When the article notes:
> Since 1932, the state has lost more than 1,900 square miles of land, an area equal to the state of Delaware
It implies that the loss was primarily climate change, but that's not true at all.
Most of this loss was driven by the way the Army Corps of Engineers has managed the Mississippi River. For millions of years, the Mississippi River went through periodic oscillations. As the river dumped more and more sediment into the delta, the delta would build up until eventually it started blocking the flow. The majority of the flow would then shift to the Atchafalaya river. That river would empty into the Gulf and its delta would build up sediment. Eventually, it would reach a level where the Mississippi was again the easiest route to the Gulf and flow would change again. That periodic meandering route to the Gulf is what created the entire southern half of Louisiana and is why it is such astonishingly fertile land (well, not so much "land" now).
But for the past hundred years, the Army Corps of Engineers has been instructed to build floodwalls along the Mississippi to avoid floods in the midwest. Those floodwalls increase the overall flow rate so that by the time the river reaches southern Louisiana, it's moving too fast to deposit sediment in the delta like it used to and instead it gets washed farther out into the Gulf.
At the same time, the Corps has been responsible for keeping most of the water flowing into the Gulf going through the Mississippi side instead of the Atchafalaya so that the Port of New Orleans doesn't get hurt economically. That also means that the river isn't allowed to meander and build up sediment across the southern edge of the state.
If you think of Louisiana as a boot, this is why the "toe" (where the Mississippi dumps into the Gulf) is getting longer while the instep (the middle of the state where the Atchafalaya) is disappearing.
All of this was true and has been happening for decades before any significant climate change occurred. It's still 100% human-caused, and known, and preventable. But it's not from carbon in the atmosphere and sea level rise, though those are now exacerbating it.
If you want to learn more about engineering the Mississippi and Atchafalaya Rivers, read John McPhee's Atchfalaya, written almost 40 years ago: https://www.newyorker.com/magazine/1987/02/23/atchafalaya
If you want to learn more about Louisiana's paradoxical culture around the environment, read Arlie Russell Hochschild's "Strangers in Their Own Land".
The article and my comment are about southern Louisiana as a whole (aside from me mentioning "laissez les bons temps rouler").
* Name-your-price expenses for drilling costs
* Superfund-cleanup-excise-tax exemptions for crude extracted from certain kinds of fields
* A tax rate of 21% thanks to the Tax Cuts and Jobs Act (it was 35%)
* Explicit subsidies
* Underpricing the environmental, health, and economic damage/expenses/losses caused by fossil fuel burning (versus renewable energy)
* Near-freezing of sales taxes on fossil fuels, resulting in them falling dramatically when adjusted for inflation despite growing evidence of how widespread their harm is, and obvious growing costs from their continued use
In 2021, the federal government gave the coal industry alone half a billion dollars in "R&D" funding.
Meanwhile there's a myth that we need all this for "energy independence." We've gone well beyond "energy independence" to "fourth largest exporter of oil" and "#1 in oil extraction in the world." We extract twice as much oil as the Saudis.
One of the reasons "green" tech was so expensive for so long: the massive handouts being given to the fossil fuel industry. The next time you're filling up your gas tank and grumbling about high gas prices, think about how they receive at least twenty billion dollars a year from the feds - not counting state and local stuff.
Only in the last 2-3 years has funding for renewable energy technology started to approach that being given the (heavily established, dominating) fossil fuel industry.
What's wild is that despite those huge handouts for fossil fuel industries, solar and wind dropped below fossil fuel costs (per GWhr) well before the funding increase, and have continued to drop.
Don't even get me started on the handouts the nuclear (fission) industry gets, including free training for thousands of nuclear plant techs thanks to the navy...while the cost of nuclear power has only gone up despite being only a decade or two shy of a century worth of development.
>* Explicit subsidies
>In 2021, the federal government gave the coal industry alone half a billion dollars in "R&D" funding.
source?
>* Near-freezing of sales taxes on fossil fuels, resulting in them falling dramatically when adjusted for inflation despite growing evidence of how widespread their harm is, and obvious growing costs from their continued use
Given that there's no sales taxes at the federal level, and there's an excise tax specifically for fuels, it's a bit baffling to say that's "favorable tax regulations". It might not be indexed to inflation, but it's still less favorable tax treatment than for most other goods.
That's... the standard corporate tax rate? It really undercuts your argument when you're outraged over them not being treated specially.