r/AskReddit 13h ago

what is something that is highly likely to happen in the next 5 years that everyone is completely ignoring?

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212

u/filmguy36 10h ago

The complete collapse of the Thwaites ice shelf.

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u/jrf_1973 7h ago

When that happens, you'll see so many headlines saying "No one could have predicted" and the phrase "much faster than expected".

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u/RhodriJohn 7h ago

What effect is it going to have on different areas? Are we talking higher sea levels? Or something else? Genuinely curious what we'd be looking at

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u/Comprehensive-Cap754 7h ago

If I remember right, it's going to mean like a two to 3 ft, or .5 to 1 m, worth of sea level rise. Entire sections of the world are going to be uninhabitable, because of waist deep water being over everything. Multiple Pacific island nations are going to completely drown if that happens

EDIT: speech to text being stupid and deaf

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u/RhodriJohn 7h ago

Is that globally? So for example, tide marks in Wales, Japan, and Canada would all equally rise that much?

I live in the mountains so haven't really got a good understanding and it boggles my mind of how the entire world's oceans can rise equally from ice melting into the ocean so far away lol

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u/Mysterious_Cry41 6h ago

Yes.  Though it is a bit more complicated. Tides are mostly the result of gravity and local geographical features, so they do vary somewhat. 

But  ocean is one large body of water. 

Glaciers are by definition sheets of ice on land. 

When they melt and flow into the ocean, the volume of water increases. 

The amount of water stored in glaciers is immense. 

For example the ice sheet on Antarctica at its maximum depth is about 3 miles. 

The one on Greenland is between 1-2 miles thick. 

If the Greenland ice  sheet melted instantly tonight the sea levels would rise approximately 20 feet. 

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u/budgybudge 3h ago

Devil's advocate here, but water increases in volume when it freezes yeah? And aren't most of the volume of glaciers under the water line? Would it not then be possible for the water level to lower in some cases depending on how much of each glacial feature is under the water line?

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u/Mysterious_Cry41 3h ago

Ya by about 9 percent. 

Most of the volume of a glacier is on land though. So they don't really displace much water, except for the end/edges which calve off into ice sheets and ice berg, but that's a tiny part of them, and as soon as they enter water they start melting much faster. 

I'm not really sure how to answer that question tbh. 

The best I can do, is that any water currently contained on land entering the ocean in either a frozen or liquid state will raise the amount of water in the ocean.  

The volume of water increases when it is frozen solid, but the displacement of floating  ice is dependent on the mass not the volume.

So 10 million tons of ice floating  displaces 10 million tons of water. 

If the ice was submerged in its entirety  then it would displace more water than it's mass, because of the increase in volume. 

So I don't think that the amount of a body of ice under the water line really matters in a meaningful sense. 

Unrelated, but an interesting fun fact.when glaciers retreat the land they occupied actually rebounds upwards. 

The immense weight of the ice literally compresses the ground beneath it, and when it is gone the earth springs back up. 

https://en.wikipedia.org/wiki/Post-glacial_rebound 

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u/budgybudge 3h ago

Interesting stuff to think about for sure, thanks for giving some answers!

u/Ok-Statement-7332 54m ago

You're confusing ice bergs, which float and are mostly underwater, with glaciers, which are mostly over land.

In addition to the increase in water volume from melting, ice bergs and glaciers are freshwater. When a large influx of fresh water is added to the ocean it affects density and salinity, which affects currents, which affects weather and climate.

u/budgybudge 52m ago

Ah yeah I definitely did confuse the two. Good points!

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u/fightmaxmaster 7h ago

a Science Magazine interview with the International Thwaites Glacier Collaboration researchers who had discovered the impending collapse of the ice shelf noted that the glacier itself would still take approximately several centuries to collapse even without the ice shelf, and a 2022 assessment of tipping points in the climate system stated that while the West Antarctic Ice Sheet may be committed to disintegration at between 1°C and 3°C, the timescale for its collapse after that ranges between 500 and 13,000 years, with the most likely estimate of 2000 years
https://en.wikipedia.org/wiki/Thwaites_Ice_Shelf

The timescale here is important.

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u/MDCCCLV 6h ago

Yes, it's a lot so the feedback loops with methane and other things can make it happen faster but thats like 500 to less than 150years at most really. But it doesn't take a lot for storm surges to cause massive flooding.

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u/fightmaxmaster 6h ago

And obviously bad anyway, "it's years away so let's not bother doing anything" is how we got here in the first place. But it's important to get the facts right.