Antarctica's 'Doomsday Glacier' Began Melting In Mid-20th Century, Study Finds (thehill.com) 60
According to a new study published in the journal Proceedings of the National Academy of Sciences, West Antarctica's Thwaites Glacier began rapidly receding in the 1940s -- much earlier than scientists had previous thought. The Hill notes that it's often referred to as the "doomsday glacier" due to the potentially catastrophic consequences of its hypothetical collapse. From the report: While scientists had already observed the glacier's accelerated retreat by the 1970s, they did not know when it began. Coupled with earlier research about Thwaites's neighboring Pine Island Glacier, the study also provides new, potentially alarming, insight into the cause of the glacier's melting. Scientists tried to reconstruct the glacier's history using analysis of the marine sedimentary record, and they found the Thwaites and Pine Island glaciers both lost contact with the seafloor highs in the 1940s -- at around the same time. These significant changes happened against the backdrop of a massive El Nino weather phenomenon, the scientists found, showing the glaciers "were responding to the same driver(s)."
"The synchronous ice retreat of these two major ice streams suggests that, rather than being driven by internal dynamics unique to each glacier, retreat in the Amundsen Sea drainage sector results from external oceanographic and atmospheric drivers, which recent modeling studies show are modulated by climate variability," the study read. The scientists note that the glaciers' continued retreat shows how difficult it can be to reverse some of the consequences of naturally occurring weather events -- which they say is made even more difficult by human activity. "That ice streams such as Thwaites Glacier and Pine Island Glacier have continued to retreat since then indicates that they were unable to recover after the exceptionally large El Nino event of the 1940s," the scientists wrote. "This may reflect the increasing dominance of anthropogenic forcing since that time but implies that this involved large-scale, in additional to local, atmospheric and ocean circulation changes."
"The synchronous ice retreat of these two major ice streams suggests that, rather than being driven by internal dynamics unique to each glacier, retreat in the Amundsen Sea drainage sector results from external oceanographic and atmospheric drivers, which recent modeling studies show are modulated by climate variability," the study read. The scientists note that the glaciers' continued retreat shows how difficult it can be to reverse some of the consequences of naturally occurring weather events -- which they say is made even more difficult by human activity. "That ice streams such as Thwaites Glacier and Pine Island Glacier have continued to retreat since then indicates that they were unable to recover after the exceptionally large El Nino event of the 1940s," the scientists wrote. "This may reflect the increasing dominance of anthropogenic forcing since that time but implies that this involved large-scale, in additional to local, atmospheric and ocean circulation changes."
Re: Gee. What was Europe and The West doing? (Score:2)
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> Next time it will have something to do with inventing the wheel? I'm no denier but come on now.
Actually, I suppose that after inventing the wheel we trashed the climate by domesticating horses etc to pull our wheeled contraptions.
We should never have left the trees!
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Re: Gee. What was Europe and The West doing? (Score:1)
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The bikini was also invented in the 1940s. Coincidence?
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1940 has 4 digits in it, the 3rd digit is a 4 and it's followed by a zero. And the first 2 digits add to 10. Add those together and they add to 1; the same as the first digit!
Omg!
Probably only in the distant future (Score:3)
...will climatologists be able to pick apart what was caused by natural events and what was caused by man made global warming. I suspect it will show that the earth was entering a slow warming cycle anyway which would have eventually become a cooling one again, but humans dumping a load of CO2 into the atmosphere and cutting down forest that could re-absorb it upset this cycle and set the climate on a one way trip to a new hotter normal.
Re: Probably only in the distant future (Score:3)
Re: Probably only in the distant future (Score:5, Insightful)
Emissions need to be cut because added ever more CO2 won't do anyone any good (even plants past about 500ppm don't gain from any more). People seem to be under the impression that climate change is headed for a certain equilibrium which it'll then stick at but we have no evidence that'll occur and the only sane approach is too assume things will keep getting warmer so long as we keep adding CO2.
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Ummm.. "even plants past about 500ppm don't gain from any more". No.
As usual, Google is your friend: "The level of 1000 PPM CO2 is very close to the optimum level of CO2 required, given no other limiting factor, 1200 PPM, to allow a plant to photosynthesis at the maximum rate."
Flowering plants can use 1500 PPM - I'd say probably 1800-2000 PPM is the level where plant's don't gain from any more CO2.
Re: Probably only in the distant future (Score:5, Insightful)
>There is no scientific evidence of more catastrophic outcomes.
More heat means a more energetic environment - more violent storms.
More CO2 means dumber people, as high CO2 concentrations impair cognition.
Rapid change - over decades and centuries rather than millennia - causes significant ecosystem damage as species cannot evolve quickly enough to adapt resulting in large die-offs. This will affect us as food chains are disrupted and we find our food sources reduced.
Change also means we can expect climate shifting. Which means people migrating away from areas that no longer support them into those that can. This will inevitably lead to war and all the death and destruction that comes along with it.
As you pointed out yourself, "raising sea levels are of concern due to all those living along the cost". Current estimates are that ~400 million people will be moving in the next 80 years due to that. This is not a small effect.
In short, it is ABSOLUTELY worth it only for the climate.
Re: Probably only in the distant future (Score:5, Interesting)
Rapid change - over decades and centuries rather than millennia - causes significant ecosystem damage as species cannot evolve quickly enough to adapt resulting in large die-offs. This will affect us as food chains are disrupted and we find our food sources reduced.
More energy means more volatility, where I am last year we had roughly normal precipitation but had a serious drought at the same time. Thats because there was no rain for months, then it all came at once in a massive flooding runoff event and the ground did not absorb it well enough to even things out. We have had under normal precipitation but nothing serious during the winter, but there is no snow which is highly abnormal at feet below average and have had record temps with this being the warmest winter on record so far, without the spring run off farming will be impacted and we are sliding even deeper into drought. This will also make wildfires worse which has browned the skies over my state for months and blotted out the sun, with alerts to not breathe outside even in the wilderness away from cities. Hail events and very strong wind events are on the rise as well. So even though the growing season is two weeks longer now than 50 years ago, and even though there is a microscopic amount more CO2 for plants, it’s not clear at all that this will translate into better crops or more food, in fact so far net production is down.
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You are incorrect. It mixes fairly well, though pressure decrease with altitude will cause lower readings and require sensor calibration to correct for the effect.
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"Correct me if I'm wrong,"
You are wrong. I'm guessing you didn't win the science prize at school.
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I'm all for your post in general but CO2 impairing cognition is something that is several orders of magnitude away from being related to climate change. We are talking about 500ppm (more than doubling the atmospheric concentration) leading to something like a 1-2% decline in cognitive ability (on timed tests).
If you have an indoor meeting in a closed room in winter and you're registering 2000ppm, open the window. Otherwise your concerns about atmospheric CO2 are unfounded here. We'll all be dead long before
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Trees are way inferior in regards to absorbing CO2 for two reasons.
1. They are too slow to grow, they barely make a dent.
2. When they die all that CO2 is released again. They are part of the carbon cycle, trees thus have a net balance effect, what they absorb they then release.
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Tell both parties to screw off and build with wood, the lumber interests have an economic interest in planting fas
El Nino since the 1940's? (Score:5, Funny)
He should now be referred to as El Adulto. I am of course speaking as an Ingles linguist, and an armchair scientist.
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Volcanism May Be the Culprit (Score:4, Interesting)
Subglacial volcanism is impacting the flow of the Thwaites Glacier. Subglacial volcanism and other lithospheric processes have increased basal geothermal heat flux and basal melting.https://www.science.org/doi/10.1126/sciadv.adf2639
You mean ... (Score:1)
... it's NOT due to sin???
Heretic!
Why wouldn't it start this early? (Score:4, Insightful)
Climate change didn't start when we were able to detect it, it started when we started changing the atmospheric composition by pumping CO2 into it. It accelerated post-1940s for sure, but it will have begun before then. So why wouldn't the actual warming have begun before we detected it? After all, we didn't even think to start looking until later. While this glacier may have started melting due to other factors than CO2 emissions, the fact that it started in the 40s doesn't prove this case.
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It started when we discovered fire basically, just the climate change from that was slow and slight so we thought it was natural.
We should never have discovered fire.
Re:Why wouldn't it start this early? (Score:5, Insightful)
This is emblematic of the problem with intelligent discussion of scientific matters in the public forum: allowing the dissemination of information potentially contrary to one's premise becomes a tempting target for obfuscation.
Science should always stay on the side of truth-telling and embracing new information, especially when the information appears contrarian.
A single instance of stating "Masks won't help the public," helped destroyed the high ground scientists and virologists worked so hard to hold.
Re:Why wouldn't it start this early? (Score:4, Interesting)
This is emblematic of the problem with intelligent discussion of scientific matters in the public forum: allowing the dissemination of information potentially contrary to one's premise becomes a tempting target for obfuscation.
Science should always stay on the side of truth-telling and embracing new information, especially when the information appears contrarian.
Depends entirely on what you mean by "embracing." If you consider taking in new information and analyzing it, researching it, studying it, or even doing experiments to verify it "embracing," I would agree with you. But if you consider "embracing" to mean "accepting outright," then we're going to be at an impasse.
A single instance of stating "Masks won't help the public," helped destroyed the high ground scientists and virologists worked so hard to hold.
As I said above. If you "embrace" new information by simply accepting it, you end up with exactly the situation we landed in. Skepticism still has a place in science, it just shouldn't be used to outright reject every contrary position. Verification of some means or another is vital.
This is why single studies and data are always at least somewhat suspect until verified by a reliable third-party, or several reliable third-parties.
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There's a chasm of difference, as you clearly understand, between embracing the introduction of new and potentially contrarian information, and accepting it as likely factual.
All we know for sure, is that some of the things we presently believe are factually incorrect. All of us. Every one.
Somehow, and this is the stretch, we need almost desperately to convey this identical sentiment to our fearless leaders. That single ideal might open the tried and true ideal of reaching across the aisle to listen to an
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Climate change didn't start when we were able to detect it, it started when we started changing the atmospheric composition by pumping CO2 into it.
Climate change is continual. AGW began when we first started burning down forests for agriculture and the melting of glaciers accelerated during the industrial revolution when our soot began landing on them, even before we had made any substantial contribution to atmospheric CO2.
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Re:im curious (Score:5, Interesting)
...Hill notes that it's often referred to as the "doomsday glacier" due to the potentially catastrophic consequences of its hypothetical collapse.
whats gona happen exactly?
If the estimates are correct, sea levels worldwide would rise anywhere from two feet to eight feet [mashable.com]. Which doesn't sound like a lot until you take into consideration how low some cities are above sea level, such as Miami, low lying places in Mississippi and Alabama, and combine that with the increased coastal erosion.
In addition, the increase in sea levels could cause an increase in the melting of other glaciers which would further raise sea levels, potentially, by another ten feet [space.com]. That's when the fun begins.
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Re: im curious (Score:1)
Maybe it's as 'Doomsday' a glacier can get....
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whats gona happen exactly?
Doomsday!
Can you not read?
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Well, not too much initially, though still not good. A little over a half-metre of sea level rise (which used to be hundreds of years off but newer estimates make it just barely possible some of us discussing it right now will live to see it with some of the more extreme worst-case estimates being 'within 5 years').
But Thwaites is a wall holding back a much bigger mass of ice that is currently above sea level. With Thwaites gone, that additional ice will begin sliding into the ocean and ultimately bring a
They are not supposed to recover (Score:3, Insightful)
They were created when the earth froze.
Thus they were always going to melt.
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'Supposed to'. That implies some kind of plan and intent.
In reality, these ice shelves melted and recovered all the time - the world isn't 'supposed to' be warm enough for them to permanently melt just yet. The 'supposed to' timeline is much, much longer than the changes we're seeing in our lifetimes.
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They were created when the earth froze.
Thus they were always going to melt.
Well, that is the interesting thing about Reality: Some things are guaranteed to happen, but the question of WHEN becomes a real question. You jump out of an airplane: You are absolutely guaranteed to hit the ground. You should die right? Well, if you open a parachute to slow your descent, you may not die.
Same thing here except that instead of opening a parachute, we are creating an aerodynamic wedge.
You may have been aquitted... (Score:2)
But you're still guilty.
Long term coastal instability (Score:2)
Question (Score:2)
Please be gentle; I'm asking in ignorance.
If Thwaites lost contact with the sea floor a half-century ago, does that mean it's no longer supported by a land mass? I.e. Has the corresponding sea level rise has already occurred?
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Please be gentle; I'm asking in ignorance.
If Thwaites lost contact with the sea floor a half-century ago, does that mean it's no longer supported by a land mass? I.e. Has the corresponding sea level rise has already occurred?
This is the question I was scrolling through to find, because the article summary says "they found the Thwaites and Pine Island glaciers both lost contact with the seafloor highs in the 1940s." However it turns out that's only part of the abstract, and the actual article shows that there are non-floating portions, and "Thwaites Glacier’s floating margin is composed of the Eastern Ice Shelf, which remains pinned to (resting on) a seafloor high, and the Thwaites Glacier Tongue, which lost contact with t
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When the ice shelf breaks free (Score:2)
Maybe that would convince them that human based climate change is real. Maybe not. Either way they would no longer be around to keep fucking things up. Bonus p
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I think it would be more fair to put them somewhere that used to be survivable but has gotten a bit hotter in the last 100 years, and let them go via hyperthermia.
Putting them somewhere that's just not as cold as it should be doesn't really drive home the lesson.
Thwaites? (Score:2)
Good one (Score:2)