How Soon Will the Seas Rise?(quantamagazine.org)
quantamagazine.org
How Soon Will the Seas Rise?
https://www.quantamagazine.org/how-soon-will-the-seas-rise-20251020/
74 comments
TIL that Earth crust is pushed down by glaciers, and that when glaciers subsides, the crust swells up a bit over years from the missing weight, pushing away water, slush and sliding glacier even faster.
Hard to fathom how "fluid" our ball of magma really is.
Hard to fathom how "fluid" our ball of magma really is.
Interesting notion, I'd never come across that before. I've seen many demos of what the Earth could look like with all the ice melted but I'm not sure any of them took what you're describing into account.
Posted 12 days ago under "Swiss Glaciers have shrunk..." and more previous to that: https://news.ycombinator.com/item?id=45503882
" The mass of ice on the earth's poles has also led to the shape of the planet via tectonics over thousands of millennia. As that mass melts and redistributes from a solid to a liquid spreading around the globe our spheroid will begin to rebound. We have sensors everywhere, even in space, so the resulting effects will not be a surprise to some when the 'mass'ive shift begins. As those tectonic events increase in frequency so too will volcanic activity so I ask if anyone else has been checking on such data? "
" The mass of ice on the earth's poles has also led to the shape of the planet via tectonics over thousands of millennia. As that mass melts and redistributes from a solid to a liquid spreading around the globe our spheroid will begin to rebound. We have sensors everywhere, even in space, so the resulting effects will not be a surprise to some when the 'mass'ive shift begins. As those tectonic events increase in frequency so too will volcanic activity so I ask if anyone else has been checking on such data? "
I think this can be summarized as “nobody knows but it might be very bad.” Mathematical models containing large uncertainties aren’t a crystal ball. They will likely be revised again.
You shouldn’t dismiss disaster scenarios since preparation for tail risks is important. But maybe don’t focus on them exclusively, either? It’s possible to keep multiple scenarios in mind, rather than focusing on one exclusively.
In California, there are wildfires, earthquakes, droughts, and (in some places) flooding to worry about, and this partly plays out via scarce and expensive property insurance.
You shouldn’t dismiss disaster scenarios since preparation for tail risks is important. But maybe don’t focus on them exclusively, either? It’s possible to keep multiple scenarios in mind, rather than focusing on one exclusively.
In California, there are wildfires, earthquakes, droughts, and (in some places) flooding to worry about, and this partly plays out via scarce and expensive property insurance.
Linking my comment from (checks notes) 9 years ago on this.
https://news.ycombinator.com/item?id=12781933
To extend the though there, the main question is not if, not when, but how long it will take. Do you bet on 90 years, 90 months, 90 days, 90 hours? Even if the change happens over 90 months (about 7 years) is that enough time to rebuild major shipping ports, forget resettling a substantial portion of the human population.
To extend the though there, the main question is not if, not when, but how long it will take. Do you bet on 90 years, 90 months, 90 days, 90 hours? Even if the change happens over 90 months (about 7 years) is that enough time to rebuild major shipping ports, forget resettling a substantial portion of the human population.
> The model suggested that ice from Antarctica alone — before any additions from Greenland, mountain glaciers or thermal expansion — could raise the seas by more than a meter by 2100.
> In a 2021 update that incorporated additional factors into the simulations, DeConto and colleagues revised that estimate sharply downward, projecting less than 40 centimeters of sea-level rise by the century’s end under high-emission scenarios.
In essence, they have no idea.
> In a 2021 update that incorporated additional factors into the simulations, DeConto and colleagues revised that estimate sharply downward, projecting less than 40 centimeters of sea-level rise by the century’s end under high-emission scenarios.
In essence, they have no idea.
I'd think that "between 0.5 and 1 meters" is an idea. Like, we aren't worried about sea level dropping, and we aren't worried about +10m by 2100. This is still useful info, even if there's some uncertainty remaining.
I like how you changed "less than .4 meters" into "between .5 and 1"
That was some smooth propagandizing you just did, I wonder if anybody else noticed. Between less than .4 (0) and 1 (1) is a much bigger window than the one you invented wholesale in your reply.
I think the grandparent might be right, and your willingness to bend the statistics when they are literally on the same page as your comment, along with others like you doing the same thing for decades, is the reason your side is losing and continues to lose the public's trust.
If the problem is really so obvious and so serious you should not feel it necessary to exaggerate. So quit it.
That was some smooth propagandizing you just did, I wonder if anybody else noticed. Between less than .4 (0) and 1 (1) is a much bigger window than the one you invented wholesale in your reply.
I think the grandparent might be right, and your willingness to bend the statistics when they are literally on the same page as your comment, along with others like you doing the same thing for decades, is the reason your side is losing and continues to lose the public's trust.
If the problem is really so obvious and so serious you should not feel it necessary to exaggerate. So quit it.
They're citing another section of the article rather than the cherry picked quotes they were responding to.
Yep, as someone else said, I'm quoting a different part of the article.
Though: from experience in science, when someone says "less than 0.4" in this kind of context, you can expect they mean ">= 0.3". And if you want to be careful and rigorous about it, you can check the 2021 Nature research article being cited here, and verify this. This article puts the contribution of Antarctica to SLR by 2100 between [0.3, 1] under that emissions scenario.
Which, again, is not "we have no idea". We're not seriously concerned about Antarctica picking up a significant amount of ice mass, nor are we seriously concerned about 10+m of SLR by 2100. Both of these would be significant if they were actual possibilities, so: when you say "we have no idea", you are not fairly representing the actual uncertainty that we have. We have some idea, just not as much as we'd like.
....as a side note, the jump from "hey, this guy isn't quoting the same thing as me" to "wow he's trying to propagandize us" is not a healthy jump.
Assuming that someone's arguing in bad faith, rather than, say, quoting a different part of the article, is probably a key piece in the vaguely anti-science mindset that you have. It's gonna color every article you read, every discussion you have, and lead you to incorrect conclusions time and again. But I don't expect this argument to have any traction, either: the emotional responses that feed into villainization tend to be pretty deeply-wired and resistant to logic.
Though: from experience in science, when someone says "less than 0.4" in this kind of context, you can expect they mean ">= 0.3". And if you want to be careful and rigorous about it, you can check the 2021 Nature research article being cited here, and verify this. This article puts the contribution of Antarctica to SLR by 2100 between [0.3, 1] under that emissions scenario.
Which, again, is not "we have no idea". We're not seriously concerned about Antarctica picking up a significant amount of ice mass, nor are we seriously concerned about 10+m of SLR by 2100. Both of these would be significant if they were actual possibilities, so: when you say "we have no idea", you are not fairly representing the actual uncertainty that we have. We have some idea, just not as much as we'd like.
....as a side note, the jump from "hey, this guy isn't quoting the same thing as me" to "wow he's trying to propagandize us" is not a healthy jump.
Assuming that someone's arguing in bad faith, rather than, say, quoting a different part of the article, is probably a key piece in the vaguely anti-science mindset that you have. It's gonna color every article you read, every discussion you have, and lead you to incorrect conclusions time and again. But I don't expect this argument to have any traction, either: the emotional responses that feed into villainization tend to be pretty deeply-wired and resistant to logic.
But they know that it is coming and we need to plan for it. 40 centimeters is still half a meter. If you filled my office with half a meter of water it would be between my butt and my ankle where I'm sitting. There are a lot of berms that couldn't withstand king tides 40 centimeters higher, especially with storm swell factored in. A lot of seaside infrastructure where I live needs to be relocated even with a lower estimate.
Obviously you get downvoted for this here, but you are absolutely correct.
Climate science is one of the most speculative fields of science, which for political reasons is rarely admitted towards the general public. The climate in 100 years is incredibly uncertain.
The general story of rising sea levels due to increased temperatures due to increased carbon in the atmosphere is of course very plausible. But it is just one of large number of effects at play and one of many ways the climate is changing. (Which isn't to say that the sum of these effects can not have server negative consequences)
Science communication around climate change has always been built around the obvious falsehood that climate models make good predictions, especially when it comes to long term trends. Instead of honestly communicating the actual state of science, which is that while specific predictions are hard, negative consequences of human intervention in the earths atmosphere likely will have sever negative consequences if they aren't mitigated, science communication has focused in on stories about "in X years Y will happen". When Y inevitably did not happen that was (and it is hard to blame people for this) taken es evidence that no negative consequences can be expected.
Edit: It is pretty surprising how anti science the crowd here is. These are just basic truths about he state of the science. Accurate climate models do not exist, if you disagree I suppose you should read a bit into the literature.
Climate science is one of the most speculative fields of science, which for political reasons is rarely admitted towards the general public. The climate in 100 years is incredibly uncertain.
The general story of rising sea levels due to increased temperatures due to increased carbon in the atmosphere is of course very plausible. But it is just one of large number of effects at play and one of many ways the climate is changing. (Which isn't to say that the sum of these effects can not have server negative consequences)
Science communication around climate change has always been built around the obvious falsehood that climate models make good predictions, especially when it comes to long term trends. Instead of honestly communicating the actual state of science, which is that while specific predictions are hard, negative consequences of human intervention in the earths atmosphere likely will have sever negative consequences if they aren't mitigated, science communication has focused in on stories about "in X years Y will happen". When Y inevitably did not happen that was (and it is hard to blame people for this) taken es evidence that no negative consequences can be expected.
Edit: It is pretty surprising how anti science the crowd here is. These are just basic truths about he state of the science. Accurate climate models do not exist, if you disagree I suppose you should read a bit into the literature.
This is completely wrong and I'm frankly not sure how you came to this conclusion from the parent comment's data.
The uncertainty is "we do not know whether the amount of sea level rise due to human GHG emissions will be closer to 40cm, or closer to 100cm 75 years from now".
Science communication regarding this has generally always expressed uncertainty. Right wing entertainment masquerading as news frequently portrays it otherwise, but that's easy to do when unencumbered by a connection to reality.
Don't confuse what is most profitable to say, with what is most correct to say.
The uncertainty is "we do not know whether the amount of sea level rise due to human GHG emissions will be closer to 40cm, or closer to 100cm 75 years from now".
Science communication regarding this has generally always expressed uncertainty. Right wing entertainment masquerading as news frequently portrays it otherwise, but that's easy to do when unencumbered by a connection to reality.
Don't confuse what is most profitable to say, with what is most correct to say.
The models are always wrong. It's virtually impossible to model something with an impossible amount of unknown inputs. Even accurately measuring the Earth over time is a joke. Unfortunately the models are presented in pop science and mainstream culture as accurate or something that we should use to create public policy.
> It's virtually impossible to model something with an impossible amount of unknown inputs.
Nah. We have a pretty good idea of what the main unknowns in climate are, and they have an associated uncertainty range. Yes, it's a lot of work to model such systems with a useful level of accuracy, but "a lot of work" is very far from "virtually impossible". ?
If the climate was that unpredictable, then the Earth would be uninhabitable.
(FWIW, I do computational modeling for work - not in climate, though - and you would not believe how much misinformation there is about modeling from conservatives)
Nah. We have a pretty good idea of what the main unknowns in climate are, and they have an associated uncertainty range. Yes, it's a lot of work to model such systems with a useful level of accuracy, but "a lot of work" is very far from "virtually impossible". ?
If the climate was that unpredictable, then the Earth would be uninhabitable.
(FWIW, I do computational modeling for work - not in climate, though - and you would not believe how much misinformation there is about modeling from conservatives)
dboreham(1)
rising sea level, is only one symptom of whats happening.
https://climatecosmos.com/climate-news/why-the-tropics-could...
it seems there will be big problems in the 50-75 year span.
https://climatecosmos.com/climate-news/why-the-tropics-could...
it seems there will be big problems in the 50-75 year span.
I’m gonna guess that sea level rise will end up being one of the lesser problems introduced by climate change
I'm not so sure, ground water will turn salty and make large swaths of land unlivable and river mouths will change stream upwards so all dike infrastructure as it is now will be unusable.
This is already happening along the internal Eastern Shore exposed to the Chesapeake Bay in Maryland were I live and it is documented in recent publications by those accredited in such topics. The low lying wet forests that have lived just above the salt line are now all dying from the rising salt water intrusion. I have one of those low lying forests right behind my property and in the last 10 years I have witnessed all the trees within this area die. As an avid walker of these shores near daily in the last 15 years I have also witnessed unprecedented erosion of the shoreline of at least two vertical feet thus extending the beaches however these are not those types of beaches.
As a collector of things lost in time, such as Native American artifacts of which I have found thousands immediately around me in the last 15 years, I can say that erosion does have its benefits. Just as we are now reading from those exploring glaciers finding previous human tools and more. The word "benefit" here is clearly subjective.
As a collector of things lost in time, such as Native American artifacts of which I have found thousands immediately around me in the last 15 years, I can say that erosion does have its benefits. Just as we are now reading from those exploring glaciers finding previous human tools and more. The word "benefit" here is clearly subjective.
A very large fraction of humanity lives in zones that will end up being flooded, this is already happening in some parts of the world.
For instance, Vanatu:
https://climateknowledgeportal.worldbank.org/sites/default/f...
There is nuisance flooding, which is definitely up already in many parts of the world, and then there is the kind of flooding that essentially makes it impossible to live in certain places. My own country (NL) has been working since a bad flood in 1953 to raise the various flood protection systems to account for rarer events and the mechanisms put in place have already been triggered several times. Right now they're working on raising the whole protection level another meter (three feet), and if necessary they'll do more than that but there are some complicating factors. At some point the rivers won't empty any more and you end up with either reverse flow or internal flooding simply because that river water has nowhere to go to.
For instance, Vanatu:
https://climateknowledgeportal.worldbank.org/sites/default/f...
There is nuisance flooding, which is definitely up already in many parts of the world, and then there is the kind of flooding that essentially makes it impossible to live in certain places. My own country (NL) has been working since a bad flood in 1953 to raise the various flood protection systems to account for rarer events and the mechanisms put in place have already been triggered several times. Right now they're working on raising the whole protection level another meter (three feet), and if necessary they'll do more than that but there are some complicating factors. At some point the rivers won't empty any more and you end up with either reverse flow or internal flooding simply because that river water has nowhere to go to.
Do you know the populations of the world that will be displaces, and the amount of real esate that will be affected by this?
Sea rise is not just about flooding, but it affects sewers and infrastructure well before affecting properties.
Sea rise is not just about flooding, but it affects sewers and infrastructure well before affecting properties.
You need to have extreme weather into account. Global sea rise is a slow process, it won't happen overnight, and even with an accelerated, but not catastrophic, melting of some of the fragile glaciers in Antarctica it will take years.
Extreme weather, in the other hand can affect big areas for extended amount of time, right now. In 2022 a third of Pakistan ended flooded, in 2024 there were big floods in parts of Europe and South America. Droughts, extended forest fires, tornadoes and similar has been changing in area patterns and strength in the last years. And things may get extremer in the coming years
Extreme weather, in the other hand can affect big areas for extended amount of time, right now. In 2022 a third of Pakistan ended flooded, in 2024 there were big floods in parts of Europe and South America. Droughts, extended forest fires, tornadoes and similar has been changing in area patterns and strength in the last years. And things may get extremer in the coming years
Something like 2 billion people rely on glacier melt for their fresh water supply and these supplies will end abruptly before catastrophic sea level rise.
It will be a big one for people living near the coast. Basically all port infrastructure will need to be moved. Of course there a things like extreme heat waves, cold snaps, lack of rain or floods that will make a lot of land unlivable too. Lack of food will be another thing. But land being under water is not a lesser thing at all, as it makes the land unavailable.
As long as you don't live on an island or have coastal property...
I think the point was more that even if you're on a coast a lot of other problems are more likely to impact you first: higher energy and more frequent hurricanes, insurance, costs, etc.
It's not as a-vs-b as this. Rising sea levels will increase the damage of those more frequent hurricanes long before one's house falls into the sea. And that increases insurance costs, and so on. The whole thing is a single system with a giant feedback loop.
It could be an a vs b thing if a effectively finishes the conversation before b gets going.
A lot of areas won’t make sense to insure due to storm risk well before they’re at risk from literal sea level risk.
A lot of areas won’t make sense to insure due to storm risk well before they’re at risk from literal sea level risk.
I suspect most islanders and coastal property dwellers will be wrecked by volatile weather first
There's a sweet spot where i will eventually have coastal property.
Temporarily...
Or say, a country bordering Bangladesh. Sea rise of 1 meter would inundate 10% of Bangladesh, a country of 170M in 150,000 sq miles. I suspect a refugee crisis in Bangladesh would end in genocide…
nerviosly coughs in Dutch
I wonder if the dutch have a plan to evacuate the whole country in say, a year time, in case walling the seas no longer feasible?
Not in an emergency scenario but more like "it doesn't make sense to stay here anymore".
Not in an emergency scenario but more like "it doesn't make sense to stay here anymore".
Why would it no longer be feasible?
I mean, I can tell you why. It's not feasible if it costs too much. If it makes sense (i.e. the land is worth X and cost of a wall is some fraction of X that people can afford) people will do it.
I mean, I can tell you why. It's not feasible if it costs too much. If it makes sense (i.e. the land is worth X and cost of a wall is some fraction of X that people can afford) people will do it.
okokwhatever(1)
phendrenad2(1)
bilsbie(3)
"Depending on future emissions, the IPCC now projects an average sea-level rise of half a meter to 1 meter by 2100"
Someday they will realize that we are still in an ice age.
We've been in an ice age for millions of years (standard definition of an ice age: there is persistent ice sheets at the poles; on Greenland and Antarctica).
Within ice ages, there are glacials and interglacials. Glacial periods are what normal people think of when they say "ice age"; like when the ice sheets covered Canada and extended down to Chicago/NYC areas.
Without manmade climate change, we'd be slowly sliding back to another glacial period. So in that sense, the warming is welcome, but we're overdoing it and shooting too hard in the opposite direction.
Within ice ages, there are glacials and interglacials. Glacial periods are what normal people think of when they say "ice age"; like when the ice sheets covered Canada and extended down to Chicago/NYC areas.
Without manmade climate change, we'd be slowly sliding back to another glacial period. So in that sense, the warming is welcome, but we're overdoing it and shooting too hard in the opposite direction.
Not how soon will the seas rise, but in which direction are they trending? The world is not static - it's dynamic, always changing. Long before human civilization, the environment was getting warmer, then cooler, then warmer, etc.
Instead of freaking out about it, work to understand how we as a civilization can make it through the changes. Attempting to hold the environment stable is like plugging dikes with your finger.
Instead of freaking out about it, work to understand how we as a civilization can make it through the changes. Attempting to hold the environment stable is like plugging dikes with your finger.
Humans are causing a change to the environment drastically faster than any normal ebb and flow. In the same way that you can get from 0-60 either by pushing on the gas pedal, or being hit by a train, rates of change matter a lot.
I don’t think anyone here is advocating for freaking out about it, and I do not see any suggestion we should that you’re replying to.
Also, it’s pretty clear from the IPCC report that holding the environment stable isn’t an option. At this point about 0.5m minimum sea level rise this century is probably locked in. However a 1m rise might not be.
So yes, the issue is that either way policy planning needs to be considered in the long term.
Also, it’s pretty clear from the IPCC report that holding the environment stable isn’t an option. At this point about 0.5m minimum sea level rise this century is probably locked in. However a 1m rise might not be.
So yes, the issue is that either way policy planning needs to be considered in the long term.
A great example of just how extreme things can get was the last major climate change event ~10,000-20,000 years ago (which will likely be minuscule in comparison to what we're going through now in the geological sense once this plays out).
The Channeled Scablands of Eastern Washington[0] have a very distinctive geology. For many years it was believed that these features were carved out slowly over hundreds of thousands of years. It turns out they we created in hours, around 15,000 years ago (humans were already living in WA at that time). They were created by the Missoula floods. There used to be a glacial lake over what is now Missoula Montana which would have current day Missoula under 1,000 feet of water. The glacial damns holding back this lake started to break down resulting in frequent floods the scale of which it's hard to fathom. The peak flow is estimated to have been 6.5 cubic miles per hour (for context, the peak flow observed over Horseshoe falls was 0.0055 cubic miles per hour, the Amazon river flows at an average of 0.18 cubic miles per hour)
Imagine driving East on 1-90 from Seattle towards Spokane, then as you get through the Cascades you suddenly see a 200 foot wall of water racing towards you across the horizon.
That event was in the past and it still took us a long time to piece together what actually happened. As we head into states of climate never witnessed by humans, it's genuinely hard to predict what might happen other than "this probably won't be good". Humans have made a lot of progress in the last 10,000 years, but it's no coincidence that the last 10,000 years have been some of the most stable in the Earth's climate history.
0. https://en.wikipedia.org/wiki/Channeled_Scablands