Meeting Paris Agreement ambition could save a lot of sea level rise

Latest models project a bumpy road with big risks.

Read the whole story

 

[Hookbrah]

Rindan
I loath how the climate change movement has adopted an abstinence only approach to dealing with climate change, and get angry if someone suggests expresses any other opinion than totally helpless before changing climate.

Was the last time you checked in with “the climate change movement” in the 1990s? Adaptation has been a major part of the international agenda for at least 25 years. If people get angry maybe it’s because you sound a bit too much like “meh, no big deal, we can adapt.” Which is like saying that crashing your car isn’t that big a deal because the people in front have airbags (never mind the passengers in the back).

 

[Emon]

The answer is simple. Just pump sea water from the warm coastal rim to the cold interior of Antarctica. I'd go nuclear plant for the pumps, but there is a lot of wind energy from the cold winds blowing down to lower elevation.

Now the bad news: you only need about 362 km^3 of water pumped for each mm of sea level rise.

http://www.antarcticglaciers.org/glacie ... evel-rise/

Sarcastic? Not really. Impractical, most likely. But Elon might make it work, if you tell him Bezos is ahead of him in trying it.

(Fixed link, and added gripe about cm's. Inches, feet, or proper MKS SI units please)

It may well come down to insane engineering efforts to avoid extinction.

I'm really intrigued by the idea of space based mirrors to block out sun light. They could get us an adjustment knob for the Earth's temperature. If we fuck up and cool too much, just turn them away or deorbit them. It won't solve ocean acidification or anything like that, but maybe it could be a good e brake for our massive fuckup.

The cost of chucking up that much mylar into some orbit between the Earth and sun might not be so crazy given what SpaceX is doing. Starship and Super Heavy are far from the largest they plan to ever build.

 

[numerobis]

I have a question about the flooding of the below sea level basins. How fast is the rebound in such a scenario? We are able to measure the effect of water in California in drought and non drought years. Does that help predict it? That is, how long before rebound pushes the land back up, and adds that entire volume to the whole flooding disaster as well?

Naively I expect it to be a slow process like continental drift, but faster than that because it's simple buoyancy?

It’s tens of thousands of years — there’s still rebound from the last glacial maximum going on.

The rebound should be largely neutral, probably slightly increase ocean volume. The rock is largely incompressible, so when you put a couple km of ice on land, it pushes that land down but raises nearby land (or ocean floor) that’s not glaciated. This only affects the volume of the ocean if the land that gets squished down is above sea level and the land that rises is below sea level, or vice versa. If they’re both above sea level or both below, it’s neutral.

A fun one is as you increase the depth of the ocean, it squishes the continents up, mitigating the sea level rise! At totally irrelevant amounts and speeds for human civilization of course.

 

[McTurkey]

The Antarctic and Siberian beaches are going to be f^cking beautiful.

 

[McTurkey]

The answer is simple. Just pump sea water from the warm coastal rim to the cold interior of Antarctica. I'd go nuclear plant for the pumps, but there is a lot of wind energy from the cold winds blowing down to lower elevation.

Now the bad news: you only need about 362 km^3 of water pumped for each mm of sea level rise.

http://www.antarcticglaciers.org/glacie ... evel-rise/

Sarcastic? Not really. Impractical, most likely. But Elon might make it work, if you tell him Bezos is ahead of him in trying it.

(Fixed link, and added gripe about cm's. Inches, feet, or proper MKS SI units please)

So... that's around 21 million cubic kilometers of liquid water for the entire Antarctic ice sheet, or 1000 times the entire volume of the Great Lakes. Nearly 60 meters of sea level rise would, of course, cause almost incalculably expensive and deadly levels of destruction and migration. I'm going to go ahead and posit that we won't figure out how to do the first before the second one wipes out civilization.

We're in stupidly dangerous territory here - we've basically locked in enough global temperature rise that there are only two paths: total and immediate stoppage of all human industry (lol, no), or flooring it with the hope that we figure out how to produce enough sustainable energy that we can rapidly decarbonize the atmosphere by the time the millennial generation hits retirement age.

I don't know where to start on the math, but I suspect that the energy requirements for moving that volume of water in a useful timeframe is probably going to be a significant multiple of total current global energy production. I mean, we could perhaps design nuclear weapons of sufficient power to vaporize a whole lot of water, but I don't think we need continent-sized typhoons and hurricanes swirling about. Although that is a super fascinating world to envision...

I suppose this is another reason to get serious about building a human settlement on Mars. Not just for species redundancy, but because our efforts to transform the radically different environment might just end up being the key to figuring out how to reverse some of the more severe damage we're inflicting here.

 

[Snark218]

9-12 inches in 80 years!

Wow how can we ever cope with that?

Coastal cities will still be there. Most no one will notice.

The average elevation of Florida is 72 inches. Some places are 36 inches.

Yeah, wow, how could we ever cope with that? The lower parts of Florida have vast amounts of buffer height. I mean it would take another 2 rises of 12" before those parts are permanently underwater.

Why would Florida possibly have to worry about this in the future? They are already handling it. See with your own lying eyes!

PS: the worst case is 18", so there is also the part where you did not even read the whole article.

It seems like the risks in S. Florida are going to be "hidden" by the lunar nodal cycle for the next few years.

The lunar effect is currently in a downcycle, knocking about an inch (~2.5 cm) off high-tide levels over the coming 4 years.

The next peak is 2035, I'd place a bet on people freaking out by then. If I had Florida real estate I'd consider getting the hell out of there in the mid-2020s.

"Who's gonna buy it, fucking Aquaman?!?!"

 

[Snark218]

I too want to reduce our CO2 emissions, and that certainly is the best solution, but I loath how the climate change movement has adopted an abstinence only approach to dealing with climate change, and get angry if someone suggests expresses any other opinion than totally helpless before changing climate..

I loathe dipshits like you who think they can speak to the motives and goals of the fields of global change, despite their total ignorance of same. I mean, seriously, you think we haven't been discussing adaptation and resilience for the past 30 years?

 

[Snark218]

9-12 inches in 80 years!

Wow how can we ever cope with that?

Coastal cities will still be there. Most no one will notice.

Miami is already having issues with sinking land. New Orleans is under sea level. NYC flooded with superstorm Sandy. It's only going to get worse.

Remediation is either a fading dream or an active delusion.

Mitigation is all that's left.

The nation of Netherlands would like to disagree. Remember that time they recovered nearly half of their nation from the ocean starting the 1500s?

That is my point. We can mitigate the affects; I don't think we can stop or even greatly slow the process. By all means we should try to do so; flattening THIS curve eventually is gonna have to happen. But we shouldn't count on it turning anything around. We need to spend our climate change $$$$ as much on moving people to higher ground (or walling off the low ground, but eventually the sea always wins), finding ways to desalinate farm land, better ways of managing water is just as important as nuclear, wind, tide and solar power and finding a way to cycle carbon out.

Climate mitigation is reduction of GHG emissions and drawdown of their atmospheric concentrations. Climate adaptation is figuring out how to cope with the warming we're locked into, which is what you're discussing here.

 

[graylshaped]

9-12 inches in 80 years!

Wow how can we ever cope with that?

Coastal cities will still be there. Most no one will notice.

Miami is already having issues with sinking land. New Orleans is under sea level. NYC flooded with superstorm Sandy. It's only going to get worse.

Remediation is either a fading dream or an active delusion.

Mitigation is all that's left.

The nation of Netherlands would like to disagree. Remember that time they recovered nearly half of their nation from the ocean starting the 1500s?

Let's not let gloom over global warming transform into a sense of helplessness and pretend like the only mitigation effort you can take is to stop dumping CO2 or simply die. You can in fact build sea defenses in many places, with a cities like New York being an obvious candidate for a place well worth defending from the sea rather than retreating from it.

I too want to reduce our CO2 emissions, and that certainly is the best solution, but I loath how the climate change movement has adopted an abstinence only approach to dealing with climate change, and get angry if someone suggests expresses any other opinion than totally helpless before changing climate.

Lots of places can't deal with a sea level rise and will have to evacuate before rising waters, but New York City is not one of those places, because we will defend it, as we are more than capable of doing.

I loath idiots who think engineering a band-aid is preferable to engineering prevention.

 

[Northbynorth]

Reports like this are important, since it lifts the eyesight beyond 2100.

Since 2100 was arbitrary chosen as the end point for models runs, due to limited computer resources (models in the 90s took several month to finish a run, despite low resolution), many politicians and other stakeholders seem to think that everything end in 2100.

It will take centuries before the sea level has reached an equilibrium after 2 degrees global warming.

Edit: spelling and clarification

 

[Jiveformation]

I think it's good to have a range of plausible scenarios for how much sea level increase we could expect under the most likely range of scenarios, but one scenario that I don't see highlighted often enough is basically the worst case scenario that I don't think many people are aware of. If we ignore global warming entirely and just let the temperature keep rising, what happens when ALL of the ice caps melt?

That's more or less what the RCP8.5 scenario in the article is: a worst-case scenario. It's named that because it's based on 8.5° C of warming, which is basically what we'd expect if emissions continued to rise throughout the next century with zero mitigation. As the article mentions, the uncertainty is pretty huge, but even based on that RCP8.5 scenario (bottom right graph) there's basically no chance the ice caps will melt entirely in the next century (or even the next three centuries).

That said, you're right that if all the Antarctic and glacial ice in the world did melt entirely there would be roughly 70 meters (230 feet) of sea level rise.

RCP8.5 is not "8.5" degrees warming. It's "end-of-century radiative forcing of 8.5 watts per metre squared – W/m2 – forcing increase relative to pre-industrial conditions".

 

[C64 raids Bungling Bay]

The answer is simple. Just pump sea water from the warm coastal rim to the cold interior of Antarctica. I'd go nuclear plant for the pumps, but there is a lot of wind energy from the cold winds blowing down to lower elevation.

Now the bad news: you only need about 362 km^3 of water pumped for each mm of sea level rise.

http://www.antarcticglaciers.org/glacie ... evel-rise/

Sarcastic? Not really. Impractical, most likely. But Elon might make it work, if you tell him Bezos is ahead of him in trying it.

(Fixed link, and added gripe about cm's. Inches, feet, or proper MKS SI units please)

It may well come down to insane engineering efforts to avoid extinction.

I'm really intrigued by the idea of space based mirrors to block out sun light. They could get us an adjustment knob for the Earth's temperature. If we fuck up and cool too much, just turn them away or deorbit them. It won't solve ocean acidification or anything like that, but maybe it could be a good e brake for our massive fuckup.

The cost of chucking up that much mylar into some orbit between the Earth and sun might not be so crazy given what SpaceX is doing. Starship and Super Heavy are far from the largest they plan to ever build.

Space based mirrors are also de facto solar sails. May need to orbit around the earth, because you probably can't just have them orbiting the sun inside the earth's orbit. You might want to aim the reflected energy somewhere useful too, we're going to need power in space, and nukes won't do it all.

BTW, you'll want similar mirrors to help warm up up Mars

 

[Cathbadhian]

9-12 inches in 80 years!

Wow how can we ever cope with that?

Coastal cities will still be there. Most no one will notice.

Miami is already having issues with sinking land. New Orleans is under sea level. NYC flooded with superstorm Sandy. It's only going to get worse.

I live on a coast. I hike along it all year around, and I've seen flood walls go up, local fen land being restored and teeming with waterfowl, the steady erosion of sand dunes elsewhere, even threatening historical buildings.

12 inches of extra sea height will render those flood walls obsolete, the fens may flood permanently, and those sand dunes will be eroded much faster. Preventing all of that, if we let sea level rise too much, will require significant expenditure by local government (and from my taxes!).

I have to question if the original poster has ever spent time on a coastline, or has ever in fact considered how powerful the sea is before we decide to make it bigger!

 

[The Wonderful Wizard]

9-12 inches in 80 years!

Wow how can we ever cope with that?

Coastal cities will still be there. Most no one will notice.

Miami is already having issues with sinking land. New Orleans is under sea level. NYC flooded with superstorm Sandy. It's only going to get worse.

Remediation is either a fading dream or an active delusion.

Mitigation is all that's left.

The nation of Netherlands would like to disagree. Remember that time they recovered nearly half of their nation from the ocean starting the 1500s?

Let's not let gloom over global warming transform into a sense of helplessness and pretend like the only mitigation effort you can take is to stop dumping CO2 or simply die. You can in fact build sea defenses in many places, with a cities like New York being an obvious candidate for a place well worth defending from the sea rather than retreating from it.

I too want to reduce our CO2 emissions, and that certainly is the best solution, but I loath how the climate change movement has adopted an abstinence only approach to dealing with climate change, and get angry if someone suggests expresses any other opinion than totally helpless before changing climate.

Lots of places can't deal with a sea level rise and will have to evacuate before rising waters, but New York City is not one of those places, because we will defend it, as we are more than capable of doing.

I think that’s what he means by mitigation, as prevention (emissions restrictions and CCS) have failed for lack of political will.

 

[The Wonderful Wizard]

9-12 inches in 80 years!

Wow how can we ever cope with that?

Coastal cities will still be there. Most no one will notice.

The average elevation of Florida is 72 inches. Some places are 36 inches.

Yeah, wow, how could we ever cope with that? The lower parts of Florida have vast amounts of buffer height. I mean it would take another 2 rises of 12" before those parts are permanently underwater.

Why would Florida possibly have to worry about this in the future? They are already handling it. See with your own lying eyes!

PS: the worst case is 18", so there is also the part where you did not even read the whole article.

It seems like the risks in S. Florida are going to be "hidden" by the lunar nodal cycle for the next few years.

The lunar effect is currently in a downcycle, knocking about an inch (~2.5 cm) off high-tide levels over the coming 4 years.

The next peak is 2035, I'd place a bet on people freaking out by then. If I had Florida real estate I'd consider getting the hell out of there in the mid-2020s.

"Who's gonna buy it, fucking Aquaman?!?!"

Climate change deniers who can buy without a mortgage.

Of course, they won’t buy land in any of the poor suburbs, so if you own property there you’re screwed, but those in richer areas will be able to reduce their losses and those who own greenfield land near the suburbs might even make a profit.

 

[fcrary]

9-12 inches in 80 years!

Wow how can we ever cope with that?

Coastal cities will still be there. Most no one will notice.

Miami is already having issues with sinking land. New Orleans is under sea level. NYC flooded with superstorm Sandy. It's only going to get worse.

Remediation is either a fading dream or an active delusion.

Mitigation is all that's left.

The nation of Netherlands would like to disagree. Remember that time they recovered nearly half of their nation from the ocean starting the 1500s?

Let's not let gloom over global warming transform into a sense of helplessness and pretend like the only mitigation effort you can take is to stop dumping CO2 or simply die. You can in fact build sea defenses in many places, with a cities like New York being an obvious candidate for a place well worth defending from the sea rather than retreating from it...
Lots of places can't deal with a sea level rise and will have to evacuate before rising waters, but New York City is not one of those places, because we will defend it, as we are more than capable of doing.

Perhaps for New York City. But I can't Florida building a system of dikes and canals like those in Holland (which isn't the same as the Netherlands). Not to mention all the pumps required. At least the project doesn't seem viable. And the United States is much more lax about maintaining infrastructure than the Netherlands.

 

[numerobis]

Perhaps for New York City. But I can't Florida building a system of dikes and canals like those in Holland (which isn't the same as the Netherlands). Not to mention all the pumps required. At least the project doesn't seem viable. And the United States is much more lax about maintaining infrastructure than the Netherlands.

Much of Florida can't, because the ground is too porous. The faster they'd pump, the faster they'd undermine their sea walls.

 

[nocera]

1500-2000 years ago the ocean level was many feet higher than current levels. I think we'll be fine if it goes back to normal. It will cost a bit in infrastructure on some coastal communities, but I'm sure the feds will pass an infrastructure bill to take care of it. So, all good! There's really no reason to even talk or debate climate change, unless your one of the entities making money off of it to keep it in perpetual motion...

 

[nosmadar2016]

9-12 inches in 80 years!

Wow how can we ever cope with that?

Coastal cities will still be there. Most no one will notice.

Miami is already having issues with sinking land. New Orleans is under sea level. NYC flooded with superstorm Sandy. It's only going to get worse.

US Navy is working to reinforce / remediate infrastructure at Norfolk, VA naval base for exactly the same reason.

 

[Azethoth666]

I have a question about the flooding of the below sea level basins. How fast is the rebound in such a scenario? We are able to measure the effect of water in California in drought and non drought years. Does that help predict it? That is, how long before rebound pushes the land back up, and adds that entire volume to the whole flooding disaster as well?

Naively I expect it to be a slow process like continental drift, but faster than that because it's simple buoyancy?

It is a plate-tectonics-ish speed, but this is definitely an important consideration. It can displace water, it can also change the shape of the bed beneath the ice, how much of the ice is supported by floating, etc.

http://www.antarcticglaciers.org/glacie ... n-ice-age/
https://advances.sciencemag.org/content/7/18/eabf7787
https://www.nature.com/articles/ncomms9798

Interesting, one of those papers has an instantaneous rebound of 2" of sea level rise, followed by 2k years of extra stuff at tectonic rates. So it sounds like the bulk is slow, but 2" is not exactly nothing as the "immediate" response. Also it’s a decaying response so it’s front loaded in effect. 2k is not much solace if most of it is happening in the first few hundred years?

 

[Azethoth666]

9-12 inches in 80 years!

Wow how can we ever cope with that?

Coastal cities will still be there. Most no one will notice.

Every time people feel the need to speak and remove all doubt about their powers of understanding the way you do, I point them in the direction of insurance premiums in the affected areas.
We are at a point where opening a business in some coastal locations might not be viable because insurance is simply too expensive - if you manage to get it at all.
Educate yourself.

That is a pretty interesting economic signal. Insurance runs on actual actuarial fact, not political fiction.

It reminds me of a similar signal in the automotive world: investment. It dried up for ICE car parts makers back in 2016 already. All the German auto makers have already come together to hash out a survival strategy for some parts makers so they can service the current and future ICE cars until end of life.

tl;dr Global warming consequences are already here and causing economic change.

 

[Azethoth666]

Perhaps for New York City. But I can't Florida building a system of dikes and canals like those in Holland (which isn't the same as the Netherlands). Not to mention all the pumps required. At least the project doesn't seem viable. And the United States is much more lax about maintaining infrastructure than the Netherlands.

Much of Florida can't, because the ground is too porous. The faster they'd pump, the faster they'd undermine their sea walls.

I cannot find it right now but I saw a great Florida documentary on sinkholes and the underwater caves.

Essentially there are vast and long underwater cave systems running all over the place. With a tiny layer of earth on top that we build on. From time to time we are unlucky and there is a collapse and we lose some cars and or houses and or people into them. Cave divers have explored some that go on for miles and miles. Yep, a 72" high swamp is not a lot of land, and water barriers will have to both go up, as well as down to some kind of bedrock to do their job.

 

[numerobis]

Perhaps for New York City. But I can't Florida building a system of dikes and canals like those in Holland (which isn't the same as the Netherlands). Not to mention all the pumps required. At least the project doesn't seem viable. And the United States is much more lax about maintaining infrastructure than the Netherlands.

Much of Florida can't, because the ground is too porous. The faster they'd pump, the faster they'd undermine their sea walls.

I cannot find it right now but I saw a great Florida documentary on sinkholes and the underwater caves.

Essentially there are vast and long underwater cave systems running all over the place. With a tiny layer of earth on top that we build on. From time to time we are unlucky and there is a collapse and we lose some cars and or houses and or people into them. Cave divers have explored some that go on for miles and miles. Yep, a 72" high swamp is not a lot of land, and water barriers will have to both go up, as well as down to some kind of bedrock to do their job.

The limestone is hundreds of meters deep. Easier than putting in extremely tall underground foundations around the cities: build artificial islands. Basically, boats with cities on top.

And by easier I mean Florida is fucked.

 

[Toastr]

I think it's good to have a range of plausible scenarios for how much sea level increase we could expect under the most likely range of scenarios, but one scenario that I don't see highlighted often enough is basically the worst case scenario that I don't think many people are aware of. If we ignore global warming entirely and just let the temperature keep rising, what happens when ALL of the ice caps melt?

That's more or less what the RCP8.5 scenario in the article is: a worst-case scenario. It's named that because it's based on 8.5° C of warming, which is basically what we'd expect if emissions continued to rise throughout the next century with zero mitigation. As the article mentions, the uncertainty is pretty huge, but even based on that RCP8.5 scenario (bottom right graph) there's basically no chance the ice caps will melt entirely in the next century (or even the next three centuries).

That said, you're right that if all the Antarctic and glacial ice in the world did melt entirely there would be roughly 70 meters (230 feet) of sea level rise.

RCP8.5 is not "8.5" degrees warming. It's "end-of-century radiative forcing of 8.5 watts per metre squared – W/m2 – forcing increase relative to pre-industrial conditions".

Oops, that's on me. I fixed my post, thanks for the correction!

 

[Northbynorth]

1500-2000 years ago the ocean level was many feet higher than current levels. I think we'll be fine if it goes back to normal. It will cost a bit in infrastructure on some coastal communities, but I'm sure the feds will pass an infrastructure bill to take care of it. So, all good! There's really no reason to even talk or debate climate change, unless your one of the entities making money off of it to keep it in perpetual motion...

You forgot the /s ?

I guess you mean areas that was below the ice during the last Ice age? They have continued to rebound significantly the last 1000 years. Otherwise the oceans have been very stable the last millenium (like +/- 5cm) until the rising trend the last 100 years.

During the ice ages and between, 100+ meter changes were regular.

You are certainly right - It is not the the changes themselves that are the problem.
But our civilization struggle to deal with it. We have built an infrastructure and a global network that very badly deal with significantly changes in sea level, climate and ecosystems (we are extremely dependent on just a handful of crops).

Edit: Spelling, wording

 

[RobStow]

I have a question about the flooding of the below sea level basins. How fast is the rebound in such a scenario? We are able to measure the effect of water in California in drought and non drought years. Does that help predict it? That is, how long before rebound pushes the land back up, and adds that entire volume to the whole flooding disaster as well?

Naively I expect it to be a slow process like continental drift, but faster than that because it's simple buoyancy?

I can't give you exact figures for how fast the rebound would be, but Canada is still rebounding from the last ice age.

The area around Lake Dubawni (approx 63 N, 101.5 W) has the fastest post-glacial rebound on the planet. A mind boggling 17 mm per year. I find it hard to wrap my head around the idea of ROCK being able to do that. Almost as hard to fathom as the amount of ice it would have taken to depress that area in the first place.

 

[RobStow]

Slightly off topic, but has anyone determined the effect on Earths rotational speed from transferring the ice mass from the poles to being spread over the ocean surfaces?
How many seconds could be added to each day?

Within the last couple of weeks I read an article about how the loss of ice in Greenland is causing a very small but still measurable change in the axis of rotation but I can't remember if it said anything about effects on the speed of rotation.

The Greenland ice sheet is a large mass that is well off of the current axis of rotation. When water from melted ice runs off into the ocean it reduces the size of that solid off-axis mass and gets more or less uniformly distributed around the axis of rotation.

 

[Snark218]

1500-2000 years ago the ocean level was many feet higher than current levels. I think we'll be fine if it goes back to normal. It will cost a bit in infrastructure on some coastal communities, but I'm sure the feds will pass an infrastructure bill to take care of it. So, all good! There's really no reason to even talk or debate climate change, unless your one of the entities making money off of it to keep it in perpetual motion...

“A bit of infrastructure?” You’re fuckin’ delusional.

 

[Rindan]

9-12 inches in 80 years!

Wow how can we ever cope with that?

Coastal cities will still be there. Most no one will notice.

Miami is already having issues with sinking land. New Orleans is under sea level. NYC flooded with superstorm Sandy. It's only going to get worse.

Remediation is either a fading dream or an active delusion.

Mitigation is all that's left.

The nation of Netherlands would like to disagree. Remember that time they recovered nearly half of their nation from the ocean starting the 1500s?

Let's not let gloom over global warming transform into a sense of helplessness and pretend like the only mitigation effort you can take is to stop dumping CO2 or simply die. You can in fact build sea defenses in many places, with a cities like New York being an obvious candidate for a place well worth defending from the sea rather than retreating from it.

I too want to reduce our CO2 emissions, and that certainly is the best solution, but I loath how the climate change movement has adopted an abstinence only approach to dealing with climate change, and get angry if someone suggests expresses any other opinion than totally helpless before changing climate.

Lots of places can't deal with a sea level rise and will have to evacuate before rising waters, but New York City is not one of those places, because we will defend it, as we are more than capable of doing.

I loath idiots who think engineering a band-aid is preferable to engineering prevention.

Good thing I literally never suggested that.

 

[Properjob70]

9-12 inches in 80 years!

Wow how can we ever cope with that?

Coastal cities will still be there. Most no one will notice.

Miami is already having issues with sinking land. New Orleans is under sea level. NYC flooded with superstorm Sandy. It's only going to get worse.

Remediation is either a fading dream or an active delusion.

Mitigation is all that's left.

The nation of Netherlands would like to disagree. Remember that time they recovered nearly half of their nation from the ocean starting the 1500s?

Let's not let gloom over global warming transform into a sense of helplessness and pretend like the only mitigation effort you can take is to stop dumping CO2 or simply die. You can in fact build sea defenses in many places, with a cities like New York being an obvious candidate for a place well worth defending from the sea rather than retreating from it.

I too want to reduce our CO2 emissions, and that certainly is the best solution, but I loath how the climate change movement has adopted an abstinence only approach to dealing with climate change, and get angry if someone suggests expresses any other opinion than totally helpless before changing climate.

Lots of places can't deal with a sea level rise and will have to evacuate before rising waters, but New York City is not one of those places, because we will defend it, as we are more than capable of doing.

The sea level rise will inundate low-lying lands like the Netherlands. They've never dealt with significant sea level changes. All they did was put up dykes and pump out the water. The hydraulic forces remained stable throughout their history, meaning the effects of the ocean being kept at bay remained the same.

This won't happen with sea level rises.

The static nature of the forces will change to dynamic, and increasing. That will have a direct, and increasing, impact on the erosion levels of the dykes, the ground water quality, the impacts of storm surges and tides and the costs associated with keeping the water at bay.

To illustrate the point, you can think of the Netherlands as a weak water hose with a restricted outlet. The amount of water flowing through it is constant. But increase the amount of water and the outlet prevents that from escaping. It's not a matter of "more pumps". It's a matter of hydraulic pressure on the ground surfaces and footings of the dykes and passive flood control measures. Eventually, the amount of water pressure on the hose is too much, and the hose breaks.

Exactly where that point is can probably be calculated, but I don't have the figures or variables to do that. It's just that water pressure through soil and rock increases, especially when the water is above that soil and rock pressing down on it.

But assuming it's actually technologically possible to defy significant sea level increases with dykes and such, the costs would be prohibitive, and the consequences of a failure of that technology beyond catastrophic.

So while I won't rule out the possibility, extremely remote, given today's level of technology, to apply a technological fix to rising sea levels for low-lying parts of a country, the costs of doing that will not be affordable for any country. Tidal wave barriers don't expect to keep back water indefinitely, and are extremely expensive to build (not to mention, due to the carbon released from concrete, exceptionally bad for reducing carbon emissions), and they're the closest things to a partial fix that mankind has today. Earthen barriers will crumble or erode. There's not enough steel in the world to withstand salt water long enough to do the job.

The only viable, affordable, and practical means to deal with the issue is to move the damned cities to higher ground. If that means moving a country inland, or seeing it disappear forever (or at least until the next ice age), then relocation of the population is all that's left.

We are at the point where mitigation won't keep global temperatures below the Paris Accords levels, and 3C by the end of the century is now considered inevitable (pending the creation of some really radical, and effective, atmospheric carbon reduction tech that isn't there yet, and even that may not be enough with climate inertia being a thing). Adaptation is necessary already, and the need for that is growing daily. That's not building taller dykes. That's relocating cities away from coastlines and allowing the seas to swallow what we once walked upon, and learning from our mistakes.

There are even disaster mitigation scenarios being considered that propose walling off the whole North Sea - considered meaning in both technological & cost benefit terms

https://www.weforum.org/agenda/2020/08/ ... ea-levels/

 

[fcrary]

Slightly off topic, but has anyone determined the effect on Earths rotational speed from transferring the ice mass from the poles to being spread over the ocean surfaces?
How many seconds could be added to each day?

Within the last couple of weeks I read an article about how the loss of ice in Greenland is causing a very small but still measurable change in the axis of rotation but I can't remember if it said anything about effects on the speed of rotation.

The Greenland ice sheet is a large mass that is well off of the current axis of rotation. When water from melted ice runs off into the ocean it reduces the size of that solid off-axis mass and gets more or less uniformly distributed around the axis of rotation.

You made me work out the numbers. The East Antarctic ice sheet has a mass of 2.6x10¹⁹ kg, and it's close enough to the pole that it doesn't contribute to the Earth's angular momentum. If it were to melt and be spread evenly around the world, it would basically add 2/3 M_EAI R_E² to the Earth's angular momentum. Which is currently 0.33 M_E R_E². That's about one part in 100,000. So we could see a 10^-5 drop in the Earth's rotation rate. Call it five minutes per year. Which is quite a bit more than I expected.

 

[graylshaped]

9-12 inches in 80 years!

Wow how can we ever cope with that?

Coastal cities will still be there. Most no one will notice.

Miami is already having issues with sinking land. New Orleans is under sea level. NYC flooded with superstorm Sandy. It's only going to get worse.

Remediation is either a fading dream or an active delusion.

Mitigation is all that's left.

The nation of Netherlands would like to disagree. Remember that time they recovered nearly half of their nation from the ocean starting the 1500s?

Let's not let gloom over global warming transform into a sense of helplessness and pretend like the only mitigation effort you can take is to stop dumping CO2 or simply die. You can in fact build sea defenses in many places, with a cities like New York being an obvious candidate for a place well worth defending from the sea rather than retreating from it.

I too want to reduce our CO2 emissions, and that certainly is the best solution, but I loath how the climate change movement has adopted an abstinence only approach to dealing with climate change, and get angry if someone suggests expresses any other opinion than totally helpless before changing climate.

Lots of places can't deal with a sea level rise and will have to evacuate before rising waters, but New York City is not one of those places, because we will defend it, as we are more than capable of doing.

I loath idiots who think engineering a band-aid is preferable to engineering prevention.

Good thing I literally never suggested that.

Pity Fatesrider already demolished your entire pretense that we could stave off geological forces for long without addressing the root cause--and maybe not even then.