5 ms·

It is a bit syrreal to read about low probability/high impact risks while we have a very high probability/catastrophic impact event already started.

• jefftk 6y ago
  What catastrophic impact event are you referring to? Covid-19? Climate change? Neither of those are existential risks: they're incredibly unlikely to wipe us out. The kind of high impact risks the article is about are much worse.
  • chickenpotpie 6y ago
    Uhhh, climate change will absolutely kill us all if we don't do something.
    • apsec112 6y ago
      No climate forecast that I'm aware of predicts human extinction; much of Earth would still be habitable by humans even at +20 C (although that would trigger a huge mass extinction among other species). There's a big gap between "pretty bad" and "literally no survivors".
      • stevens32 6y ago
        20c being habitable seems like a stretch to me, and my Google Fu only turned up mentions of Antarctica hitting 20c. Have any references for that number? Most reports I've read say a +2c will cause significant problems globally.
      • CraigJPerry 6y ago
        +2c would make plenty of inhabited areas uninhabitable, ive never seen predictions of +20c, what would that even look like? The crop failures and localised starvation of +2c would become global at +20c. The migration of people, something that humans are historically absolutely terrible at handling, would be on an unimaginable level. Imagine the bloodshed.
      • oska 6y ago
        The risks involved with rapidly changing the planet's climate are huge and largely unknowable. We're running a very dangerous experiment where we can't know what all the results will be. Hence, you don't run the experiment.
      • cmehdy 6y ago
        Europe has struggled "pretty badly" with migrant crisis on the order of a few million people. Fairly soon, estimated climate change refugees in one of the most prosperous and advanced areas of the world is going to be at one order of magnitude more[0], i.e. about 1 person in 10 in Europe will have been fleeing death. This isn't +20C, this is within the next few decades. At the scale of the world, we're talking about predictions of 150 million refugees by 2050[1]. Sea level rise is one thing, but climate change is also desertification, tornadoes, death of the seabed[2], melting glaciers and re-arranging of maritime currents therefore weather patterns. The decline of structures of agriculture can also lead to radicalization of people in some areas of the world (see [1] again). The collapse of food chains can also be global, and just for the US alone for example a rise of 4 degrees would cut corn production in half[3], while precipitating what is already in motion (again, just for the US as an example, migrant crises from Central and South America[3]). Uprooting not only entire industries but entire cities, states, and lives on an order of magnitude significant for any major country of union in the world, is not something that will be easily done without significant loss of quality of life, rise in tensions and potential wars, and widespread shortages of resources. I imagine your reference to +20C is wildly exaggerated, because there is so little research about that since predictions about compound effects become exponentially more difficult. Even just an estimate that's over a decade old of up to +5C change already presents risks to India, China, ocean life, and major cities like NYC, London and Tokyo[4]. At +3C in the world, due to differences between land and sea it is possible that on average people (who are on land) would experience rises of averages closer to +7C already.[5] Needless to say that +20C is something else entirely, and it's likely that no possible study would do justice to the idea due to catastrophic cascades of effects. The claim that humanity would still be inhabiting Earth would probably require some redefinition of "humanity" and "inhabiting" if survival/adaptation proved to be possible, which are all far-reaching thought experiments with the extent of current knowledge. [0] https://helprefugees.org/news/climate-change-refugee-crisis/ https://helprefugees.org/news/climate-change-refugee-crisis/ [1] https://www.brookings.edu/research/the-climate-crisis-migration-and-refugees/ https://www.brookings.edu/research/the-climate-crisis-migrat... [2] https://phys.org/news/2018-04-climate-ocean-food-chains-fish.html https://phys.org/news/2018-04-climate-ocean-food-chains-fish... [3] https://www.theguardian.com/commentisfree/2019/apr/06/us-mexico-immigration-climate-change-migration https://www.theguardian.com/commentisfree/2019/apr/06/us-mex... [4] https://www.newscientist.com/article/dn11089-the-impacts-of-rising-global-temperatures/ https://www.newscientist.com/article/dn11089-the-impacts-of-... [5] https://www.bbc.com/news/science-environment-52543589 https://www.bbc.com/news/science-environment-52543589
      • analbumcover 6y ago
        +20C global average warming would correspond to roughly +40C land average warming. With polar regions seeing significantly more warming, at least +60C. That would see the coast of Antarctica averaging Death Valley's summer highs. Suffice to say, humans are not going to survive +20C global average warming.
    • RandallBrown 6y ago
      How would it kill us all? I suppose it could lead to a Venus like atmosphere if things got really crazy. Realistically the worst case scenario would just lead to coastal areas being uninhabitable and widespread famine and unrest while the worlds farming and population gets redistributed to more habitable latitudes. I don't think it would ever wipe out EVERYONE even if it's a sizable percentage.
      • jbay808 6y ago
        I agree with you. But you don't have to go quite all the way to Venus for a plausible scenario that would, probably, wipe out humanity. See page 6 of this link for a scary infographic. http://burro.case.edu/Academics/USNA229/impactfromthedeep.pdf http://burro.case.edu/Academics/USNA229/impactfromthedeep.pd... Of course direct emissions won't get there alone, but runaway feedbacks could.
      • infogulch 6y ago
        There is no "redistribution to more habitable latitudes" (a breathtakingly vast understatement of human suffering) without all out war. There is no all out war without nuclear destruction at our own hand.
      • justin66 6y ago
        Intuitively it seems very difficult to see how things could go all the way towards being Venus-like if all the positive feedback mechanisms kick off. We're really, really similar to Venus, but Earth's crust wouldn't appear to have that many greenhouse chemicals stored up. (Unless geologists have failed to account for something) But there's a long distance between Venusian hellscape (hot enough to melt lead and raining sulfuric acid) and what we have today, and most of it is pretty awful for us. "Kill everybody" isn't crazy.
      • titzer 6y ago
        If your plan involves moving the entirety of food production to areas of the globe that are currently permafrost and have no comparable ecosystems to where we are currently farming, you are going to have a bad time. You can't just bootstrap a healthy, thriving set of soil conditions, food webs, etc in a couple years. These things normally take thousands or even tens of thousands of years on geological timescales. Just look at how long it takes deciduous forests to reach their apex state: thousands of years.
    • nicc 6y ago
      Uhhhh, no.
  • adrianN 6y ago
    There is almost no event that will wipe out humanity with certainty. Our species could survive for millennia in hermetically sealed caves, huddled around underground breeder reactors. There is however a very real risk of wiping out our current way of life; civilization is quite brittle. That would of course mean that we no longer have the means to sustain eight billion people, and most of them would die. The latter is what most people refer to when they say that climate change is an existential risk, because there is a very real danger that our population drops massively over the next hundred years or so. And not because we finally figured out how to use contraceptives.
    • wizzwizz4 6y ago
      0.05c 2km asteroid. Grey goo. Fast UFAI takeoff (e.g. paperclip maximiser). Nuclear holocaust damaging our infrastructure enough that we don't survive the next big asteroid (speaking of which, we have no anti-asteroid infrastructure). Bioweapons causing widespread infertility, airdropped over uncontacted tribes.
    • tuatoru 6y ago
      > danger that our population drops massively over the next hundred years or so. And not because we finally figured out how to use contraceptives. According to the evidence from Brazil and India, because we watch TV. According to the evidence from China, because of access to basic healthcare[1]. (I don't know of any evidence about video games, but they'd contribute too.) [1] China's "one child policy" is blamed for the drop in fertility there, but if you look at the charts, fertility started trending down with the "barefoot doctor" campaign (someone with basic hygiene knowledge in every village). The one child policy coincides with a slight pause in the decline.