Unavoidable future increase in West Antarctic ice-shelf melting over 21 century

https://www.nature.com/articles/s41558-023-01818-x

69 42 3 years ago

anotherhue• 3 years ago

These results suggest that mitigation of greenhouse gases now has limited power to prevent ocean warming that could lead to the collapse of the West Antarctic Ice Sheet.

thecrumbles• 3 years ago

Apologies in advance for a low-effort hot take:

Its growing abundantly clear that the tipping point is well in the past.

Decarbonization must proceed, of course, but if we can't feasibly remove carbon from the system at scale, we're well and truly fucked.

bryanlarsen3• 3 years ago

Fucked is not a binary. The choice now is between majorly fucked and severely fucked.

quickthrower22• 3 years ago

Severely fucked is human extinction?

fsloth• 3 years ago

Might need to do a bit of geoengineering on the side. I hear upper atmosphere SO2 does wonders for atmospheric cooling (and yes, Neal Stephenson has written a book about it).

Apologies for the slightly dark take. But either it’s humor or despair and I refuse to choose the latter out of principle.

stevenwoo2• 3 years ago

It's a terrible, interesting time we are leaving our collective children and grandchildren. There will have to be a mass migration, where possible, since so many people live or work within that zone of sea water rise.

They also need to adjust this map viewer thing to go to 20 feet.

https://coast.noaa.gov/slr/

monkeycantype• 3 years ago

my hometown is so low the contour maps have no contour lines on them. I've recently heard neighbours chatting about not being able to afford flood insurance. I have friends who still believe climate change is an academic ploy for funding liberal universities - given our barely higher than high tide elevation, I understand the longing in their denial. Jacked premiums are the first event I've encountered that moves acknowledgement/denial of global warming from a lifestyle/personal identity choice into unignorable.

Podgajski3• 3 years ago

The focus on sea level rise is a huge mistake. We need to be focusing on what this is going to do in terms of food production. People will be more alarmed from starvation than having to move away from the coast.

treypitt• 3 years ago

Tipping points and feedback loops are meaningless to techno-utopians, in their eyes nothing is fundamentally different between climate change and other technical challenges in the past

dlevine• 3 years ago

Additionally, even if we could remove carbon from the system scale, it's not like everything would magically reset to where it was. We are seeing changes (e.g. extinctions) that aren't really undoable.

With that said, I'm sure that some of the damage can potentially be reversed, and the planet has some capacity to self-heal over long periods of time.

Hopefully reducing emissions and even partial decarbonization will lead to a less bad outcome in the medium to long-term.

shrimp_emoji• 3 years ago

How do you know what signs represent post-tipping point and what don't? It would take some heavy duty physics and meteorology to know one way or the other, no?

hotpotamus2• 3 years ago

Living in South Texas it sure feels like something changed this year; I've never seen so many trees die.

If we are unable to determine the point of no return, then perhaps that would be good reason to stop changing the carbon content of the only planet we can occupy, but I have also come to believe that the changes to come are inevitable and likely terrible.

raffraffraff• 3 years ago

I got accused of being a Luddite because of my (negative) response to a post about SpaceX launching rockets every 2.5 days. There are reasons, beyond being a Luddite, for being against such enterprises.

Podgajski3• 3 years ago

People telling me I’m a Luddite is just making me more and more of a Luddite.

bryanlarsen3• 3 years ago

Elon promised to switch to a carbon-neutral fuel (methane synthesized from atmospheric carbon). It'd be nice if some agency actually held him to that promise.

gehwartzen2• 3 years ago

Whenever I think of Geo-Engineering I imagine someone getting into keeping reef aquariums, noticing some fish are looking less than healthy, testing and seeing chemical/physical properties of the tank are off, adjusting by adding/removing some chemical only to see everything die anyway, and then coming to the realization that maybe this hobby is a lot more nuanced then they imagined and isn’t for them.

Perhaps next time we’ll just get a freshwater planet, I hear those are much more forgiving ;)

bestouff• 3 years ago

I don't understand this US mentality that some more tech will save us. It's some some of blind headlong rush to our demise, just to ignore the fundamental problems:

- too many humans

- too much pollution

- too much energy consumption

tarkin2• 3 years ago

Doom-mongering--correct or not--doesn't add to the debate.

zuzu89• 3 years ago

What makes these new projections different from those of recent decades?

coolhand2120• 3 years ago

It has been hypothesized that Amundsen Sea warming will respond to future climate change and may be amenable to mitigation by reducing greenhouse gas emissions6,9,10. However, this hypothesis has not been adequately tested. Existing future projections of ice-shelf basal melting are generally not reliable in the Amundsen Sea, a region which is frequently biased cold or poorly resolved in the underlying ocean models11,12. Reference 13 produced the first future projections using a regional model of the Amundsen Sea, which simulated an increase in basal melting. However, this study only considered a single forcing scenario, the worst-case scenario of extreme fossil fuel use, and did not account for internal climate variability.

If you were to say "they have just decided to go with the most alarming scenario possible and throw the scientific method to the wind" I think it would fit the description in the abstract.

mistrial9• 3 years ago

measurements

mjhay• 3 years ago

I'm not familiar with the latest research, but the WAIS has long been recognized as the biggest potential contributor to severe sea-level rise due to the marine ice-sheet instability, which it is uniquely vulnerable to.

Ice sheets are basically big domes of ice that flow outward under their own weight. Little surface melt occurs in Antarctica, while snow continues to fall. To maintain approximate mass balance, most of the mass is lost to the ocean. Most of the WAIS bed is below sea level, but the ice is thick enough that the ice rests on the bed, and seawater is excluded. Where the ice sheet begins to float is where ice shelves or calving happens. Towards this margin, the outlet ice streams are almost but not quite floating. They have little friction at their beds, but they push up sediment in front, forming sediment wedges that push back on the grounded ice behind them. This slows the outward flux of ice, and creates a stable equilibrium as the ice pushes up against the wedge.

Much of WAIS is on a reverse bed, where the bed drops in elevation as you proceed inland (despite the ice getting thicker, and the top of the ice sheet getting higher and higher). Due (largely) to increased submarine melting leading to thinner ice shelves (which themselves push back due to pressing up against islands and such), the ice grounding line can retreat from the wedge. Worse, this enters a feedback: due to the reverse bed, the ice is now thicker in the new retreated grounding line, because flotation occurs in deeper water. This increases ice flux due to the thicker front. Thus retreat accelerates more, and so on until the ice sheet collapses.

joak• 3 years ago

The conclusion: policymakers should be prepared for several metres of sea-level rise over the coming centuries. [...] Limiting the societal and economic costs of sea-level rise will require a combination of mitigation, adaptation and luck.

cozzyd• 3 years ago

I guess NYC, Boston, SF etc. better start building their sea walls...

euroderf• 3 years ago

Built for you by... Halliburton.

ben30• 3 years ago

An Antarctic ice melt leading to a 5m global sea-level rise would render London's Thames Barrier obsolete. We're talking about a threat that could manifest by 2050 if climate targets aren't met. The engineering challenge to upgrade or replace the barrier is colossal, think at least £10 billion just for the engineering, not factoring in the social costs.

Add land acquisition in London's expensive real estate market, and the relocation of communities, you could easily double or triple that cost. To put it in perspective, this could rival or surpass projects like the Channel Tunnel in terms of financial and logistical complexity.

And yet, there's a startling lack of political and public dialogue on this urgent issue. This isn't just about engineering; it's about national security and public safety. The disconnect is alarming.

Unavoidable future increase in West Antarctic ice-shelf melting over 21 century

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