5 ms·

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.

• orangepurple 3y ago
  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.
  • ricardobeat 3y ago
    Nuclear facilities seem pretty fragile / demanding, I doubt one would survive any kind of apocalyptic event. The infrastructure supporting it will be gone.
    • fullstackchris 3y ago
      isnt that the case with any advanced technology? (including wind and solar)
      • dredmorbius 3y ago
        Yes. Though as a corollary, such an event would be civilisation-ending in any regard. It's also ... highly rare. Somewhere in the 1 in a million to 100 million year range, which is to say, not only longer than the planning horizon of most human institutions, but well outside the existence of the human species for the most part. It's also well beyond the available supply of terrestrially-minable uranium,[1] and possibly of ocean-extracted uranium,[2] and thorium[3]. Breeders might be another option, though I've seen no substantive estimates of total fuel availability for that case either.[4] But as an argument favouring nuclear over other energy options ... this is pretty silly, really. About the only viable defence against such a risk would be, and I say this as someone who's markedly pessimistic on space colonisation, independent and self-sufficient habitations off-Earth: YACP.[5] ________________________________ Notes: 1. If we relied on naturally-occurring terrestrially-mined uranium for all present human energy consumption ... supplies would last fewer than two decades. This is seldom mentioned by nuclear advocates. 2. This offers a potentially much larger supply, as uranium is present as a solute in seawater, but viable industrial-scale extraction is unproven and would require filtering vast quantities of seawater. 3. Thorium is reasonably abundant, though I'm not quite sure how abundant. Thorium-based reactors are not much used, and the concept of molten-salt reactors (MSR) which gained some popularity in the past decade ... faces some very significant engineering hurdles. Managing high-temperature highly-corrosive radioactive salts is ... challenging. 4. Breeders produce plutonium. And now you have two, or more, problems. 5. Yet Another Challenging Proposition.
    • orangepurple 3y ago
      Nuclear facilities can probably continue to operate amid persistent cloud cover and ash. Wind turbines and solar can not. Agriculture would have to shift artificially lit greenhouses.
  • XorNot 3y ago
    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).
  • dredmorbius 3y ago
    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.
    • zosima 3y ago
      Bigger problems than no power in the worst year imaginable. Give me a break.
      • sanderjd 3y ago
        Yes, no agriculture is an even bigger problem than no power.
        • zosima 3y ago
          You don't think modern agriculture and energy are intimately related? I'm honestly a bit shocked.
          • sanderjd 3y ago
            I do think they are, but it's also (obviously) the case that if an eruption blotted out the sun and disrupted wind currents, having the ability to keep generating power would not help much because the plants and animals we eat would all die. And what's with the weird tone? It's a super banal point that our food requires sun. I highly doubt you're "shocked" by it.
      • Server6 3y ago
        Yeah. Crop failures and famine. Way bigger problem.
        • dredmorbius 3y ago
          And depending on the eruption, for anywhere from years to centuries or longer.
• angiosperm 3y ago
  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 3y ago
    Wikipedia suggests this is not definitive, and maybe not even evidence: https://en.wikipedia.org/wiki/Cerutti_Mastodon_site#Criticism https://en.wikipedia.org/wiki/Cerutti_Mastodon_site#Criticis... This article is much more sympathetic (and also a fun read): https://www.latimes.com/local/california/la-me-cerutti-mastodon-20171222-htmlstory.html https://www.latimes.com/local/california/la-me-cerutti-masto... I’m no expert but it seems like this is still a controversial idea.
    • angiosperm 3y ago
      Wikipedia over-represents the opinions of retired professors. As Max Planck wrote, "Science advances one funeral at a time". The usual shallow, reflexive objection is that the bones must have been broken and carefully re-arranged via being run over by construction equipment. This absurd suggestion has been very thoroughly demolished without assistance from construction equipment. It is hard for dump truck tires to produce green-stick fractures in 130,000-year-old bone, or to put bone fragments into the pores of stones and then move them yards away, all while underground.
• wheelerof4te 3y ago
  "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.
  • mschuster91 3y ago
    > 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_eruptions https://en.wikipedia.org/wiki/List_of_large_volcanic_eruptio...
    • pmayrgundter 3y ago
      Here's a study: The size and frequency of the largest explosive eruptions on Earth, Mason 2004 https://www.researchgate.net/publication/227000709_The_size_and_frequency_of_the_largest_explosive_eruptions_on_Earth https://www.researchgate.net/publication/227000709_The_size_...
  • staunton 3y ago
    Volcanoes aren't about the CO2, they're about the ash which blocks out the sun and makes it colder.
  • pmayrgundter 3y ago
    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