Starker on 8/11/2016 at 19:26
Quote Posted by Vivian
I'll try and dig out the data on estimated kill-rates for the big five if you can do the same for the holocene extinction? (such a nice friendly name isn't it).
Are they really comparable for this purpose, though? After all, we are causing the sixth extinction by, for example, growing stuff that we need.
Vivian on 8/11/2016 at 19:36
Yeah. We're unambiguously causing massive problems for ourselves sooner or later. The risk (or certainty, if we're being pessimistic) of ecosystem collapse faetal is talking about is a very real one (I just don't think it will be enough to make us go extinct...). The idea that we'll still be able to grow crops at the rate we do now once pollinators start vanishing, for instance, is pretty unsupported.
faetal on 8/11/2016 at 19:49
Quote Posted by Vivian
while things are going extinct at a fucking alarming rate
right nowRight now being just the lead-up to fucking alarming stuff.
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I've not seen anything that proves it's worse than anything that's happened before? (if you've got some though please share, lazy researcher here, soz). Hence I suggested 'multiple large impactors' (which has yet to happen to a populated earth) as the kind of scenario that might make things bad enough to exterminate even an unprecedentedly cosmopolitan generalist like ourselves.
P-T data seems ot suggest that over the course of approx 200,000 years, mad sheet basalt activity raised the global average temp around 5 degrees, which led to sub-oceanic methane clathrate release causing an additional 5 degrees of warming (that's all Celsius by the way you heathen yanks) over a few thousand years, which dominoed ecosystems faster than they could adapat, killing 95% of all life on earth. Boo hoo etc... I'll at some point look into what kinds of things survived, as I reckon that is probably going to be informative, but general ecological theory stipulates that in time sof drastic flux, it is the weedy species which survive - i.e. the Japanese knotweeds of this world - cheap to make and maintain, uncomplicated and tolerant of a wide range of conditions. Daphnia and shit. Humans only really pass the third criterion.
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I also suspect we're getting a bit caught on the distinction between 'death of human civilisation as we know it' and 'extinction of humans'. It's the latter I'm talking about.
Interesting that you think the latter is such a huge jump away from the former. My argument is precisely that the former sets us up for the latter when we're out-competed by the aforementioned weedy species.
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I'll try and dig out the data on estimated kill-rates for the big five if you can do the same for the holocene extinction? (such a nice friendly name isn't it).
Always up for learning more about this - it's clearly a hobby topic for me ( I also do kid's parties etc...).
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(NB I am not poo-pooing the idea that we're as sensitive to ecosystem collapse as anything else. You are right. We are. But I am saying that we have our fingers in almost every extant ecosystem, so you would need to knock pretty much everything out to completely deny all humans, everywhere, access to something)
This assumes that post cataclysm, we'd have the same types of ecosystem, minus a few categories. Maybe that would be the case, or maybe it wouldn't. Again, depends on the extent. How different is life after the P-T extinction to that before it? Change the environment and you change the value of various adaptations. Sure we have more of them than e.g. an Anteater, but that doesn't exempt us.
Starker on 8/11/2016 at 19:52
Quote Posted by Vivian
The idea that we'll still be able to grow crops at the rate we do now once pollinators start vanishing, for instance, is pretty unsupported.
Sure, certainly not at the same rate, but isn't artificial pollination feasible at least for potatoes and the like?
faetal on 8/11/2016 at 19:53
Quote Posted by heywood
Is it?
Yes. Kind of what you'd expect if one of the life forms discovered a few hundred million years' worth of sequestered greenhouse gases and mainlined it to fuel massive expansion (which also produces different greenhouse gases).
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Ice core records, which are the best global temperature indicators we have, show a pattern of rapid +10C temperature changes which occur every 100k years to mark the end of each major glacial period. During these warming periods the rate of temperature change is on the order of what we're experiencing now. These rapid warming periods haven't produced any mass extinctions. If rapid temperature change alone is sufficiently disruptive to cause a mass extinction, there would be many more mass extinction events.
These rapid periods of warmings are returns to the mean after coolings. The difference between that and just an increase from the mean are huge.
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Although present day temperature and atmospheric CO2 levels appear to be higher than they've been in the last million years, they are still well below past maxima.
past maxima when and for how long and at which rate? Worried you may be quoting something very iffy here.
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Past maxima aren't well correlated with mass extinctions. For example, the maximum in the Eocene occurs within a period of increasing biodiversity. And the fossil record in general shows some correlation between higher temperatures and higher biodiversity. So I don't think it's a given that a hot greenhouse climate is sufficient to cause mass extinction.
Again, be careful about what you are quoting and what the absolutes are - please link source if you want a better analysis than that.
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I think #2 is all the explanation you need.
Doesn't mean it's right, though it falls into the "if it is, we'll never know" category.
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Let me add one other possibility though. The speed of light is so slow relative to cosmic distances that the time delays make two-way communication impossible. Maybe other life forms have concluded the same thing and decided not to bother.
I think that falls under the distance category, unspoken.
faetal on 8/11/2016 at 19:59
Quote Posted by Starker
I'm still not buying it. We might lose access to some knowledge, but it's not that hard to copy things by hand even if all computers stop working for some reason and we can't make any more.
When you are fighting for basic survival, what is the motivation to do so? Also, when institutions break down, there is no way of knowing how high quality the storing of information is. Is the guy an objective-minded expert you'd want curating your info, or just a stoner lab tech who is the best available option and while knowledgeable enough in e.g. cell culture, is totally clueless about electronics?
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And we, uniquely, can alter our environment in large scale. We don't just know how to grow and store our food, we know how to cultivate it and change it to our liking. We can make plants more drought resistant etc...
Yes and as someone who has worked in labs for the last god knows how long, I can tell you that it requires huge logistical stability and supplier input to maintain. It's not a briefcase and tweed jacket job.
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Now, if things got so bad that everyone would be starving to death at the same time and we even run out of soylent green, sure.
Once you get to the point where we're on Soylent Green and times get tough, how do you convinve the violent, ruthless types to resist cannibalism?
Starker on 8/11/2016 at 20:04
Quote Posted by faetal
When you are fighting for basic survival, what is the motivation to do so? Also, when institutions break down, there is no way of knowing how high quality the storing of information is. Is the guy an objective-minded expert you'd want curating your info, or just a stoner lab tech who is the best available option and while knowledgeable enough in e.g. cell culture, is totally clueless about electronics?
That would mean that everyone is constantly fighting for survival at the same time, which only applies to the doomsday scenario I mentioned above.
Quote Posted by faetal
Once you get to the point where we're on Soylent Green and times get tough, how do you convinve the violent, ruthless types to resist cannibalism?
Er... you don't? As I said, it's game over at that point. Everyone is starving to death.
Starker on 8/11/2016 at 20:10
Or are we talking about how the situation can get so bad by already assuming that the situation has gotten so bad? Assume that there is complete collapse of all civilisation and humans are barely surviving, etc?
Mr.Duck on 8/11/2016 at 21:24
Quote Posted by Starker
Now, if things got so bad that everyone would be starving to death at the same time and we even run out of soylent green, sure.
Soylent green & summer wear?
I see a themed-party coming on...
:cool:
faetal on 8/11/2016 at 21:27
Quote Posted by Starker
That would mean that everyone is constantly fighting for survival at the same time, which only applies to the doomsday scenario I mentioned above.
At the same time needn't mean within a week of each other. Over 100 years is about the same thing when you're all trending towards the same point. Again, the hypothetical scenario is what happens over 100 or so years. Seems people are focusing too much on how humans might cope immediately after a big event.
