Global Climate Disruption.

[Ironside]

No it doesn't, as ice has more volume than water the submerged ice melting will lower the water level.

Indeed, ice has more volume. And that extra volume is the thing sticking up above the water surface. Take 1 kg (1L) of water, freeze it (roughly 1.1L). The ice cube will float, but also displace 1 kg (1L) of water. This is one version to weight things less dense than water. If an object becomes completely submerged (by weight or force) the you get its volume, by the displacement of water.
Melting completely submerged ice would lower the water level, but it would require something to keep the ice from floating up.

Missed this, 31cm in a centuryy for whatever reason, to even consider a rise of 40 meters, doubt there even exists enough water to raise the sea by just one sorry meter. How. From where

The worser scenarios are about 0.5-2 meters in a century.

Antartica contains ice equivalent to about a 60 meter water rise.

Greenland about 7 meters.

And yes, melting all of it would take thousands of years.

Land bound or bottom frozen (with abundant ice above sea level) regions are those that increases the sea level. It's the same principle that made the water level more than 100 meters lower than today during, the ice ages.

And for the fun of it. Fragony, the only relevance the depth has, is that increased water temperature increases the volume of water. It's very minor, but on 4 km (estimated average water depth) of water it makes a difference. Going from 4 C water to 30 C would cause a sea level rise of 17 meters. I doubt this factor is going to matter much normally (an average sea temp of 30 C is proably a half desert Earth or something like that), but it exists.

[Fragony]

'Antartica contains ice equivalent to about a 60 meter water rise.Greenland about 7 meters.'

So they say but it's impossible when you think of it. Take it's volume and the volume it would require to even raise it with just one meter. Absolute bull that sea levels can rise 7, or even 60 meter, they may say so but that doesn't make it true, calculare it for me and i will listen

[Nowake]

What’s so difficult about it?
It's an elementary school problem.


You convert the ice volume of the ice sheets into the water volume it would create.
The volume of Antarctica’s ice is 29,315,965 km³.
Now, of course, we have different densities. Specifically, because of the various gasses trapped within it, ice is about 90% as dense as water – hence a 0.9 conversion rate.
Thus the volume of said water is 29,315,965 x 0.9 = 26,384,368 km3.


Now, you take your newfound water volume of the ice sheets and divide it by the total surface area of the oceans, which is 346,976,563 km².
You now have 26,384,368 km3 / 346,976,563 km² = 0.0760 km = 76m.
Basic arithmetic.


I suppose they come up with only 61 meters because there are a few independent atmospheric variables which intervene to lessen the impact.

[drone]

What’s so difficult about it?
It's an elementary school problem.

Actually, it becomes a very difficult calculus problem. Since water does not stack, knowing the total volume of water released from the melt only gets you half way. The percentage of the earth's surface covered with water will change as the volume of water increases, in a very not-easily-computable way. How much coastline and brackish riverbank gets eaten with a 20 meter rise in water levels? 30 meters? They have computer models for it, it is not as easy as you make it out to be.

[Tellos Athenaios]

It doesn't but the same holds true for ice as well at those volumes. Given the height of the ice sheets even in terms of order of magnitude this is a non-trivial volume as well.

[Nowake]

@drone
It is already accounted for


Vertically, as I show above, you obtain 76m.
70-75% of the earth is already covered in water.
It appears to me that this, combined with the atmospheric variables I was mentioning above, makes the 61m they are advancing as a figure just about right.


Perhaps it's not 61, perhaps it's 59, or 55, but easily above the 40m figure they were debating about? Definitely.

[Ironside]

Actually, it becomes a very difficult calculus problem. Since water does not stack, knowing the total volume of water released from the melt only gets you half way. The percentage of the earth's surface covered with water will change as the volume of water increases, in a very not-easily-computable way. How much coastline and brackish riverbank gets eaten with a 20 meter rise in water levels? 30 meters? They have computer models for it, it is not as easy as you make it out to be.

10%-20% margin error on quick calculations is usually close enough to be acceptable. If you're toying with really large numbers, a factor 100 is still a small error.
Yes, the good calculations takes that into consideration and as Nowake already displayed, is already considered in the given calculations.

[drone]

But it's not an elementary school problem.

[a completely inoffensive name]

But it's not an elementary school problem.

Pssshhhh, I was calculating this kind of stuff in 5th grade.

[Tellos Athenaios]

Why not? In heavily simplified terms which serve only to illustrate orders of magnitude:

~71% of the earth's surface area is covered by ocean so assuming that we can just stack water vertically what would a 60m increase entail? Well, the 6.4km radius of the earth implies that the volume required would be something in the order of magnitude of: 7,1 * 6,0 * 4 * pi* (6.4*10^3)^2 m^3 = 2.2*10^10 m^3 in liquid water.

So what is Antarctica's surface area, then? According to the wiki, that is 14 million square kilometer, i.e. 14 *10^3 *10^3 m^2. Therefore if all that area was, on average covered with just 1m thick layer of ice what do we have: 1,4* 10^7 m^3. So how thick are these ice sheets apparently?

Well according to teh wiki 98% of that surface area is covered by layers of ice averaging at least a mile in height (1.6*10^3m). So using similar simplified calculation that yields a volume of: 1,4*10^7 * 0,98 *1.6*10^3 = 1.4*1.6*0.98 * 10^10 = 2.2*10^10 m^3 in ice... As a lower bound... Looks familiar?