|
| deafpolygon wrote:
| Isn't this the basically the plot to the prequel of The Thing?
| taf2 wrote:
| From the picture that looks like a pretty large hole... any
| chance that execrates the melting process by increasing the
| surface area? Or is it insignificant just curious if someone has
| thought about or done any calculations...
| sgirard wrote:
| Interesting: "Towards the base, the ice is more than 120,000
| years old and dates back to the last interglacial period, a time
| when the atmospheric temperature above Greenland was 5degC warmer
| than today."
| [deleted]
| thomasahle wrote:
| See also this timeline of the last four inter-glacial periods:
| https://co2coalition.org/wp-content/uploads/2021/09/104-4000...
|
| It also shows how crazy it would be if we get the projected 2-3
| degrees average temperature increase. Even in a period where
| we'd expect to be going into a new ice age; instead shooting to
| a previously unseen high temperature.
| slashdev wrote:
| On the other hand if we only have 2-3 degrees of warming, if
| that's enough to prevent the next ice age, didn't we just
| dodge a massive icy bullet? Might we not one day thank
| ourselves for doing something reckless and stupid that
| actually worked out?
|
| Yeah a warmer climate brings all kinds of horrible changes.
| But food still grows in the northern hemisphere. A colder
| climate is arguably even worse for us.
|
| By the way, that's no excuse to keep doing what we're doing.
| Limiting warning at 2-3 degrees will be nice. Things get
| really horrific above 4. At some unknown point feedback
| cycles really kick in and we go to 5-10 degrees and get
| completely fucked. We really have to not find out where that
| threshold is.
| kuprel wrote:
| I didn't realize that the vast majority of the time Earth
| is in an ice age. What causes it periodically like this?
| slashdev wrote:
| It's mostly caused by Milankovitch cycles. Which are
| cyclic variations in our orbit around the sun.
|
| The earth varies in distance to the sun and axial tilt
| and precession. Like waves, there factors can either
| overlap and somewhat cancel or they can stack for a
| larger effect.
| autokad wrote:
| ice ages didn't happen until after the asteroid strike.
| Antarctica moving into the south pole is likely a large
| part of it, but they don't really understand ice ages
| that well TBO. Anyhoo, the Earth was a lot warmer prior
| to the strike and we have been going through extinction
| events every 100k years.
| mkl wrote:
| By "the" asteroid strike I'm guessing you mean the one
| 66M years ago? There were definitely ice ages before
| that, likely including one or more Snowball Earth phases
| (the whole surface frozen):
| https://en.wikipedia.org/wiki/Snowball_Earth.
| monero-xmr wrote:
| [flagged]
| barbazoo wrote:
| Please correct me if I'm wrong. The amplitudes of co2 ppm
| seem to always have been within a certain band though,
| topping out at 300ppm. Right now, we're at 420ppm and
| increasing what looks like exponentially. [0]
|
| I'm not saying humans won't be fine but we've never been so
| dependent on the stability of the climate before. People will
| die, get displaced, suffer economically, etc as far as I
| understand.
|
| [0] https://www.climate.gov/news-features/understanding-
| climate/...
| foota wrote:
| I don't think 800,000 years is that long on the geological
| time scale. (Not that I don't think global warming is a big
| deal etc etc)
| barbazoo wrote:
| It's not but it's also not much less time than what we
| consider "humans" to have been around and we're talking
| about co2 in the atmosphere in the context of whether
| humans will be fine or not.
|
| Of course, for earth it doesn't matter at all.
| px43 wrote:
| It was over 4000ppm during the Cambrian period 500m years
| ago, then down to about where it is today in the
| Carboniferious period, during the 60 million year period
| where trees evolved to make wood, but nothing had evolved
| to eat it yet, so dead trees literally just piled up for 60
| million years. Then during the Mezozoic it went up into the
| 2000s again, lots of dino farts or something? Then back
| under 1000 again and dropping until the last 100 years or
| so.
|
| https://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_a
| t...
|
| Of course, there were also mass migrations and extinctions
| as the environment changed so radically, which seems like
| something that would be nice to avoid.
| barbazoo wrote:
| I was just responding to parent who said
|
| > On the positive, the earth has been much warmer and
| much colder, and has had more carbon and less carbon in
| the atmosphere.
|
| the way I read it suggesting that it'll be fine. But it
| won't be, if co2 increased to 4000 ppm quickly enough,
| humans would not be fine. There were no humans during the
| time you were describing.
| petemir wrote:
| Part of the problem, which you fail to address, is the time
| frame when these changes take place and the possibility of
| the ecosystem to adapt. Yes, we've been much cooler and much
| warmer, with these changes taking place over thousand of
| years: not a couple of centuries.
| [deleted]
| nextaccountic wrote:
| Quick changes in climate generally lead to extinction events.
| And indeed we are in the middle of one. And it's caused by us
|
| https://en.wikipedia.org/wiki/Holocene_extinction
|
| Life will go on. Humans? Maybe. Human civilization will be
| disrupted for sure
|
| Also: here's a visualization of how fast the climate changed
| in the last 20000 years vs today
|
| https://xkcd.com/1732/
|
| The short term effects are all about the slope. And the short
| term is all that matter to us, because if we don't pass
| through this bottleneck we won't have a long term (it may
| well be our "great filter" preventing us from spreading
| through the stars)
| sleet_spotter wrote:
| A critical piece is the speed at which the climate is
| warming. The Earth has had much warmer and colder periods in
| its history that (most) life adapted to. However, life was
| only able to adapt happened because those changes happened at
| a sufficiently slow pace. To perhaps put the current trend in
| the context of geologic time, there have been 5 mass
| extinctions in the fossil record of life on Earth. These are
| associated with rapid changes in climate (e.g. asteroid
| impacts, large volcanic eruptions). Anthropogenic climate
| change is driving Earth's 6th mass extinction event. To be
| clear: what is happening now has not happened often in
| Earth's history. Life has survived, but it has not been
| pretty. Some alarmism is warranted from the ecosystem
| collapse alone.
|
| https://en.wikipedia.org/wiki/Extinction_event
| https://en.wikipedia.org/wiki/Holocene_extinction
| btilly wrote:
| More at issue is that rates of change matter.
|
| When temperature rises slowly, ecosystems adapt in parallel
| to the change. When temperature rises fast, ecosystems don't.
| And so we have major die-offs of coral and trees, without
| corresponding colonization in places where they could now
| live.
|
| When CO2 rises slowly, the ocean's pH is buffered by large
| deposits of calcium carbonate on the bottom. When CO2 rises
| fast, we get ocean acidification, which is on track to be the
| most extreme shellfish extinction event in the last 50
| million years.
|
| Therefore larger absolute past climate changes were less
| likely to have extreme impacts than faster present climate
| changes.
| alberth wrote:
| > _" On the positive, the earth has been much warmer and much
| colder"_
|
| The concern is, during these hotter/colder periods of earth's
| existence - what happened to life on earth during that time?
|
| Did populations decline? Was life nearly run into extinction
| (dinosaurs, etc)?
| bparsons wrote:
| My whole country being on fire since May has been pretty
| apocalyptic.
| spockz wrote:
| Although indeed the temperatures and GHG have been lower and
| higher on Earth before, that was never with the amount of
| humans we have now. Our economy and society is quite
| optimised and our infrastructure hubs are largely located on
| coasts. Our prosperity also relies on a large amount of
| sophisticated technology that is hard to replace and to
| bootstrap.
|
| So although the human species will probably survive a drastic
| climate change, many individuals will not due to famine, lack
| of medical supplies and care, and war over the remaining
| resources.
| hnhg wrote:
| It is also because it will result in incredible levels of
| migration and competition for resources in the short term (ie
| wars). Yes, humanity will survive but it might make global
| shocks like the pandemic seem very tepid by comparison.
| shostack wrote:
| The earth may have survived those changes, but not all its
| inhabitants may have. So there definitely is still reason to
| worry as far as humanity is concerned.
|
| The major ecological shifts may bring change humanity does
| not bounce back from.
| notfish wrote:
| When the cause for optimism is "some humans will probably
| survive", I don't feel very optimistic
| FrustratedMonky wrote:
| >>"The doomsday cult saying we are all going to die, or that
| every single heat wave and natural disaster can be pinned on
| extra carbon, are just yet another in a long line of
| apocalyptic predictors"
|
| The problem with this argument is that 'humans' surviving, is
| different than 'our nice comfortable human society'
| surviving.
|
| Yes, the human species as an animal that can survive by
| foraging, probably will survive. That isn't a great argument.
| dakial1 wrote:
| Not all natural disasters can be pinned into global warming
| (earthquakes for example), also some weather related
| disasters are caused by cyclical patterns (e.g. El Nino), but
| certainly the higher frequency (and potency) of some weather
| related disasters are already linked to human influence:
| https://news.un.org/en/story/2021/09/1098662
|
| Is not doomsday as the world won't change overnight, but some
| areas of the globe will suffer a lot from the higher
| intensity of the weather and this will probably create a lot
| of global challenges and might bring (mostly) overcome
| tragedies, like widespread famine, back to the news
| mariuolo wrote:
| It's true the Earth has been much warmer and much colder, but
| it's also true we haven't always been there.
| anigbrowl wrote:
| _The doomsday cult_
|
| Oh shut it. You can't have any knowledge at all about this
| issue and not appreciate that the problem is not temperature
| as such but the rapidity of the change - over 150 years
| rather than 15000. Your troll post is an insult to
| intelligence.
|
| Folks, don't waste your time trying to reason with such bad-
| faith arguments. It's a form of theft, because the time cost
| to refute bullshit is about 10x that to spew bullshit. And
| the above post is just that - bullshit.
|
| Before someone invokes the HN guidelines and talks about
| curious conversation, recognize that throwing phrases like
| 'doomsday cult' into a discussion of a serious scientific
| project that has hit a milestone after many years of effort
| has only one purpose, and that is to derail. Flagging and
| downvoting are all very well, but there are also times when
| it's necessary to call bullshit.
| briantakita wrote:
| You seem angry, so I'm going to try to explain (from my
| perspective) why someone may have the perception that you
| reacted to.
|
| There is plenty of criticism over relying on mathematical
| models that fail to accurately predict the future (all of
| the glaciers were predicted to have melted 3 years ago,
| snow was supposed to have been a thing of the past, etc.),
| cherry picking data, questionable measurement & sampling,
| not considering other forcing inputs, etc. It's a
| complicated claim that has valid criticism on it's
| foundational pieces If any foundational premise of the
| claim is invalidated, the entire model is invalidated. The
| consensus models are complicated so I'm not surprised that
| it has a difficult time standing up against scrutiny &
| needs to be adjusted frequently.
|
| There is also dissent among scientists, including from
| Nobel Laureates (who had opportunities cancelled after
| dissenting). "The doomsday cult" reference comes from the
| doom & gloom sensationalism. For example, I a heard chorus
| of "we are fucked" from coworkers in the office about 15
| years ago in response to some news back then. I don't agree
| that "we are fucked". Humans have been through more
| environmentally challenging times with less technology &
| global knowledge.
|
| The climate is changing...always has changed & always will
| change. What are we going to do about it? Are we going to
| pretend that we can stave off the inevitable,
| taxing/restricting the population which weakens their
| ability to adjust to these inevitable changes...while
| wealth is concentrated to the elites? There is a widespread
| perception that is happening. When the issues reach it's
| crescendo later in this decade & the fallout in the 2030s
| (winter occurs after the Solar Solstice, solar exposure
| increases during winter), there will be many who will not
| buy the APGW narrative as the reason for their problems.
| The peaceful solution is a decoupling from systems that
| don't benefit the person/group, which I expect to happen.
| Others, such as Peter Turchin think there is a high
| probability of violent uprising & he seems to think
| addressing APGW is a unifying force...I disagree on both
| premises but I think his analysis is valid & worth getting
| into.
|
| I think the animus generated by climate alarmism putting
| the blame on the population reduces effective cooperation
| among people & will be exasperated as the climate does
| change, as the Geomagnetic wander deepens in it's cycle, as
| magnetic fields fluctuate in our solar system, etc. A
| spirit of cooperation will unify humanity while the blame
| game will cause conflict. Doom & gloom is unhelpful. The
| "doomsday cult" will increase in their doom & gloom as
| people walk away from their petulance & their social
| leverage wanes.
| arp242 wrote:
| > all of the glaciers were predicted to have melted 3
| years ago
|
| I don't think any mainstream models predicted that? Which
| model was that?
|
| Also remember that our actions are influenced by models.
| "If current trends persist, then in 20 years [...]" may
| very well be true, but if we take action based on those
| predictions (e.g. change the trend) then the outcome will
| be different.
|
| You can see this clearly in population levels of things
| like elephants[1] or whales[2]: people who were
| predicting the extinction of whales and elephants weren't
| wrong.
|
| [1]: https://ourworldindata.org/grapher/african-elephants
|
| [2]: https://www.researchgate.net/figure/General-
| estimated-popula...
| toss1 wrote:
| Yes, there have been warm and cold intervals in the past.
|
| NONE of them happened at anything approaching the _RATE_ of
| today 's anthropogenic warming.
|
| Our climate is warming literally orders of magnitude faster
| than any previous change. This is overwhelming the ability of
| ecosystems to adapt.
|
| Moreover, this is entirely preventable -- we're doing it, we
| can stop it.
| snowwrestler wrote:
| People worry about accelerating climate change now because we
| live here now.
|
| It's not a theoretical science thing. We have farms and
| cities and towns and bridges and dams and reservoirs in
| particular places, and we are accelerating the depreciation
| of many of them. The result will be tremendous loss of
| wealth, movement of populations, and the associated social
| consequences of those.
|
| Humanity doesn't hate itself, we like ourselves, which is why
| we are so concerned about what we are doing to ourselves.
| viscanti wrote:
| > Humanity doesn't hate itself, we like ourselves, which is
| why we are so concerned about what we are doing to
| ourselves.
|
| Yeah. The argument that single cellular life or some small
| animals might survive and eventually evolve into something
| else is a bit weird for people who are hoping they don't
| die out like many species have in the past when there have
| been major changes to climate and carbon levels.
| warning26 wrote:
| Exactly. People often get lost in this "we must save the
| planet" argument, but realistically, the planet is gonna
| be fine.
|
| Preventing climate change is about saving _humanity_ ,
| not the planet.
| etrautmann wrote:
| How is this pedantic point useful in any way?
| mikestew wrote:
| I swear, if _one_ more person quotes an old George Carlin
| bit, as if it were still clever or useful...or as if said
| person didn 't know what was meant by the statement.
| xp84 wrote:
| > How is this pedantic point useful in any way?
|
| Because it forces us to recognize that the risk isn't to
| "the Earth" as a separate entity, but to ourselves
| specifically (well, our future descendants).
|
| We've already confirmed through our behavior that humans
| largely don't care about any other part of the Earth
| ecosystem, so asking people to basically do the right
| thing as a favor to the Earth are probably wasting their
| time.
| toshk wrote:
| Yeah but there is more to it. There are active crisis, like
| cancer & heart disease. Or upcoming ones like Alzeimer &
| Parkinson. That in the current day already affect more
| people per year, then the climate crisis will affect in the
| worst prognoses in a 100 years*.
|
| But Climate change is different, it speaks to the psyche of
| humans, the modern story of the flood. And in the same way
| it gives people meaning & without religion in the West they
| form morality around it. Those for it, are good, those
| against it, are bad.
|
| That doesn't mean its not something important or real, and
| we have to solve it. But it's one of the many things for us
| humans to solve.
|
| *In worst prognoses, climate changes will affect 10 mil
| deaths per year, which is the same amount cancer is doing
| every year today.
| cycomanic wrote:
| Except that neither of the things you mention affects
| more people than climate change will. The estimate is
| that there are about 54 M people World wide suffering
| from alzheimer.
|
| The worst case projection for 2100 for just sea rise is
| 4-5m on global average (but much higher in some areas) ht
| tps://iopscience.iop.org/article/10.1088/1748-9326/acb504
|
| To put that into perspective the average altitude of
| Bangladesh is 9m above sea level, but the majority of the
| population lives in he south at about 0-1m of altitude.
| So there would just in Bangladesh alone be more people
| (let's say 50% of 160M) directly affected by climate
| change than alzheimer world wide. We are not even talking
| about the indirect effects of displacing 60M people, all
| the other countries and all the other effects of climate
| change.
|
| Apart from that, the argument is under the false premise
| that we shouldnt do anything anyway because there is
| worse things. By that argument we should also not do
| something about alzheimer, because more people die of
| cancer.
|
| So I question what your aim was with your argument. It
| was clearly using wrong facts and was under a false
| premise.
| toshk wrote:
| Just because they will below sea level doesn't mean they
| will all die. That's a bit ludicrous. Even more ludicrous
| are your nrs 4-5 meters, will get to that.
|
| Whole of Holland is below sea level at the moment. Yet we
| are miraculously sitil alive.
|
| To take it further, in a 100 years every house in Holland
| that's here now will still be standing.
|
| Now certain countries don't have the skills that the
| Dutch have, and we should help them. But this isn't
| something that will come unexpected, so we have the time
| to do so. Half of Dubai was created out of the sea.
|
| But, even then 4-5 meters is too much. Worst case is less
| then 1m. Till now we got 20cm. Expectance by Dutch gov.
| is this between another 20 and 86 cm in the next century:
| https://www.knmi.nl/kennis-en-
| datacentrum/uitleg/zeespiegels...
|
| Back to the medical argument. Even if parts are flooded,
| which is terrible. Moving away is not the same as not
| being able to use your brain or dying.
| downWidOutaFite wrote:
| If you're in the "head in the sand cult" you might be
| obliviously happier than the the "doomsday cult", but our
| ancestors will hate you much more.
| mytailorisrich wrote:
| Iirc, the CO2 concentration now as been pumped up higher than
| it was then, which is in part what is worrying because temps
| might then potentially shoot even higher.
|
| Bottom line: we need large scale carbon capture quickly because
| even if we reach net zero CO2 will take millenia to drop back
| to the level it was pre-industrial revolution.
|
| Edit: I wouldn't focus on "pre-industrial levels" specifically,
| the point is that there is too much now so we most likely want
| concentration to drop as soon as possible.
| lehi wrote:
| The Keeling Curve is eye-opening for understanding our
| current versus (pre-)historical CO2 levels:
| https://tywkiwdbi.blogspot.com/2023/07/introducing-
| keeling-c...
| BurningFrog wrote:
| > _Bottom line: we need large scale carbon capture quickly_
|
| The short term solution/bandaid is pumping SO2 into the
| stratosphere while we figure out carbon capture.
| XorNot wrote:
| I do wonder if some of the "massed solar sail" ideas for
| terraforming Mars' atmosphere would work here (in short:
| use cellphone processors to build and launch a couple
| hundred thousand solar-sail equipped satellites).
|
| Because it would be expensive, but it would kill several
| birds with one stone: we (1) prove whether the concept
| would work on Mars, (2) develop the technology to do it,
| and (3) unlike SO2 in the atmosphere, "switching it off" or
| modifying the scale of the effect can be done almost
| instantly (you could remove the swarm by having it fall
| back to an Earth orbit).
| elzbardico wrote:
| Why do we need to get back to the levels pre-industrial
| revolution?
| angiosperm wrote:
| We have also pumped a very large amount of long-lived
| fluorine compounds into the air, that will last for
| centuries. They have from 2500x to 25000x times the
| "greenhouse gas warming potential", kg for kg. They are
| mostly refrigerants (CFCs, HFCs, and soon their successors)
| and transformer insulation gas (SF6). Volcanoes do emit
| some amount of fluorine compounds, too.
|
| We also have a great deal of methane leakage, which is
| usually cited as 25-100x, and we may soon have a lot of
| hydrogen leakage, at >100x. Rocket launches are installing
| water vapor, another one, into the stratosphere like never
| before.
|
| So even if we got CO2 down to a pre-industrial level, we
| would still have heat forcing from the fluorine- and other
| compounds.
|
| Capturing CO2 is kind of pointless until we get emissions
| under control. I.e., a dollar spent preventing emissions
| buys much more than a dollar spent capturing. Solar panels
| and wind turbines directly displace mass emitters of CO2.
| specialist wrote:
| Yes and: I understand that we want to prevent the non-
| human emissions from becoming a positive feedback loop.
| Meaning that at some tipping point, the thawing tundra,
| burning forests, and acidic oceans will continue to get
| worse, even if/when human emissions completely stop.
| mytailorisrich wrote:
| I don't know about all compounds but CFCs stay in
| atmosphere for about a century only and we've already
| banned them, and methane has a very short lifetime of
| about 12 years. So we 'only' need to control emissions of
| those to solve the problem.
|
| On the other hand, as said, CO2 stays for centuries if
| not 1,000+ years so at this point net zero is only half
| the job though probably the hardest part.
| zdragnar wrote:
| Methane, at least, breaks down to CO2, no?
| e_i_pi_2 wrote:
| That is the point where we started adding greenhouse gases
| that lock in energy from the sun, we need to at least get
| back to those levels to start releasing some of the heat.
| Otherwise we're containing to add insulation to an oven
| that already overheating - you'd ideally want to take off
| all the insulation and the metal casing since you can't
| turn off the heat, but the casing isn't an option so we
| need to remove the insulation and hope it hasn't gotten too
| bad yet
| mytailorisrich wrote:
| The point is that net zero is most likely not going to stop
| warming with 400+ppm CO2 in the atmosphere. CO2
| concentration most likely has to drop but naturally it does
| so very slowly. Arguably at this point we already need
| _cooling_ because 40+C every summer in half of Europe (for
| instance) is getting annoying...
| gottorf wrote:
| > at this point we already need cooling
|
| A colossal volcanic eruption could do the trick, and
| those seem to happen rather unnervingly frequently.
| sleet_spotter wrote:
| Pre-industrial CO2 concentration is synonymous with the
| "natural concentration", at least in the recent past. We
| made a very large change that has thrown Earth's systems
| out of equilibrium. Returning to pre-industrial CO2 levels
| would undo that change and bring things back towards
| equilibrium.
| thrashh wrote:
| Like the other reply said, there is no natural
| equilibrium.
|
| We want to return to pre-industrial levels because we're
| used to it and we liked it more then.
| tenpies wrote:
| I like to think of it as scrappy terraforming because we
| aren't even sure we could handle any of the naturally
| occurring variation.
|
| Scrappy because, well the planet doesn't quite become
| uninhabitable and we're starting from the end-game.
| Science fiction also had me expecting some very cool
| terraforming infrastructure, not psy-ops to get the serfs
| to eat bugs.
| thrawa8387336 wrote:
| Really
| nonethewiser wrote:
| "Natural concentration" is not the right way to look at
| it because there are higher concentrations that predate
| the industrial revolution and humans. The all time high
| (that we know of) is from about 350,000 years ago. This
| was by all means natural and pre industrial revolution.
| adhesive_wombat wrote:
| "The only known natural concentration empirically
| compatible with long-term human civilisation".
|
| "The planet did exist/will exist just fine without us" is
| a pretty worn truism. You might as well wryly note that
| water isn't natural because everything was hydrogen once.
| gottorf wrote:
| > empirically compatible with long-term human
| civilisation
|
| Empirically observed, atmospheric CO2 went from ~320ppm
| to ~410ppm from 1970 to 2020[0], during which period the
| human population more than doubled from ~3.7B to ~7.8B
| and yet deaths caused by climate dropped threefold[1]
| (not 1/3 the rate; 1/3 in absolute number).
|
| [0]: https://www.climate.gov/news-features/understanding-
| climate/...
|
| [1]: https://library.wmo.int/doc_num.php?explnum_id=10989
| adhesive_wombat wrote:
| On the scale of human civilisation, 50 years is hardly
| "long term".
|
| Polonium by that ultra-short-relative-term reckoning is
| not only harmless as it you still feel fine 10 minutes
| later, but actually healthsome as you rather feel
| refreshed by the delicious green tea you just drank in
| that 5-star hotel bar.
| colechristensen wrote:
| They are dynamical systems, there is no equilibrium. See
| also: climate charts for the last few ice age cycles.[1]
| In the bigger picture we _want_ to modify Earth 's
| climate and definitely do not want to end the current
| interglacial period, to be fair we've already done that,
| but returning to a "natural" pre-human climate cycle on
| the 10,000 year scale is not desirable.
|
| 1.
| https://energyeducation.ca/wiki/images/8/8f/Ice_ages2.gif
| pinkmuffinere wrote:
| Dynamical systems can have equilibrium points --- e.g. an
| inverted pendulum is stable when hanging straight down.
| If you deviate too far from an equilibrium point, the
| system may find another equilibrium that is less
| desirable for the user. I'm not an expert in climate
| change, but those things certainly happen for engines,
| robots, and other systems.
| adolph wrote:
| 120k years ago in context: * 170,000 years ago:
| humans are wearing clothing by this date. * 125,000 years
| ago: the peak of the Eemian interglacial period. *
| ~120,000 years ago: possibly the earliest evidence of use of
| symbols etched onto bone * 75,000 years ago: Toba Volcano
| supereruption that may have contributed to human populations
| being lowered to about 15,000 people
|
| https://en.wikipedia.org/wiki/Timeline_of_prehistory
|
| _The Eemian climate is believed to have been warmer than the
| current Holocene. Changes in the Earth 's orbital parameters
| from today (greater obliquity and eccentricity, and
| perihelion), known as Milankovitch cycles, probably led to
| greater seasonal temperature variations in the Northern
| Hemisphere. During the northern summer, temperatures in the
| Arctic region were about 2-4 degC higher than in 2011._
|
| _The hippopotamus was distributed as far north as the rivers
| Rhine and Thames. . . . The prairie-forest boundary in the
| Great Plains of the United States lay further west near
| Lubbock, Texas, whereas the current boundary is near Dallas. .
| . . Sea level at peak was probably 6 to 9 metres (20 to 30
| feet) higher than today . . . ._
|
| https://en.wikipedia.org/wiki/Eemian
| orangepurple wrote:
| This raises a very critical point. Nuclear is the only
| dependable energy source. Fossil fuels will run out or go out
| of favor. Solar and wind on the other hand will become
| victims of the next major volcanic eruption as ash destroys
| them or renders them ineffective.
| dredmorbius wrote:
| An eruption significant enough to impact solar and wind
| generation globally will also affect _other_ critical
| requirements of humanity, and the Earth 's ecosystem,
| globally.
|
| Which is to say: You Will Be Having Bigger Problems.
|
| Recovery from regional meterological catastrophes is well
| within human capabilities.
| ricardobeat wrote:
| Nuclear facilities seem pretty fragile / demanding, I doubt
| one would survive any kind of apocalyptic event. The
| infrastructure supporting it will be gone.
| fullstackchris wrote:
| isnt that the case with any advanced technology?
| (including wind and solar)
| XorNot wrote:
| Deep drilling based geothermal can fill this role too
| though - and does have the substantial benefit over nuclear
| that it leaves no surface-supply chains for resources
| (uranium).
|
| Given that we're so close to being able to do it, we
| honestly need a Manhattan project initiative to push it
| through to reality (with the outcome being the machine and
| process to do the drilling).
| angiosperm wrote:
| There is definite evidence of hominins in North America
| 130,000 years ago (search "Cerutti mastodon"). Nobody knows
| if they were _H. erectus_ , Neanderthal, Denisovan, modern
| humans, or "other", but with an interglacial at 125,000 years
| ago, it is not hard to see how they could have got here.
| biztos wrote:
| Wikipedia suggests this is not definitive, and maybe not
| even evidence:
|
| https://en.wikipedia.org/wiki/Cerutti_Mastodon_site#Critici
| s...
|
| This article is much more sympathetic (and also a fun
| read):
|
| https://www.latimes.com/local/california/la-me-cerutti-
| masto...
|
| I'm no expert but it seems like this is still a
| controversial idea.
| wheelerof4te wrote:
| "75,000 years ago: Toba Volcano supereruption that may have
| contributed to human populations being lowered to about
| 15,000 people."
|
| The key question is: How much CO2 did that super-eruption
| emit into the atmosphere?
|
| In our hurry to attribute climate change to our meager impact
| on this planet, we tend to forget what horrors an eruption of
| this magnitude can cause. And who knows how many of them
| happened during the past millennia.
| pmayrgundter wrote:
| The figure I've found is 2800 km^3 of approximately
| granite, which at 2.7 tonnes per cubic meter gives about a
| billion gigatons ejecta.
|
| I've never found a CO2 estimate, but did find that it's a
| significant amount of that mass, as is SO2.
|
| It wasn't worth me doing more of a sketch since it's not
| clear how to model the effects of such a massive system.
|
| I was struck tho, that the magnitude of this and a few
| other events in the not too distant past, are vastly larger
| than even all put nuclear war
|
| It's not clear to me that our CO2 emissions are very
| significant in comparison
| dredmorbius wrote:
| Wikipedia cites a range of 2,000 -- 13,000 km^3.
|
|
|
| I'm _not_ finding a good source on overall composition of
| volcanic eruptions, either generally or by type. Anyone
| else?
|
| One of the largest volcanic events I'm aware of is the
| Siberian Traps eruption, about 250 mya, with a volume of
| about 4 million km^3, another three orders of magnitude
| greater than Tomba.
|
| This has been linked to the Permian-Triassic mass
| extinction event, with the mechanism being release of
| methane clathrates and/or stimulating growth of a microbe
| which released vast quantities of methane into the
| atmosphere, killing ~81% of all extant marine species and
| 70% of terrestrial vertebrate species.
|
|
|
| "The level of atmospheric carbon dioxide rose from around
| 400 ppm to 2,500 ppm with approximately 3,900 to 12,000
| gigatonnes of carbon being added to the ocean-atmosphere
| system during this period."
|
| -- Wikipedia, citing Wu, Yuyang; Chu, Daoliang; Tong,
| Jinnan; Song, Haijun; Dal Corso, Jacopo; Wignall, Paul
| B.; Song, Huyue; Du, Yong; Cui, Ying (9 April 2021).
| "Six-fold increase of atmospheric pCO2 during the
| Permian-Triassic mass extinction". Nature Communications.
| 12 (1): 2137. Bibcode:2021NatCo..12.2137W.
| doi:10.1038/s41467-021-22298-7.
|
|
| mschuster91 wrote:
| > And who knows how many of them happened during the past
| millennia.
|
| We at least have a significantly large list of what we know
| [1] - that's part of the purpose of core drilling, the ash
| deposits worldwide can be linked together to estimate where
| ash traveled to. Also, craters and their surrounding can be
| drilled into to determine eruption events.
|
| [1] https://en.wikipedia.org/wiki/List_of_large_volcanic_er
| uptio...
| pmayrgundter wrote:
| Here's a study:
|
| The size and frequency of the largest explosive eruptions
| on Earth, Mason 2004
|
| https://www.researchgate.net/publication/227000709_The_si
| ze_...
| FireBeyond wrote:
| I think people struggle with the magnitude.
|
| Mt St Helens, for example. Not the largest eruption.
|
| But a landslide of approximately 2.5km^3 (over 3 billion
| cubic yards).
|
| Okay, some say, so that is a lot of earth...
|
| and then you learn that the landslide was moving at speeds
| of up to 160mph.
|
| That's a LOT of energy.
| staunton wrote:
| Volcanoes aren't about the CO2, they're about the ash which
| blocks out the sun and makes it colder.
| newfonewhodis wrote:
| I'm not a scientist so I'm curious why this is interesting.
| p1esk wrote:
| Presumably because we can find well preserved organisms from
| that time.
| snowwrestler wrote:
| I think people who are not already familiar with the known
| history of the Earth find it interesting that there have been
| higher CO2 levels and temps than there are now.
|
| And I agree: the history of the Earth _is_ interesting. Which
| is why so many people study and work in the field of geology.
| sgirard wrote:
| I find it interesting because it raises questions that I
| don't have answers to. For example:
|
| - What caused the temperature above Greenland to be 5degC
| warmer than today? Why is it cooler now compared to 120,000
| years ago? What causes the interglacial periods? Is
| glaciation the more common state of the climate?
|
| - The article says the ice sheet is melting at the bottom?
| Why? Pressure from above? Friction from movement? Heat from
| the Earth? Something else?
|
| - Was the ice sheet shrinking or growing when the
| temperatures above Greenland were 5degC warmer than now? Does
| existence of the ice sheet imply that 5degC warmer for some
| period of time is not enough to melt the Greenland ice sheet?
|
| - How much climate data has been lost to melting from the
| bottom? Is the ice sheet thickening or thinning compared
| 120,000 years ago? How would we know?
|
| - How much has the Greenland land mass moved in 120,000 years
| due to plate tectonics? Could this have impacted the ice
| sheet in this short amount of time?
|
| - Humans adapt. How did humans adapt to a climate that was
| warmer by up to 5degC 120,000 years ago?
|
| - How long did the warm temperatures persist 120,000 years
| ago? 10,000 years? 50,000 years? Or more?
|
| - Could a cooling climate be more worrisome to humanity than
| a warming one?
| detourdog wrote:
| It's interesting because the whole ice cap as we know it is
| around 120k years ago which I don't consider the long ago on
| human development scale. This also appears to mean that in
| the past 120K there wasn't a polar ice cap. I read that as
| the worst case scenario we should be using for long term
| planning. This also may help determine how fast the ice was
| built and how fast it will melt.
|
| I'm completely an armchair ponderer.
| lumost wrote:
| This will also assuredly fuel some interesting ideas about
| the origin of the Piri Reis map. A 120k year old ice sheet
| could mean that humans once lived on Antarctica.
|
| It does make one wonder if any ancient sea fearing humans
| happened to carve a world map into a durable material such
| as granite which could have survived until the modern
| historic era. Maybe such a map, or other mythological
| artifact fueld the Roman idea of Terra Australis Incognita
|
| /End rampant unsupported armchair speculation
|
| https://en.wikipedia.org/wiki/Piri_Reis_map
|
| https://en.wikipedia.org/wiki/Terra_Australis
| detourdog wrote:
| The Polynesians used stick maps to identify currents and
| land masses relative positions.
|
| With no evidence I believe navigation cues were built
| into the vessel. By keeping celestial bodies aligned with
| marks on the vessel one can achieve a seasonal calendar
| as well as documentation on how to modify the
| configuration for the next leg of the journey.
| contingencies wrote:
| IIRC the 'maps' made of organic materials were very much
| a rarity slash teaching aid for the later incarnations of
| traditional navigation cultures of the Pacific which we
| have surviving material on. Mostly they used mental maps,
| and of course the most sensitive instruments available at
| the time ... at least one example of which was hanging
| their balls off the edge of the canoe to see if they
| could detect a temperature shift. A good book on the
| subject is _We: The Navigators_ though it draws only from
| one area.
|
| Source: Have a Pacific art collection, have been to most
| of the major museums on the subject, interested in
| sailing, authored some of the Wikipedia (featured)
| articles on related watercraft.
| detourdog wrote:
| Yes, I would believe that some as fragile as the stick
| maps was no way to cross an ocean.
|
| What I think is interesting is the physical
| representation of an oral tradition. This is different
| than writing as employed today.
| contingencies wrote:
| Yep. All art is interesting for its relative flattening
| of multi-dimensional realities in to lesser-dimensional
| representations. Key concerns for the navigators were
| signals such as migration patterns, seaweed and other
| flotsam drift currents, temperatures of said currents,
| star positions, wave qualities, dominant wind directions,
| conditions and precipitation and cloud over seasons.
| These dynamic realities cannot be flattened in to any
| standard two dimensional representations even today, yet
| often emanate from or are disturbed by the often-tiny
| landmasses they would specify as origin, destination or
| reference points within the navigation problem. In the
| same way modern navigation uses multi-layered systems
| like bathymetric maps, local depth sensors, RADAR, GPS
| and navigation lights to provide orientation and safe
| passage amongst static and dynamic obstacles, so too the
| traditional navigators combined layers of sensory input
| considered too subtle for modern systems yet potentially
| equally effective in their place and season.
| detourdog wrote:
| Probably the migratory patterns were as import at as any
| other reason to travel.
|
| What I seem to be noticing is that the ancients used
| calculus all the time but it was the geometric tools that
| they used.
|
| This gave technology a form.
|
| Arabic numerals made tabular data more useful leading to
| the more number based tools.
|
| This seems to have removed the form from technology.
| renegade-otter wrote:
| Maybe humans become more developed because it got colder?
| Even on a country and global scale, the south is usually
| "behind" the north. It's hot, no one wants to do anything.
|
| The American south (Arizona, Florida) were tiny and
| unimportant until air conditioning entered the chat.
| Phoenix was at 100 thousand people in the fifties.
|
| The cold makes us think, the cold make us survive, keeps us
| on the edge - where we need to be. Respek the cold!
| lukev wrote:
| This is pretty ahistorical. Most of the world's great
| civilizations have been from warmer climates. Northern
| Europe is an exception, not the norm.
| pclmulqdq wrote:
| All of the world's "great" civilizations come from places
| with strong seasonality. The ones that didn't have
| winters had flooding seasons and dry seasons. Some of
| them had both. It also doesn't need to be bitterly cold
| for winter to have an effect on crops.
|
| Sumeria and Egypt both had seasonal flooding. Italy and
| Greece have winters that are cold enough to disrupt
| agriculture. The Aztecs and Mayans had seasonal floods.
| The ancient Chinese empires had both. Japan has winters.
| The list goes on.
| pavlov wrote:
| On the other hand there's something to be said for a
| comfortable climate that leaves people with time to think
| when the everyday isn't a constant complex struggle.
|
| The Inuits of Greenland and Sami people of Lapland didn't
| have Aristotle or Confucius.
| detourdog wrote:
| That is only due to writing. I always felt that the high
| latitude civilizations led to technological development
| due to the high risk and high solitude.
| downWidOutaFite wrote:
| It's not scientifically interesting, the glacial-interglacial
| cycles are pretty well established. I'm guessing they're
| trying to insinuate some climate change minimalism argument.
| mensetmanusman wrote:
| It's interesting to know how far back in time the ice will
| allow them to analyze once they get to the base.
| [deleted]
| rolph wrote:
| the drilling allows sampling of environmental components over
| extended period of time. this meas a historic record of,
| gases, ash, soot, pollen, spores, silt, insects, plant
| animals, metals, salts.....
| robertlagrant wrote:
| [flagged]
| WhitneyLand wrote:
| I'm not aware of any data that supports humans 120k years ago
| having a significant impact on the earths climate.
|
| I think even our ability to start fire at will is
| conclusively known to be only ~50,000 years ago.
| detourdog wrote:
| I always wonder about that natural fission reactor in
| Gabon. They discovered the Uranium was pre depleted in
| particular mines.
|
| https://en.wikipedia.org/wiki/Oklo_Mine
|
| Fun to imagine the possibilities.
| angiosperm wrote:
| That was more than a billion years ago, so no.
| detourdog wrote:
| I'll take a risk and be skeptical of that claim and see
| how my life turns out.
| hutzlibu wrote:
| "Claims for the earliest definitive evidence of control of
| fire by a member of Homo range from 1.7 to 2.0 million
| years ago "
|
| https://en.m.wikipedia.org/wiki/Control_of_fire_by_early_hu
| m...
|
| You don't need to be able to start a fire, when you keep
| the fire burning all the time. And you can do that, once
| you control the fire and figure out the difference between
| dry and wet wood.
|
| Also humans are the dominating species on land since quite
| a while. Hunting certain species to extinctiom has certain
| effects on the local ecosystem and globally on the global
| climate. It all adds up.
|
| But things surely changed in dimension since
| industrialisation.
| dekhn wrote:
| People had fire in those times but it's extremely
| unlikely they produced enough CO2 to have an
| anthropogenic impact on the climate leading to large-
| scale temperature changes.
|
| I'm not sure what your perspective on this situation is
| but I think the case for modern anthropogenic climate
| change with deleterious effects is based on a wide range
| of different evidence, and a careful accumulation of
| facts and analysis. Simply pointing out that humans had
| fire 2Mya doesn't change the general conclusion about
| today.
| londons_explore wrote:
| I suspect gr main change caused by humans >100 k years
| ago will be wiping out various species and starting fires
| in seasons and places where fires wouldn't normally start
| (eg. In places without dry lightning or volcanoes - the
| only two other ways fires naturally start)
| gameman144 wrote:
| Just in case this is just a case of word confusion (which
| I've had before), "anthropogenic" means "caused by humans",
| not "occurring at the same time as humans".
| albert_e wrote:
| what is the risk of uncovering ancient viruses and bacteria from
| permafrost that we don't have immunity to
| hannasanarion wrote:
| Very very very low. Bacteria and viruses are normally very
| sensitive to their hosts, they have a kind of symbiosis that
| means they can't just arbitrarily infect any species they bump
| into.
|
| Jumping between species does happen, and when it happens it can
| be a big problem (see COVID-19, Swine Flu), but there is
| something like _100 million_ different virus species out there
| [1], and _only 200_ or so are able to infect humans [2].
| Despite constant interaction between people and all other
| species of viral host all over the globe, and millions of brand
| new new virus exposures daily, jumps are still so rare that
| they are decade-defining when they happen.
|
| 1. https://virology.ws/2013/09/06/how-many-viruses-on-earth/
|
| 2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3427559/
| Clamchop wrote:
| I read a book, How to Clone a Mammoth, by ancient DNA
| researcher Beth Shapiro.
|
| If what she wrote holds true deep in these glaciers (which take
| a long time to form so they presumably weren't always buried so
| deep), then the answer to what the risk may be is "very
| remote". DNA and RNA disintegrates into very small tatters
| pretty easily, turns out, frustrating the reconstruction of
| ancient genomes. Bacteria are definitely dead on multiple
| counts and viruses will be shredded.
| Archelaos wrote:
| Here is an article from 2021 that covers that topic:
|
| https://link.springer.com/article/10.1007/s42398-021-00184-8
|
| From the conclusions: "... as shown by recent outbreaks of
| diseases caused by supposed to be extinct microbial pathogens
| immured in glacial ice for centuries, there is a serious risk
| for future epidemics (or even pandemics) to happen more often."
| anon25783 wrote:
| Negligible. You're far more likely to fall ill from bacteria in
| your garbage disposal or fungi in your bathroom.
| mr-wendel wrote:
| If drilling big holes for scientific research is your thing, I
| suggest https://usoceandiscovery.org/wp-
| content/uploads/2016/06/Casc... as an interesting read about
| earthquakes and tsunamis.
|
| A quick summary: > Geophysical and hydrological
| observatories in sealed boreholes provide a powerful tool to
| understand the hydrology of crustal formations, a means measure
| the hydrologic signal from changes in volumetric strain, and a
| stable site for high quality seismic and geodetic
| instrumentation.
|
| This data is not just useful on its own, but also when correlated
| to other research. For example, 400+ years ago there was a large
| earthquake
| (https://en.wikipedia.org/wiki/1700_Cascadia_earthquake) off the
| US Pacific Northwest coast (and corresponding tsunami in Japan)
| that is referenced.
| almostnormal wrote:
| Two numbers from the article: The oldest ice is 120000 years old.
| The ice is moving at 58 m/years.
|
| If these numbers are correct the oldest ice has travelled almost
| 7000 km. Greenland isn't that large, and it did not shrink. The
| age estimate is probably correct.
|
| The speed must have been a lot lower in the past?
| ballenf wrote:
| [flagged]
| toshk wrote:
| I love humans.
|
| They somehow decided to start drilling, and not give up & get
| funding for 7 years.
|
| We are a crazy but exciting bunch of organisms.
| hk__2 wrote:
| That's because we are social animals. We tend to do things not
| only for ourselves, but also to contribute to the society we
| live in.
| uncletammy wrote:
| > We are a crazy but exciting bunch of organisms.
|
| I read this as "crazy but extinct bunch of organisms"
| mensetmanusman wrote:
| Also read extinct. Ha. Would be cool to know how to detect
| and exploit these speed reading induced recognition errors to
| write things that force people to slow down or go extinct :)
| holoduke wrote:
| Would it theoreticaly possible to find frozen animals 120.000
| years old with still intact DNA?
| dekhn wrote:
| The oldest frozen mastodon found is only 30K years ago.
|
| This isn't really "frozen animals" and everything was sort of
| mixed together so they had to compare remaining fragments to
| existing sequences:
|
| https://www.nytimes.com/2022/12/07/science/oldest-dna-greenl...
| sedatk wrote:
| Yeah, DNA in ice has a half-life of a million years. Seems very
| much possible.
| wwwtyro wrote:
| What does half-life mean in the context of DNA? One base pair
| corrupted / unrecoverable? Half of them?
| netcraft wrote:
| half life generally means that within the time frame 50% of
| the material will have been destroyed or changed.
|
| so it would mean that half of the dna might still be
| available after 1M years
| graycat wrote:
| To be meaningful, _half-life_ needs a Markov assumption,
| i.e., that the past and future are conditionally
| independent given the present. Or, more simply, at each
| _instant_ , forget the past and for predicting the future
| use only the present.
|
| Some interesting work in the many contexts where half-
| life works would be to say what the Markov property says
| about the mechanism of the _decay_ or whatever are trying
| to predict in the context.
| monocasa wrote:
| Half of them. Which is still useful in biological samples
| that have billions of copies.
| amelius wrote:
| Yeah, you can still assemble a genome even if strands are
| broken. In fact this is done all the time as the size of
| the strands going into DNA sequencers are often only 100s
| or maybe 1000s of basepairs.
| delecti wrote:
| Where are you getting that figure? Everything I had ever read
| on the subject puts the half-life at more like 500 (five-
| hundred) years. While doing a quick double-check for this
| comment, it seems there was one sample with the unexpectedly
| long observed half-life of 15,000 years, still a couple
| orders of magnitude less than a million years.
| https://en.wikipedia.org/wiki/Ancient_DNA#Non-human_aDNA
| Tagbert wrote:
| Preservation conditions might have some bearing.
|
| This recent news article suggests nematodes actually
| surviving after 46K years in permafrost.
| https://www.scientificamerican.com/article/46-000-year-
| old-w...
| sedatk wrote:
| That's room temperature. Frozen DNA is significantly more
| resilient. https://www.pnas.org/doi/10.1073/pnas.0702196104
| dekhn wrote:
| I'm not an expert in this area but I do know a fair amount
| on the subject. I believe the section you linked is out of
| date.
|
| The DNA we get back from old situations typically was
| preserved, by dryness/freezing, and it's still quite
| fragmentary. The actual "half life" of DNA is not that
| interesting- its the details of the DNA remnants that
| matter.
| tokai wrote:
| Not an animal, icecore, or that old, but ancient plants has
| been grown from seeds from permafrost.[0] So who knows what
| might be found and analyzed from all the icecores.
|
| [0] https://www.theguardian.com/world/2012/feb/21/russian-
| scient...
| AmericanOP wrote:
| [flagged]
| bagels wrote:
| I don't think this is a factual response. This appears to be
| some cartoon?
| AmericanOP wrote:
| Recent Netflix story arc about boxing a defrosted
| caveperson. I couldn't resist.
| mandmandam wrote:
| Not even a caveperson - a 200 million year old dude who
| fights tyrannosaurs.
|
| It's ridiculous and it's awesome.
| [deleted]
| roter wrote:
| At approximately the same depth drilled, Antarctica e.g. EPICA @
| Dome C yields _8_ interglacials [0].
|
| [0]
| https://en.wikipedia.org/wiki/European_Project_for_Ice_Corin...
| ChuckMcM wrote:
| This is a very important project. There is a joke in here about
| "why not wait 2 years for the ice to melt off if you wanted to
| look at the mud underneath?" But as the article states, _" 'This
| will change climate models because it redefines our basic
| understanding of how ice moves,' explains Dorthe Dahl-Jensen."_
| Much, if not the majority, of climate science is the creation of
| models (differential equations mostly) that describe the
| "response to influence" of the big chunks of things that cause
| the climate on the planet. The better the model, the better able
| we are to guess what will happen next (which is sorely needed in
| a system where you cannot control the input variables by
| declaration).
|
| One of the big unknowns in the model is "where will the clouds
| show up?" That unknown stems from our understanding of the water
| capacity of air by temperature, the increase in air temperature
| leads to the air holding more water, and water is the basis for
| cloud formation. If the clouds form "low" they increase albedo
| and create colder temperatures, if they form "high" they act as a
| semi-mirrored surface and reflect light that has been reflected
| from the surface back down for another shot at generating heat.
|
| Much of the IPCC's work has been done in MATLAB[1,2] so if you
| have a reasonably powerful workstation you can play around with
| various initial conditions and settings yourself to see what
| might happen in the future.
|
| No matter what the far future holds, the near future holds more
| violent storms as storms are powered by the temperature
| differentials of the air, land, and sea.
|
| It is of note (for me, probably not for many others) that we
| don't have good models for how an ice age starts. There are a few
| papers that talk about ice ages being a response to warming (hit
| a tipping point, generate clouds, and get a "nuclear winter"
| scenario without the nuclear part). But much of the nuclear
| winter work has been refined and that scenario is generally
| considered unlikely AFAICT from what people seem to be publishing
| these days. Turco's work[3] and things that cite it are a good
| jumping off point if you want to read up on that. It isn't
| perfect because smoke/soot are not clouds (different albedo
| numbers, different cooling attributes) but the accumulation and
| dispersion of atmospheric obstructions is solid stuff.
|
| [1] Some code and information used to generate plots in the IPCC
| reports -- https://github.com/IPCC-WG1/Chapter-9
|
| [2] Mathworks trying to get you to buy their climate data toolbox
| -- https://www.mathworks.com/discovery/climate-stress-
| testing.h...
|
| [3] Climate and Smoke: an Appraisal of Nuclear Winter --
| https://www.science.org/doi/abs/10.1126/science.11538069
| samstave wrote:
| It would seem to me, that the best way to do long-scale climate
| models of a body ; knowing its composition in layers over time
| is really important to be able to calculate the flow of the
| layers of composition as particles.
|
| Think of the experiment of light as wave/particle...
|
| Glacial/geological scales operate as thus ; as physical masses
| of particles, but move in more wave-like manners - so you'll
| have material suspended and located in the overall mass based
| on how they were consumed as a particle, but the characterists
| of the glacial mass will appear to be acting like fluid waves.
|
| So maybe if you know the timeline of a glacial flow, you can
| predict where the most particulate-glacial-slurry is held (thus
| minerals, biologic wash off in certain events etc.
| anigbrowl wrote:
| A lot of modeling is moving toward Julia, so if you don't want
| to give money to Mathworks here are some alternatives:
| https://juliaclimate.github.io/Notebooks/
| javajosh wrote:
| Note that the individual license for Matlab is $149/year [0],
| which isn't crazy IMHO.
|
| 0 - https://www.mathworks.com/pricing-
| licensing.html?prodcode=ML...
| __MatrixMan__ wrote:
| Given the added burdens of...
|
| - managing licenses across multiple devices
|
| - limiting the people you can share code with to ones that
| are willing to deal with licenses
|
| - budgeting for an ongoing subscription / renewing as
| needed
|
| ...I'd say that even $10/year is too much. Ecosystems that
| create collaboration barriers like these are no place for
| important work.
| anigbrowl wrote:
| Agreed, it's sofa change for an institution. But I remember
| cost being a big obstacle when I first wanted to learn
| serious programming around 1990, so I feel like free
| programming languages are better.
| analog31 wrote:
| The institutional cost is more AFAIK, but should still be
| pocket change -- one productive week pays for it. But the
| price is just high enough to trigger all sorts of weird
| management wastes. Especially if you envision wanting
| more than one installation, or are in an austerity-
| culture organization.
|
| While you're dealing with the time and aggravation of
| budget approval and recurring license management, I've
| got my Python and Arduino toolchains installed on
| literally every computer that I touch: At home, my
| office, the labs, etc.
| cstejerean wrote:
| Without any toolboxes though, and you'd typically need a
| handful of those depending on what field you're working in
| and that's another $45 per toolbox. But also anyone just
| getting started may not know which toolboxes they need
| upfront which increases the uncertainty about the price.
|
| I really wish they had a more reasonably priced all you can
| eat home license that included all toolboxes.
| ChuckMcM wrote:
| I have moved all my "matlab like" work (mostly signal
| processing) into Octave for that same reason.
| tetris11 wrote:
| GNU Octave is surprisingly good. I had old MATLAB work from
| university that I wanted to revisit for teaching purposes,
| and was surprised by the lockout imposed by the pricing
| model of MathWorks[1] (120 EUR for an individual license,
| 260 EUR for teaching)
|
| 1: https://nl.mathworks.com/pricing-
| licensing.html?prodcode=ML&...
| earthscienceman wrote:
| You're adding important context but I would like to clarify
| something to highlight just how complex climate change really
| is. I also am going to make a few related comments, as I do
| most of my research on melt in Greenland. Full disclosure: I do
| know some of the people in this article but I have never been
| to eGRIP specifically. I will be in Greenland in a week nearby
| though. No matter what the far future holds,
| the near future holds more violent storms as storms are powered
| by the temperature differentials of the air, land, and sea.
|
| This is true, sort of. There's a lot nuance needed for this
| broad statement. In particular, "Arctic amplification" means
| that the pole-to-equator temperature gradient is actually
| weakening. If you were inclined to believe the covid lab leak
| theory you would also be inclined to jump on this and say "then
| the extreme storms are nonsense". However, what's really
| happening is that the waves in the upper atmosphere ("Rossby
| waves") are getting more wave-y. Which is really saying that
| additional energy from CO2 warming is resulting in stronger
| transport and more significant variability. It's _not_
| resulting in larger gradients. Although sometimes the gradients
| are also extreme.
|
| Climate is a question of two things, time scales and spatial
| scales. Dumping a bunch of CO2 in the atmosphere messes with
| both.
|
| I also want to point out that this isn't the first time a core
| has been dug to the bed of the Greenland ice sheet. It's also
| not the second. Some comments seem to be implying this. I have
| a bad taste for science reporting/announcements like this that
| fail to provide context. Of course this is important work but
| it's following up and improving on several previous deep core
| drilling experiments. We still have many samples from these
| previous cores. This is still a very good thing to research and
| will hopefully provide important new insight. But there is
| significant previous work it builds on [1]. And the title kind
| is vague enough that outsiders/the public might not understand
| that.
|
| Also also, to be a little vitriolic, the IPCC Matlab code is a
| crime against humanity and fuck Mathworks.
|
| [1]https://www.sciencedaily.com/releases/2021/03/210315165639.h
| ...
| photochemsyn wrote:
| I'd add that although the intergrated yearly _average_ pole-
| to-equator gradient is indeed weakening, in terms of extreme
| storms this probably doesn 't matter since the gradient is
| still very strong in winter months in the Northern
| Hemisphere, and if you pump the atmosphere with more water
| vapor from the tropics, then intense seasonal storms and
| extreme flooding can be expected for at least half the year
| in the Northern Hemisphere - and in midlatitudes, the east-
| west motion of frontal systems complicates the issue further
| (though it seems increased water vapor is driving that engine
| more than anything else).
|
| The Artic amplification effect appears to be having a big
| effect in the summer months as the decreased gradient allows
| the polar jet stream to meander southwards, resulting in
| random persistent blocking events (responsible for recent
| spate of heat waves) related to Arctic amplification effects
| on the jet stream (in both hemispheres). Good discussion
| here:
|
| https://www.carbonbrief.org/jet-stream-is-climate-change-
| cau...
| sleet_spotter wrote:
| Also work on ice, though not with cores. Just 2nd'ing this as
| being a great point. Arctic amplification is fascinating and
| IMO understudied relative to its importance.
|
| The distinction I believe the article is trying to make
| around the "first-core-to-ground" sentiment, is that this is
| the first time a core has been drilled through the full
| thickness of an ice *stream*. These are regions of an ice
| sheet with very rapidly moving ice. Ice loss from ice streams
| may have a larger and more immediate impact on sea level than
| other regions in Greenland and Antarctica. However, I do not
| actually know whether this is the first core drill ed through
| an ice stream, but I'm assuming that was the article's
| intent.
| wing-_-nuts wrote:
| Wow, thanks for the links, this is _really_ neat
| aeroman wrote:
| As a "cloud person", I just want to add a few things to the
| description of how clouds affect the climate (and why high
| clouds have a wamring effect).
|
| All clouds are white, so they all reflect sunlight back into
| space (during the day), cooling the Earth.
|
| All clouds are (almost) black in the infra-red, meaning the
| amount of energy they emit in the infra-red is determined by
| their temperature. Colder clouds emit less energy.
|
| Almost all clouds are colder than the surface beneath them,
| which means they emit less infra-red energy to space than a
| clear day would. This reduces the amount of energy the Earth
| emits to space, so warming the climate.
|
| High clouds are colder than low clouds, so have a stronger
| warming effect.
|
| In summary:
|
| Low clouds - Reflect sunlight (cooling), don't trap much infra-
| red (little warming)- Net: Cooling effect
|
| High clouds - Reflect sunlight (cooling), trap lots of infra-
| red (stronger warming) - Net: Warming effect
| photochemsyn wrote:
| This IR satellite view of clouds and water vapor centered
| over N/S America is pretty nice. You can also see the daily
| pulse of cloud formation over the Amazon rainforest:
|
| https://youtu.be/f7QttjGu628?t=142
| kfrzcode wrote:
| I will give you the benefit of doubt given it's Hacker News
| you likely are an expert, but this feels like one of those
| "sounds too intuitive to be that simple" type complex
| factors. Any literature on the topic from which I can improve
| my understand?
| Ilnsk wrote:
| I wish I were a cloud person.
| Insanity wrote:
| When I read that first sentence, I thought "what has cloud
| (software) to do with this"
| Nevermark wrote:
| Not series, maybe a bit serious:
|
| Cloud computing energy use appears to be on an
| exponential trend driven by general trends (all things
| automated), with new forms of automation compounding
| competitive pressures (deep learning models quickly
| getting larger, more powerful, more useful, and more
| versatile in a way erasing many lines holding back past
| competition.)
|
| At some point, it seems inevitable that computing usage
| will be a first level climate driver, regardless of how
| green the energy is.
|
| Harnessing orbital solar, fission and fusion power, may
| solve the CO2 energy problem, without requiring us to
| steal the biosphere's energy needs, but will eventually
| create a massive waste heat energy problem.
|
| Unless we find someway to efficiently transfer mass
| amounts of heat energy off of Earth.
|
| Or we eventually limit computing on Earth, and export
| that to the Moon and beyond.
| almostnormal wrote:
| * * *
| crznp wrote:
| That's interesting. How relevant is energy transport in
| comparison to the optical effects?
|
| Eg: my understanding is that hurricanes are net cooling
| because they transport heat from the ocean surface to the
| upper atmosphere. Presumably the same can be said for
| cumulonimbus/thunderheads? Or perhaps it is more relevant
| when they form in the day and when they dissipate at night?
| m3kw9 wrote:
| Have a drink?
| [deleted]
| bobske3 wrote:
| At the mountains of madness
| CrzyLngPwd wrote:
| [flagged]
| samstave wrote:
| There is a design for an ice-melting-slurry-bot that could be
| made, where the outer diameter of the bore is melted by
| heat/lasers - where the lasers/heat is also projected into a cone
| at the point of the bore-ing machine, where the center pipe is a
| vacuum to slurp up the slurry as it melts the ice around the
| bore-head...
| hanniabu wrote:
| That would ruin the core samples
| samstave wrote:
| We dont want the core samples intact (we want to kill
| microbiologics on the way down to the goal, which is the
| crust and determination for other vacuous caverns under the
| ice, via both vertical and horiz boring. and cameras in
| crytal lenses to withstand the heat or polarize against the
| lightwaves of the lasers such that they are clear and a good
| image can be seen.
|
| /Sci-fi..
|
| My original comment is my idea based on the 1960s patents for
| nuclear tunnel boring machines which use the reactor heat to
| exchange the tunnel walls to molten glass... (And I am really
| into DUMBS - as are many)
|
| https://patents.google.com/patent/US3885832A/en
|
| There are a lot of patents like this - so dont think this
| line of thought was abandoned, Hello Musk's Boring company...
| Good thing hes connecting State on a Deep level.
| BenjiWiebe wrote:
| You aren't going to be able to vacuum slurry up from several km
| down.
| bequanna wrote:
| Even with a very small diameter hose/pipe?
| qbrass wrote:
| The smaller pipe has less water in it, but the surface area
| the vacuum can act on is also smaller so the column of
| water equals out the same as with the larger pipe.
|
| At sea level, that's about 30 feet deep. If you want to
| bring water up from deeper, you have to move the pump down
| the well and push the water up the pipe instead of trying
| to suck water up like the pipe's a straw.
| dclowd9901 wrote:
| I've always wondered: what do they do if the shaft snaps
| somewhere in the middle?
| aio2 wrote:
| This is more for oil drilling, but this is a possibility.
| https://www.drillingformulas.com/fishing-drill-pipe-procedur...
| sleet_spotter wrote:
| I'm not totally sure how systems work for drilling this deep,
| but typically ice core setups attach the coring apparatus to
| the surface via a cable that is spooled by a winch. The cable
| itself ends up being the heaviest part of the system.
| sdfghswe wrote:
| Can't believe they don't show a photo of what appears to be a 10
| meter in diameter, 2.7km deep hole.
| FredPret wrote:
| There's a bright future in big holes.
|
| Imagine what we can get our hands on if we could find a nice,
| cheap way to dig 10+ km down all over the place. The mantle is
| 2000+km thick. Our deepest mines are 3-4 km deep.
|
| We could also harvest a ton of heat this way - and maybe even
| use it for garbage disposal. Master Of Orion 2 had the Deep
| Core Mines and Core Waste Dumps - maybe that's the way to go!
| TechBro8615 wrote:
| Is the idea of using a big hole for garbage disposal that we
| would dump the garbage into the molten core and let it burn?
| Or is it more about using the hole as a really deep landfill?
| hinkley wrote:
| Do you know what a hole from the surface to the molten core
| is called?
|
| An active volcano.
| TechBro8615 wrote:
| Yeah, I realized that after I commented, and when I
| googled it, the Quora answer I got basically _boiled down
| to_ "you don't know what will come back out."
| hinkley wrote:
| I always thought that was the scary part of a nuclear
| plant meltdown until I watch Chernobyl and realized
| poisoning the aquifer for a million years is a much more
| likely scenario.
| FredPret wrote:
| Scary thought but you'd (have to) stop digging way above
| the molten part.
|
| It heats up way above 100C long before you get there,
| which should be plenty for geothermal energy.
|
| I wonder if sustained high temperature exposure would
| gradually decompose plastic / toxic waste / other bad
| things into less harmful components.
|
| Of course, heavy elements came from down there, so it's
| probably not an issue to dump them back down. Just stay
| well clear of the water table!
|
| I am of course not a geologist, and it'd be interesting
| if one could give a perspective on this.
| hinkley wrote:
| I'm not sure how tall a column of water you need to
| trigger supercritical water oxidation, but the problem
| would be getting the oxygen down there.
|
| Better to do that stuff at the surface, I think.
| tokai wrote:
| Its more like 5cm in diameter.
| TheRealPomax wrote:
| Ice cores are a few inches across. The photo at the top of the
| article is not of the drill hole but of the hole they had to
| dig in the snow to get to the ice they actually drilled.
|
| See the photo of the final ice core [1] to see how miniscule
| the actual drill hole is.
|
| [1] https://science.ku.dk/english/press/news/2023/pay-dirt-
| for-i...
| blackkettle wrote:
| The article definitely makes it sound like they had "boots on
| the ground". There's a picture of muddy boots and the caption
| says they are covered in ancient mud.
| TheRealPomax wrote:
| You need to clear a lot of snow before you can stand on the
| ice that you're drilling in (You can't drill straight if
| your rig's sitting on snow, you need to dig until you hit
| solid ground, and in this case the ground is ice). That's
| the "boots on the ground" part. They were physically there
| to do the drilling (as opposed to giant automated core
| drillers such as DISC[1], which don't require "boots on the
| ground" so much as they just require one or more operators
| to oversee operation)
|
| The ancient mud's from hauling up the ice cores, not from
| standing 3 kilometers deep in a giant hole.
|
| [1] https://icedrill.org/equipment/deep-ice-sheet-coring-
| drill
| tokai wrote:
| That mud came up with the last core.
| Giorgi wrote:
| Why is is black and white though? also - how do they transfer
| energy to drill down 2.7km? or how the hell does it work?
| TheRealPomax wrote:
| See other comment, and "that's a fun thing to check youtube
| for", respectively =)
| tgamma wrote:
| As mentioned in the article, the core was handled under red
| light to prevent any potential damage. Perhaps the decision
| to convert the photograph to black and white was made
| because otherwise it would have been black and red.
| dewey wrote:
| It's a bit hidden but there's at least a few cool pictures in
| the "Facts about the EGRIP camp" section (Click the + icon).
|
| There you can see that the actual hole is ~10cm in diameter and
| the actual drilling site under the snow.
| jtsiskin wrote:
| Or a video dropping a rock into it
| hinkley wrote:
| The camera wouldn't take the picture, and then several of the
| scientists had to be sedated as they started acting strangely.
| j1elo wrote:
| As long as they don't come up with schematics to build a
| white Marker...
| hinkley wrote:
| For all we know that could be psyops by Lovecraft. Maybe
| it's not a white marker, it's a blue beacon.
| giantrobot wrote:
| What an ice hole.
| JimtheCoder wrote:
| To be fair, is a photo of a hole that interesting?
| peoplearepeople wrote:
| yes, people love pictures
| mbfg wrote:
| Here's a picture of a cat sitting on the hole.
| iknowSFR wrote:
| [flagged]
| CrzyLngPwd wrote:
| Yes, but they may share wetness this one does not share the
| warmth.
| jprd wrote:
| https://old.reddit.com/r/trypophobia/
| cancerboii wrote:
| [dead]
| robotnikman wrote:
| >electromechanical drill designed to take 122 mm (4.8-inch)
| diameter ice cores
|
| Interesting that they choose 122mm as the core size when
| designing the drill. It makes me wonder if its built from a
| decommissioned and repurposed 122mm artillery gun barrel.
| johnnyApplePRNG wrote:
| That's a rate of about 4.3 centimeters per hour.
|
| Can anybody elaborate as to why this process takes so long?
| klyrs wrote:
| I've never drilled a hole with 10m diameter before, but I
| imagine they've been more careful about taking and studying
| cores than you were.
| Zamiel_Snawley wrote:
| Surely you mean 10cm?
| klyrs wrote:
| My word. I and at least one other poster here were misled
| by the picture at the top of the article.
|
| But, for whatever it's worth, a trip to Wikipedia tells me
| that they took 2 years off, due to covid.
| joshvm wrote:
| It's more realistic to say that covid caused logistics
| issue two summers in a row. The first summer was
| presumably 2020 when almost every country locked down. In
| 2021 things weren't much better and the various polar
| programs were dealing with both caution and a backlog of
| issues from the previous year.
|
| The actual downtime may have been significantly less than
| 24 months but still could have killed progress for 36.
| There's a pretty small window that you can deploy for
| these sorts of operations.
| roter wrote:
| Did you store the tube of ice?
| sleet_spotter wrote:
| As the hole gets deeper, the amount of time to bring up core
| sections and send the drill back down become significant. That
| combined with the previously mentioned short field season.
| Drilling more than a few hundred meters becomes very difficult
| logistically as well, especially in such a remote setting.
| mywittyname wrote:
| Like fetching the n-th element from a linked list by starting
| at the first node.
| foota wrote:
| Who knew, drilling is O(N^2)
| hcnews wrote:
| It's not O(N^2) is it? It can be a continuous line of ice
| being pushed up. Depending on the weight bearing ability of
| the lift and digging capacity, you would figure out a fixed
| distance after which you would place the buckets to carry
| up the ice.
|
| Its an interesting interview question at the very least.
| (More complications arise as and how you get deeper into
| the ice).
| [deleted]
| altacc wrote:
| It's not a continuous 24/7/365 process. They have a drilling
| season each year, I believe about 6-8 weeks, have drilled at 2
| different sites and been interrupted by the pandemic.
| jppope wrote:
| why was ice drilling interrupted by the pandemic?
| applied_heat wrote:
| Getting supplies such as food and shift changeovers?
| eastbound wrote:
| Well it was forbidden to walk outdoors. People were fined
| by helicopter is all Western countries for walking alone in
| forests, dunes or farmland.
| lexicality wrote:
| it's a very high aspect ratio hole (267:1) so they have to
| peck-drill it and it takes a very long time to lift the
| drillbit to remove the swarf from the end
| [deleted]
| drKarl wrote:
| I believe the deeper the layer of ice, the thougher it is, so
| at the surface is relatively easy to drill but at those depths
| it might be like drilling on steel.
| stainablesteel wrote:
| so how do they know its not just a big rock covered in frozen mud
| with more ice below it
| ultrablack wrote:
| [flagged]
| chrisco255 wrote:
| Given that Greenland regularly gains surface mass, even this
| year gaining close to 50 gigatons as of June 20th:
| https://nsidc.org/greenland-
| today/files/2023/06/SMB_Fig3_15J..., you might have to wait a
| few more millenia or even another 100K before the next
| interglacial.
| fg__ wrote:
| [flagged]
| marcosdumay wrote:
| Please, if the title is going to be that, at least remove the
| capitalization from that "m", so it represents an unity instead
| of "millions of something undisclosed".
| dang wrote:
| Submitted title was "Researchers reached the bottom of ice
| sheet at -2670m after 7 years of drilling". I've reverted to
| the article title now, or rather a slightly rewritten version
| to omit the linkbait.
|
| Our software did screw up the m->M thing. Sorry!
| porphyra wrote:
| Also, a space is needed.
|
| > The numerical value always precedes the unit and a space is
| always used to separate the unit from the number.
|
| The International System of Units. 9th edition, section 5.4.3,
| page 149. https://www.bipm.org/en/publications/si-brochure
| JimtheCoder wrote:
| "so it represents an unity instead"
|
| If you are going to be pedantic, that "an" should be an "a",
| no?
| ksd482 wrote:
| That's what I was thinking, yes.
|
| You have to think HOW you pronounce the word. The 'u' in
| "unity" is pronounced as "you" which starts with a consonant.
| Hence, you use 'a' not "an".
| lopis wrote:
| I've always wondered this, as a non English native speaker.
| You could also say the "u" in unity is pronounced as "iu"
| which starts with a vowel and sounds the same as "you", so
| your reasoning sounds incorrect. Perhaps a better
| explanation is that the "iu" diphthong is already paired
| together, so attaching it to the "an" sound to form "aniu"
| doesn't roll off the tongue as well.
| hunter2_ wrote:
| Correct, this particular diphthong and the substitution
| of "an" for "a" serve the same exact function, so having
| both would be redundant. If we were to look at a word
| that starts with u but doesn't have the diphthong, such
| as Ubuntu, then "an" is used.
| hunter2_ wrote:
| I think unity is just a typo for unit, not that that
| changes this discussion.
| tokai wrote:
| But Y is a vowel?
| chungy wrote:
| English rules for using "a" or "an" depend on sounds used
| in the next word, not particular letters. "A unit" and
| "An hour" are easy examples that might trip people up
| when focused on the letters used in spelling, but if you
| sound it out, you can probably work out what sounds best.
| ad133 wrote:
| And of course it's even more complex when you mix UK vs
| US English:
|
| - an herb (US), where the "h" is silent
|
| - a herb (UK)
|
| Cue confusion about "an historic".
| lcnPylGDnU4H9OF wrote:
| Yeah, occasionally. The previous sentence uses it as
| both.
| JimtheCoder wrote:
| Sometimes...
| stronglikedan wrote:
| Only when your mouth parts move a certain way to pronouce
| it: https://www.youtube.com/watch?v=I6As7KhrFQ4
| giuliomagnifico wrote:
| Hacker News capitalized the "M" by itself.
| 6D794163636F756 wrote:
| Thank you for pointing this out. I thought it was referring to
| the age of the samples taken before reading your comment. It
| made the abstract less disappointing.
| marcosdumay wrote:
| I only clicked on the article because I thought it was the
| age of the samples too.
| adolph wrote:
| If something has a negative age, does that mean it is from
| the future?
| stefncb wrote:
| I can't tell if you're joking, but negative numbers are
| used to represent years BC.
| adolph wrote:
| It responds to the comment "I only clicked on the article
| because I thought it was the age of the samples too." Age
| is "The length of time that a person or thing has
| existed." AD and BC are both absolute values from a zero
| point, both positive ("1 BC is year 0, 45 BC is year -44"
| [0]). A relative chronological dating by some
| phenomenological method such as radiocarbon or
| thermolumenescence might establish a negative date
| relative to some other known benchmark [1].
|
| How might something dated from the future be found? I'm
| not certain, but maybe it has to do with aliens that are
| all the rage nowadays.
|
| If I were 12 years old, I would have been born 12 years
| ago. 2023 - 12 ----
| 2011
|
| If I were -12 years old, I would be born 12 years from
| now. 2023 - -12 ----
| 2035
|
| 0. https://en.wikipedia.org/wiki/Anno_Domini
|
| 1. https://en.wikipedia.org/wiki/Chronological_dating
| Scofield67 wrote:
| [flagged]
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