[lifeisstillgood]

A big tangent but I remember a podcast with Sir David King, UK chief scientific advisor

- So, Sir David, what's worries you most?

- The Greenland Ice Sheet. If it melts human civilisation is finished.

- oh. And err is it melting?

- Yes, and accelerating.

- Oh.

[wiremine]

I couldn't find the original source, but here's a link that mentions the comment. Anybody have the original source?

https://physicstoday.scitation.org/do/10.1063/pt.5.020563/fu...

[pmastela]

Could you elaborate as what about the melting of the Greenland Ice Sheet was concerning to Sir David King? Is it the mercury that is released or the rising sea levels it will cause or something else?

[splittingTimes]

IIRC, when sheet melts, it will release a huge amount of fresh water into the salty Atlantic gulf stream and shut it down. The convection from top warm water sinking into the depth because of a salt concentration gradient will stop functioning.

Besides it's climate impact and heat transfer mechanism it will likely disturb the other ocean currents that are import for a stable climate as well.

[AstralStorm]

Predicted results are huge acceleration of global warming as albedo is decreased and water absorption of GHG is decreased due toreduced mixing. Plus some rather big local climate changes earlier than that.

Easily getting us to the edge of what is livable even with advanced technology.

[gspr]

7 meter rise. If that happens, we're toast.

Yes, an Antarctic melt would be worse, but it's far less likely.

[barbacoa]

Humans have experienced 120m sea level rise since the last ice age. We can only hope this last 7m wont finish us off.

[dragonwriter]

> Humans have experienced 120m sea level rise since the last ice age.

Human civilization didn’t, because human civilization didn’t exist at the last glacial maximum, and almost all of that rise was before human civilization existed. Low density nomadic hunter-gatherer existence is less disrupted by sea level change than settled agriculture and industry.

[fogihujy]

It's not about the survival of Humanity, but rather about global trade disruptions, mass-migrations, and massive property damage on a scale we've never seen. Humanity will be fine, but if it goes really bad then it will cause a lot of suffering and it may take centuries to recover.

[gooseus]

And the third order effects will be further destabilization leading to more wars, which may go nuclear, and will all feed back into more environmental degradation.

[PicassoCTs]

So, if i were to write a algorithm, that determines the new shoreline - and buys property there, i could profit from this when?

[jfengel]

It doesn't work like that. We don't get a new shoreline miles away.

What we get is every single existing ocean port city (which is a lot of the largest cities) being threatened by more frequent flooding. They're all right at sea level, because that's where you build port cities. Not all of these cities really depend on being ports any more, but that's how they became major population and business centers.

They don't just pick up and move something like that. There's no place you can say, "Oh, they're going to move New York over to X, so I'll buy land there now". Even if they did for some reason decide that it was so bad they had to abandon New York (or Charleston or San Francisco or lots of others), there's no one place that it goes. The whole human geography of it changes.

[ceejayoz]

Property rights tend to require a functional society to effectively utilize.

[drknownuffin]

Now. There are already hedge funds purchasing land based on this idea.

[SketchySeaBeast]

While that's true, we didn't have as many major centers with permanent buildings set up. I'm looking for data, but I imagine that places like New York would be underwater, would they not?

[Ekaros]

Places like NY would likely spend couple billions to invest on dykes and then sell it as new water front property...

[supercheetah]

Which would get more and more expensive to maintain every year, and if maintenance stops, that would be really, really bad news.

[barbacoa]

Sea level rise is measured at 3.5mm/yr[1] as of 2016 so at current rate it will take 2000 years to hit 7m. NYC may be underwater but it would in all likelihood be as irrelevant to the future as Tyre or Carthage is today.

[1]https://ocean.si.edu/through-time/ancient-seas/sea-level-ris...

[ninju]

The concern is the acceleration of the sea level rise

"Whether it takes another 200 or 2000 years largely depends on how quickly the ice sheets melt. Even if global warming were to stop today, sea level would continue to rise."

-- from the same article (2 sentences later)

[jl6]

Did he explain why?

[samatman]

Estimates of total Greenland contributions to sea-level rise by 2100 range from a low of 2.1cm to a high of 5cm.

I'm going to choose to worry about other things.

https://www.carbonbrief.org/new-climate-models-suggest-faste...

Those of you downvoting me to banish your anxiety should find a healthier outlet for your issues.

[cjsplat]

Thank you for sourcing your data!

That carbonbrief article links to the underlying paper at : https://www.nature.com/articles/s41467-020-20011-8

The paper reports on an update of previous studies, and the results are reported mainly as changes from the previous material to reflect the impact that changes in the modelling decisions.

I can't tell where the 2.1 cm to 5 cm numbers come from (searching the paper for "2.1" is interesting).

Here is a table from the paper reported as total sea level impact estimates and 1 stddev range, rather than deltas : https://www.nature.com/articles/s41467-020-20011-8/tables/1

It reports the expected 2100 see level rise from Greenland ice melt of 6 different scenarios, in two methodologies. The low, low stddev at 3.7 cm, and the high, high stddev at 25.6 cm.

And of course sea level may also be rising from other sources, that just isn't covered in the paper you mention.

You get to pick your personal items to worry about based on your individual assumptions and interests, but if your opinion is based in part on that specific paper you might want to reread it.

[ska]

I'm not sure where you got those. IPCC 2019 report estimated the Greenland contributions in the 10-30cm range, and the link you gave is mostly about newer models suggesting a bit higher than 2019 IPCC, so suggest at the higher end (or above) of that range.

The only related thing I could find in your linked report was to estimate contributions up by 2.6cm/2.8 cm/5cm (different scenarios) from CMIP5 to CMIP6, not in total. Maybe I missed something?

[bregma]

Yes, but up to 7 m over the next 200,000 years. You might want to short boardwalk futures.

[uncoder0]

My investment horizon doesn't stretch out 200k years as I don't have dynastic wealth so I'll pass on that advice.

[ninju]

The article does not mention 200,000 years. It calls out concerns by the end of the 21 century...which is only 80 yrs away