How Climate Resilient Are the Largest Cities? | Hacker News Reader

How Climate Resilient Are the Largest Cities?

alphageo.ai

50 pointsasib68 comments

There's a very cool project wrapping up here in Zurich where they built a relief tunnel from the sihl river underground downhill to lake Zurich to handle 500-years floods.

One weekend they let people walk the length of the tunnel from the river to the lake. It was a pretty steep slope and about 3/4 down the walls of the tunnel changed from smooth to rough. They had calculated how fast the water would be moving when it hits the rough part and then how much that would slow it down.

Then at the bottom instead of emptying directly into the lake it comes flying out of the tunnel and smashes into a giant cement wall then flows under a roadway into the lake.

Cost was $200 million. A 500-year flood would flood downtown Zurich.

https://www.zh.ch/de/planen-bauen/wasserbau/wasserbauprojekt...

That IS very cool. I can’t help but appreciate the insight and forethought that goes into the decision to construct such massive waterworks projects.

The cross-border system fed from the Elan Valley in the UK is like this, Wales is famously very rainy due to its hills and the Victorians exploited this by damming the Elan Valley and gravity-feeding the water from the Cambrian Mountains all the way to Birmingham which was a rapidly growing industrial centre. There's no pumps, it was all calculated to drop 170 feet over 73 miles!

It's a really stunning place to visit as well, mid Wales in general is so pretty and the dams themselves are ornamented in a way nobody would bother with today. Of course the Victorians got away with things that would be unthinkable now, when Liverpool did the same approach of flooding Welsh valleys to water English cities in the mid 20th century it was very controversial because the scheme flooded a majority Welsh-speaking village and the language was in a fairly steep decline then; nowadays there's a lot more protections for Welsh.

our facility builds features to only 25 year floods, and that appears to be typical in the US.

Nice to see at least one country that has a government that thinks ahead and is proactive. Here our local government is busy issuing building permits for inundation zones (seriously!) because the land is cheap to build on for some reason and if they're packed full of apartments they can collect a ton of property taxes from them.

São Paulo is in the "green" but they were supposedly around two weeks from running out of water for municipal distribution in 2014/2015. A city of that size without water would not do well.

https://en.wikipedia.org/wiki/2014%E2%80%932017_Brazilian_dr...

https://www.smartcitiesdive.com/ex/sustainablecitiescollecti...

EDIT: added timeframe

There is plenty of water around São Paulo, the problem is the infrastructure to use it.

How is Miami not near the bottom of the list? Every time there is a moderate rainfall, streets flood like crazy. Plus we are in hurricane alley, and some models project that most of the Florida peninsula will be under water in 50-100 years.

This is not true.

Even in the most cataclysmic scenarios, scientists project Sea level to rise 2m by 2100, and most of Florida is above that level.

https://climate.mit.edu/ask-mit/what-are-best-and-worst-case...

As a researcher in this general area I would not say 2m by 2100 is a consensus view of the worst case scenario see [1].

Here is a useful scenario for understanding what different SLR scenarios mean for the states [2]

[1] https://www.ipcc.ch/srocc/chapter/chapter-4-sea-level-rise-a...

[2] https://coast.noaa.gov/slr/

("most of the Florida peninsula will be under water in 50-100 years" is certainly not true, however, Miami would be in a very difficult spot at 2m SLR)

Your link implies less than 2m, strengthening my point?

I said 'even in the most cataclysmic scenarios'

Yes, I was agreeing with you. I apologize for being unclear.

The problem with South Florida isn't that the sea level will rise enough to directly flood everything with seawater but rather with drainage of rainwater. There is already only a small gradient for rainwater to drain off into the ocean. If the ocean level rises even a little then drainage slows and flooding increases. The whole region sits on a karst substrate so dikes aren't effective; they'll need active pumping.

Ok, well 'most of the Florida Peninsula' is significantly above 2m elevation.

Yes, what's your point? That doesn't refute the prediction that even a slight sea level rise will cause more frequent flooding in South Florida due to slower drainage of rainwater.

My point is I was replying to a comment that said most of Florida will be underwater in 2100, which is not true, as I said.

What is your point?

My point is that while most of Florida won't be constantly underwater in 2100, significant parts of it will be underwater more often than they are now unless there are major, expensive upgrades to flood control infrastructure. While the original claim might have been overstated there are likely serious problems coming that will hit Florida harder than most other states.

Most Americans are unaware of both how many people live outside of the United States and how bad things can get there.

I had asked a question "how is Miami not on the list at all" and then realized that the table is actually an image not a table so I couldn't search it.

It's on the list. #34 out of 72, middle of the pack. Within the U.S. Chicago, NYC, Philadelphia, LA, and DC are above it. Houston, Dallas, San Antonio, and Phoenix are below it. They seem to weight heat-stress pretty highly in their rankings, hence why all the TX/AZ cities are at the bottom and are joined by South and Southeast Asia.

The list is a little weird in that I can't find any population-based reason why Miami would even be on it: it's almost the top-10 U.S. cities by population, but missing San Diego or any SF/BayArea city, while Miami & DC are #41 and #22 respectively. If you go by metro area it explains why Miami & DC are there and why Dallas & Fort Worth are condensed, but not why Atlanta is missing and San Antonio is included.

My guess is that Miami and Washington are there for essentially rhetorical reasons. Miami is often talked about as a city that's vulnerable to climate change, and Washington is the capital.

miamia was likely already a swamp; nature already said: "guys, water lives here"

I'ma guessing that's the reason.

For a USA county level assesment of climate risk I reccomend this site https://map.climatevulnerabilityindex.org/map/cvi_overall/us...

I like that map and it goes all the way down to the tract level of detail. I was confused about the range of risk then saw the sub-heading "Score combining environmental, social, economic, and infrastructure effects on neighborhood-level stability.". Thinking in terms of neighborhood stability make more sense when viewing the percentiles.

My neighborhood is in the 55th percentile but then right across the main street, where the houses are bigger, it drops to 25th percentile. Both neighborhoods seems pretty stable but I guess when the chips are down crime is going to increase faster in a poorer neighborhood.

There is no legend which is frankly surprising and disappointing

Hmmm... I see a legend

It doesn't seem to account for earthquakes, which is appropriate, since it's a climate vulnerability index. But definitely something one would take into account when deciding where to settle.

Chicago resident here.

Not disputing the methodology, but our state is the nation's leader in tornadoes (by more than a factor of 2) due to Niña/Niño this year, and Chicago spent a few days this summer with the world's worst air quality due to Canadian wildfire smoke.

Obviously, "resilient" ⍯ "unaffected".

Not the leader yet and not anywhere close to "factor of 2" also the effects of el nino this year haven't even started really. It's more of a winter weather phenomenon.

Current tornado count for Illinois: 210 ( as of 8/29 ) Current record holder is Texas: 244 in 2015

However, Texas is big i don't have the math handy but I bet Illinois is well ahead in terms of tornados/square mile. ..maybe that's where your "factor of 2" comes from? Or maybe people affected since most Tornados in Texas don't affect much except maybe fences and powerlines.

I don’t have stats to speak to the validity of their claims, but I think that we parsed their comment in different ways:

- number of “tornadoes due to Niña/Niño“ (my reading)

- “number of tornadoes” (total for the year), with Niña/Niño being why it’s that way (sounds like your reading, since those numbers are the overall)

I have a hard time believing this site also. When I looked at their methodology at how this list was created, it said "Please fill out our Methodology Request Form, and a member of our team will get back to you, typically within one business day.". As far am I am concerned, I can safely ignore this site.

https://docs.alphageo.ai/climate-resilience-suite/climate-ri...

This is far outside of my wheelhouse, but I have some serious questions about the methodology here.

I dug into what they call a "resiliency checklist", which is what looks to be a set of questions that have qualitative answers which are subjective at best. This information looks like it is fed into the CRRI, the data set that substantiates the city-wide scores used to power this report.

I am very skeptical that these 2 things happened:

  - They captured a representative set of key assets that go into making a "city"
  - The answers they received are calibrated or are meaningful enough to make these large conclusions

Many cities are heat sinks and make the problem worse locally due to lack of tree cover and an overabundance of concreta and tar.

Cities being resilient is one thing. It won't contribute to make agriculture resilient.

Really smart point.

The problem is not that we couldn't improve cities to sustain -30 Celsius winters. This is doable. The problem is that places suitable for agriculture would vanish in the upper half of the continent. Canadians need to import many of their food and they are like 40 million people, Europe would need to find a way to feed 500 million people.

Cities resilience to war will be a concern much before climate resilience.

Good thing we've been working on beating photosynthesis efficiency of turning sunlight into carbohydrates (e.g., sugar) by using special electrolysis cells to synthesize plant-accessible carbon-nutrients (one kinda-successful (in beating natural leaves with PV based sunlight electricity and their electrochemistry)) attempt focused on generating a nutrient solution rich in acetate from CO2 feed (and electricity); that's one of the energy carrier molecules that existing plant biology can efficiently utilize.

https://doi.org/10.1016/j.joule.2024.09.011

And note that by exploiting winter time solar yield and the grow houses with such technology not using sunlight directly and thus allowing easy and efficient thermal insulation, production could run year-round just with the amount of grow houses "online" varying with the average solar yield. Also gives convenient off-times (if they rotate which building runs through the winter) for maintenance.

And eating less meat or at least feeding the meat animals efficiently produced (but not as "tasty/varied/textured") plant/algae(/possibly-microbiological with bacteria or yeast) feed instead of things like Alfalfa that are very resource intensive to farm, would also help a lot with these issues.

Probably we should get back to doing grain bunkers as strategic reserves, though, lasting long enough to realize the problem, slaughter 80% of livestock, and plant low-failure-risk human suitable food crops on farmland that previously had feed crops for those no longer living 80% and land that had things like corn dedicated for ethanol that's then added to gasoline. Ideally ofc. we'd not need to cull as much life stock and could instead just slightly reduce new breeding and switch those corn fields to human food.

At -20 Celsius we will eat more meat, not less.

I'm having a headache trying to parse the first paragraph, but definitely we didn't beat the photosynthesis. Not yet.

Sorry about the writing :(

We have beaten it but only for an output that's approximately "green smoothie".

We're already better than just LED grow lights for e.g. lettuce, though, from how I recall the linked paper.

Unsure how you conclude that cold outdoors necessitate more meat though; aside from some micronutrients vegan diet works just fine so reverting back to "meat only on Sundays" 1910 style household dinner menu structures would work fine...

Most people could, for example, do with replacing the caloric intake from half the portion of any non-vegan food they consume, with potato.

If outdoor farming breaks from climate meat will get more expensive...

Vertical solar panels mounted like fence panels between fence posts high enough to not get covered by snowdrifts will produce electricity year-round; and we only need around 3x as much solar farm currently to power sealed grow "basements" than the same plant output would need if just farmed on an open field (assuming climate is matched and weather is average). The benefit of it is just that the panels can be other places (like noise barrier walls next to an urban highway) than the plants and the climate can be freely picked. Also no unlucky correlated dry spell weather events that can cut 100 million people's worth of harvest yield down to half or worse.

Grow houses won't fail collectively as much as farming weather is correlated across a region. Pretty much just need to keep measures around to prevent the plants from freezing just because the electric grid falls over for 3 days in winter.

Canada is a substantial net food exporter…

Some foods yes, there are huge fisheries, but not agriculture. (I admit that should had been more precise in my post)

After the British Columbia University web, Canada still seems to import like a 75% of the fruits and a 50% of the vegetables eaten by Canadians (excluding potatoes). Apparently, this is one of the problems with the tariffs.

Humans have been working on this for centuries and we've never harvested more food than the present moment.

https://hannahritchie.substack.com/p/food-projections-2025

2026 Summer in Europe signals something like the past centuries are not really representatives of the challenges we face to be able to sustain agriculture as we did before.

Between fruits and vegetables that literally dried up to the Sun (with a unusually hot and dry Spring season), critical drinking water availability and drying up rivers, the coming year is going to be interesting to track.

My concern with this analysis is that the headline "conclusions" depend on a proprietary composite index and assumptions. Where are the underlying data and methodologies for independent evaluation?

I was also surprised by how little attention the analysis gives to China and India. It's like measuring the smoke from a candle while standing next to two forest fires. The real-world impact is to decimate the economies of Europe while industry moves to China and India, who have no meaningful guardrails at all, making the claimed problem worse.

Mmmm what to say.. I lived in Beijing, Shenzhen and Shanghai and I would say these cities are not really resilient. Yeah no major dams or glaciers that will trigger natural disasters but every typhoon season parts of these cities are flooded. Past three years I have been knee deep in water 3x a year in Shanghai, I have never seen anything like it (coming from Europe).

Honestly this list sounds like total BS. Doesn’t Chicago have a bunch of people die every time there’s a heatwave because of lack of AC and such? How are they possibly the best prepared city on the planet for climate change? The whole methodology here seems suspect at best.

Chicago is lowest for adjusted risk because it just scores very low for physical risk on their scale. Compared to other cities the adjustment to its risk score for resilience is about typical - not great and not terrible - which suggests that yes, for what physical risks it does face (summer heat) it could probably do more to reduce those risks.

david pogue in "how to prepare for climate change" mentions chicago and the great lakes area in general as a "climate haven", so the idea is not complete bs.

> Doesn’t Chicago have a bunch of people die every time there’s a heatwave because of lack of AC and such?

There was a heatwave in the 1990s that killed thousands in Chicago. Since then, the city has done a lot to handle them. While people still die during heatwaves, not as many as would have prior to all of the planning and effort. I guess it depends on how you define “a bunch”.

The growing risk factor for Chicago is flooding and dangerous storms. So far this is causing economic damage but not really killing anyone. Who knows if that holds.

Friendly reminder that the NOAA's USHCN reference network of well sited thermometers with continuous temperature records and no urban heat island bias shows no warming trend over the past ~20 years.

https://www.ncei.noaa.gov/access/crn/

> USHCN

This was the network that had heat island issues because it was volunteer stations highly biased towards urban areas.

It was superseded by USCRN (which you linked to) in 2005. USCRN is 114 stations intentionally situated away away from development. USCRN shows MORE warming than global networks, around .3* C per decade, and it recorded 2024 as the warmest year on record.

The article you are indirectly citing (https://dailysceptic.org/2023/04/08/u-s-government-has-an-ac...) is easily disproven if you analyze the numbers: https://www.theclimatebrink.com/p/the-most-accurate-record-o...

Replying to you again because I would like to know what you think of the evidence presented above? Maybe download the data and try and run it yourself? What info do you need to see that the temperature is changing?

Pretty darn resilient considering we’ve predicted climate doom for the last 30 years and they’re still standing.

If you predict an event that is 100 years away and 30 years pass, does the event that is still 70 years into the future vanish simply because the present arrived as predicted by the forecast?

Mind you, the forecast told us that we're still fine in 2026.

I'm basically on your side here, but there were plenty of models predicting catastrophe by now.

Ah yes, I believe one of those models was called the Strawman Model, generated by Elliot F. Strawman during his tenure at MIT. He was forced into retirement due to his deep embarrassment over his model’s inaccuracies.

Anyway, Illinois is about to break the all time record for tornadoes by a single state, previously held by Texas, during the strongest El Niño ever measured. I’ll be proud tucking my kids in and telling them as long as they pray hard enough to the Gods of technological progress, we’ll be guaranteed to stumble upon a carbon sequestration technology akin to the Haber process and they won’t have to be forced into a Sophie’s choice when there’s only enough clean water for 2 of their 3 children.

Take a breath. Read what I said.

Worth noting Texas is having one of its quietest tornado years in the ~20 years of comparable data, at the same time. Which is the problem: the reliable detection era is about 30 years, and the preliminary dataset behind these headlines starts in 2004. The IPCC has low confidence in observed trends in severe convective storms for exactly this reason. And your El Niño point argues against you, since El Niño is associated with suppressed spring tornado activity in the southern Plains, which is what we're seeing in Texas.

From what I read Texas will have larger and more intense heat domes. On the plus side, this high pressure shifts tornado alley towards the east away from Texas. On minus side, Texas will be the new Arizona.

Mind sharing some? I often hear people believe climate scientists frequently overstate things, and I can’t recall seeing good examples of this.

Watch “an inconvenient truth”

Just ask ChatGPT

“What were the major predictions and timeline in the movie An Inconvenient Truth?”

He got some things wrong but was right on a lot.

I was responding to the claim that many models had predicted catastrophe. An Inconvenient Truth is a movie made by a politician. It, of course, chose to depict the more extreme ends of probabilities. And despite that, I think it stands up pretty well, all things considered.

That doesn't relieve people of the responsibility of having enough scientific literacy to understand that 30 years is only an instant on geological time scales. And the fact that we see meaningful change at all on this time scale is very concerning.

> And the fact that we see meaningful change at all on this time scale is very concerning.

or it's noise. I'm also on your side but be realistic.

Places that used to be 32C in summer are consistently hitting 36C+. It absolutely sucks to be outside in those temps. You are running from aircon to aircon. Doom scenarios of unbearable heat is definitely true.

Germany had two sizable heatwaves this summer, of which one was so intense that for the first time in about "ever" ACs tripled/quadrupled in price (note this includes those on online stores where the shipping times would allow for trucking them in from all across central Europe)... I'm not referring to installation labor/technicians even. But like window units and similar ones that don't rely on HVAC technicians to take out the box and turn on.

What does any of that have to do with what I said? I agree with you but I guess not with enough zeal.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201...

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