Global Anoxia Ruled Out As Main Culprit In the P-T Extinction 158
Garin writes "The late Permian saw the greatest mass extinction event of all-time. The causes for this extinction are hotly debated, but one key piece of the puzzle has recently been revealed: while the deep-water environments were anoxic, shallower waters showed clear signs of being oxygenated. This rules out global anoxia, and strongly suggests that other factors, such as the Siberian Traps vulcanism, must have played a dominant role. From the article: 'Rather than the direct cause of global extinction, anoxia may be more a contributing factor along with numerous other impacts associated with Siberian Traps eruption and other perturbations to the Earth system.' See the full research article (behind a paywall) here."
Siberian Traps (Score:1, Funny)
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We aren't all named Snowden
Re:Siberian Traps (Score:5, Informative)
The meteorite in the Yucatan was at the end of the Cretaceous period, they are referring to a proposed impact over 400 million years earlier due to some discoveries of a potential 300 mile wide impact crater in Antarctica... The Cretaceous extinction even only killed off about 75% of species as compared to 90% being killed off in the extinction that this article is about.
Apparently, the super volcano in this case erupted for nearly a million years, warmed the oceans to 100 degrees F and forced all organic growth (as measured by coal deposits) to the poles. Whether caused by an impact or mantle event, it would be incredibly destructive to any 'society' living on the planet
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The end-Permian mass extinction was at around 252 Myr ago ; 190 Myr before the end-Cretaceous mass extinc
Global Anoxia? (Score:2, Troll)
Just eat a sammich, Girl!
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Not agreed at all, within the professional geological community (Discovery Channel producers may disagree, but they'll come round to our point of view, once we decide what that is). For a start, it may have been up to 300,000 years before the end-Cretaceous mass extinction (though that is still a matter of disagreement).
ITYM "Tunguska" ; the hypocentre was near the "Stony Tunguska" river.
The geological evidence does n
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They are passing for babushkas.
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Speaking as a man married to a Russian woman, I can assure you that cross Russian un-dressers can be positively mesmerising. And "demanding" in a way that will get the average Slashdot denizen rubbing the hair off the palm of his hand just thinking about it.
A Breathtaking Report!! (Score:5, Funny)
or not...
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Well WTH, I have to pass half the terms in the summary through Wikipedia to figure out what the heck they're talking about? This is supposed to be a self-selecting site for smart folk, but being smart in one area doesn't make you knowledgeable in another.
It would probably help if the editors required more than just copypasta from the original article. I don't think I'm being dumb, just acknowledging that I'm ignorant of certain topics.
Re:A Breathtaking Report!! (Score:5, Informative)
Well, ok. Though there's not much more that I could have written in that short of a space that can teach the subject.
I linked the Calgary Herald / Postmedia News article because it's an astonishingly well-written bit of science journalism that lays it all out superbly – kudos to Randy Boswell. He didn't put *exactly* the same emphasis on exactly the same things that Proemse (the principal author) would have, but it's minor. That's the "public" piece, and it's full of tons of great information.
I also linked the official research article. Unfortunately it's behind a paywall. However, if that's the kind of thing that really turns your crank you probably already have access to it one way or another (in the worst case: via a physical trip to your local university). If you can't, well, correspondence with an author is a time-honored method for obtaining your own copy.
Re:A Breathtaking Report!! (Score:4, Informative)
Actually, I'll take that back about the emphasis bit. Boswell pretty well nails it right on the head. Now I'm looking through some of his other articles, and they're excellent.
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The issue is that no crater has been found in an antipode position to the Siberian traps. However, there is a theory that the Wilkws Land crater, underneath the Antarctic, is 250 myr old, and would match the location of this crater.
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While I don't accept any of your other stuff without checking (and I'm pretty dubious of it's relevance in any case), this is relatively easy to dispose of.
Unless I've misunderstood it substantially, van Westrenan is talking about accumulating fissile deposits at the core-mantle boundary. That's just shy of 3000km below the surface.
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You are doing more than acknowledging said ignorance: you are implying that other people, rather than you, should take some action about this. You are not being dumb, you are being lazy and entitled, which is much worse.
Also, if the summary truly was incomprehensible to you, your level of general knowledge is rather pathetic. Not that that's surprising with that attitude.
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More like someone forgot their education. And then decided to make drama out of it.
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Well WTH, I have to pass half the terms in the summary through Wikipedia to figure out what the heck they're talking about?
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Re:A Breathtaking Report!! (Score:4, Funny)
or not...
It turns out that the reports of anoxia in the Permian were actually full of hot air.
Damn Vulcans! (Score:4, Funny)
Re:Damn Vulcans! (Score:5, Funny)
Over-zealous potty training can be lethal.
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Spock dropped out of graduate school to join Starfleet and never completed his Ph.D. Therefore it is illogical to call him Dr.
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This is relatively good news. (Score:5, Insightful)
Given that we show every sign of running the CO2-enhancement experiment to completion, it is reassuring to know that this low-probability but extremely-high-cost outcome is that much more unlikely. (To my warmist comrades -- given a choice between losing a toe, a leg, or a life, we know which choice we would most want to avoid, but that does not mean the remaining choices are good. Anoxia is among the worst of the outcomes, far worse than the middle of the US becoming uninhabitable or the seas rising 100 feet. And to you denier bozos -- greenhouse science is cut-and-dried stuff, with only the detailed outcomes unclear, but it's also clear that between natural human greed and your foolish efforts, we will almost certainly burn all the fossil fuels we can until something truly alarming occurs. Perhaps we have overestimated the effects of the current CO2 levels -- but that's okay, we're just going to keep on burning it till we see an effect, and a big and unambiguous one.)
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we're just going to keep on burning it till we see an effect, and a big and unambiguous one.
No, we're seeing effects already. We're going to keep burning it until the devil is knocking at the door, then the skeptics will be the ones screaming the loudest about how they're new solution is the best.
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We're going to burn until we run out of fuel. If we get some disaster before that, we'll just burn more fuel to cope with it (what'll probably involve shooting people and throwing bombs around) untill we have no other option available.
Global Warming is not the kind of disaster humans can deal with.
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Anoxia was never a possibility. The majority of fossil reserves is unexploitable. Even if we cut down all forests and burned everything we found, there's way too much oxygen in the air for it to make a difference.
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It's not a simple use-all-oxygen-burning-fuel anoxia -- it is a bad interaction with ocean circulation, chemistry, and biology: http://en.wikipedia.org/wiki/Anoxic_event [wikipedia.org] .
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I read anoxia as anorexia.
ditto!
OTOH, I can how falling for traps would lead to extinction.
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I read anoxia as anorexia.
At least you didn't read it as dyslexia.
Re:Anoxia misread (Score:5, Funny)
I read anoxia as anorexia.
90% of all species died... but they were looking very stylish right up to that point...
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I read it as anxiety. Should I worry about that?
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Maybe by the time we are done with this planet, P-T will look like a cakewalk in comparison.
Well, our "mass extinction" has already resulted in a global, industrial society so it's well ahead of the P-T extinction already.
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Ants.
They don't have societies beyond the scale of limited cooperation between nests. Bird migration would be at least on the right spatial scale.
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A good point, and one that I was considering raising myself.
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Once all the carbon is released, the globe will be roughly where it was during the Eocene. That means: lush vegetation, lots of mammals and primates, forests in the Antarctic and Sahara, far less temperature differences between high and low latitudes, and generally a warmer and wetter climate.
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That's true. Provided you can move a few continents to where they were back then, else it might be a wee bit different in the outcome.
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The continents weren't in hugely different positions. Ocean currents have changed somewhat. But on the whole, there is no evidence that Eocene-like CO2 concentrations would result in very different effects now than they did during the Eocene. They would certainly not result in "anoxia".
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It's rather doubtful indeed. Still, I kinda doubt it will be a pleasant life.
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For the last few million years, we have had severe glacial periods every 100000 years and brief interglacials. That kind of harsh climate may have forced the evolution of H. sapiens, but by any objective standard, it is "not pleasant". Without AGW, we'd probably be starting another deep glaciation within a couple of thousand years. Human carbon emissions may be putting that off, and I don't see why that's a bad thing.
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And indeed, that current levels of biodiversity will be maintained - that global warming will not result in the loss of bio-diversity?
You have a model that discounts the 20% hit to global GDP evident in other published works?
Whereabouts might we find your model - I assume it's been published?
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And indeed, that current levels of biodiversity will be maintained - that global warming will not result in the loss of bio-diversity?
Human involvement has already destroyed a vast portion of Holocene biodiversity even without the global warming, and will continue to do so for quite some while. Even if the biosphere were completely immune to temperature changes, how's this trend supposed to reverse? (We can't clone most of the species we've destroyed.)
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If we had to we could fix that. Fallout would be ugly, but the Darian gap anarchy/FARC base issue would be solved.
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Comparing the Eocene with modern AGW is like comparing parking your car at the mall with crashing your car into a tree: They both involved trips where the car reduced its speed from 60 to 0 MPH.
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Do you have any more such stupid and unscientific analogies?
Evolution Too Slow For AGW: (Score:2)
"Many vertebrate species would have to evolve about 10,000 times faster than they have in the past to adapt to the rapid climate change expected in the next 100 years, a study led by a University of Arizona ecologist has found." [uanews.org]
The rate of change we are facing could put more than half of all species in danger of extinction. And because this rate of change is so unnaturally fast (unprecedented), this assessment is more than likely "conservative" (i.e. erring on the side of irresponsibility so as not to appe
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There are lots of things wrong with that analysis. It assumes that species only adapt to climate change by evolution, but they can adapt by migration. It confuses global mean temperature changes with local changes. And the rate of evolution is not fixed, it is driven by environmental change: more change means a faster rate of evolution. In fact, extinctions are a primary driver of evolution. In addition, for millions of years now, every 100000 years, global mean temperatures change by about 3-4C in a few th
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You didn't read/comprehend the article, and you have no concrete data to support your position.
In any case, we do have new technologies to deal with the problem but any expectations they (would have to) fit comfortably into the old industrial-consumer framework is misguided.
Ah, the old 'allow industry to keep doing its
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No, I'm afraid you didn't comprehend the article and lack the background to interpret it.
You apparently don't even understand scientific writing: "Despite many caveats, our results suggest that adaptation to projected changes in the next 100 years would require rates that are largely unprecedented based on observed rates among vertebrate species." The phrasing "despite many caveats, our results suggest" doesn't me
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Well that's an interesting interpretation, from a person who confuses inter-glacial temperature change over many millennia with a similar number of degrees toward a global hothouse over a few hundred years.
'Caveats' likely means possibly-mitigating factors that they considered but which didn't negate their hypothesis. I have never seen the
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The relevant phrase here isn't "caveats", the relevant phrase is "suggests". I'm sorry, but you're obviously too scientifically illiterate to even discuss this any further.
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The relevant phrase here isn't "caveats", the relevant phrase is "suggests". I'm sorry, but you're obviously too scientifically illiterate to even discuss this any further.
You should take a look in the mirror when making that accusation. A great many (if not most) scientific papers use just that term to claim that the data supports their theory.
Trolling for the denier position that complete certainty is required before an idea can be considered credible... That is not how science works, and I think its telling how you're been arguing here without references.
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Indeed, a great many scientific papers use the phrase. And they deliberately use "suggest" instead of "prove", "disprove" or "support" when the data isn't good enough to use those stronger phrases. "Suggests" is little more than the author's opinion.
The way science works is through many repeated exp
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And you missed the other studies I linked to, apparently.
That is still one of the recognized denier tactics (the label is especially apt when arguing from a "scientific", hence "informed", viewpoint). The consensus is farther along than you will admit because you largely ignore/reject ecology.
It is your camp of buffoons that must prove the economic status quo is more deserving of
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Actually, they do support the first study. Now, you were saying something about " We accept scientific theories only if they have stood numerous attempts at falsification"..? I know you didn't bother reading them, but they all support the idea that rapid climate change leads to high rates of extinction.
For that matter, AGW reasearch (on temperature) hasn't stated tha
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"Global warming activists" is an identity that many identify with. "Deniers" is a fictitious foe and straw man created by global warming activists.
A lot of the references weren't scientific papers. The ones that were did
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Those references had scientific papers behind them, and the one you are attacking you didn't even read (which means you read none, IMO). The methods you are using to attack are rhetorical, twisting a word like "supports" (or lack of a word like "proven") into an accusation of unexamined assumptions. You also misappropriate terminology from climatology to give your rhetoric an air of credibility.
Tell that to your grandchildren. C
Re:Gasping (Score:5, Insightful)
And this is why people laugh at Deniers as they have no idea of the science or the problem.
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How does "Once all trapped CO2 will be released" [in the future] equate to "400 PPM" which we have already past.
Perhaps your reading skills need a polish.
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and btw, i am not suggesting we will all die of Anoxia but people who say "The Earth's climate was warmer before than now as little as 12,000 years ago" clearly are not following the science and are just spouting denier rubbish.
Re:Gasping (Score:5, Informative)
Sure, read Skeptical Science [skepticalscience.com]. Those quoted figures are from one single location and may not reflect what was happening elsewhere. This site is an excellent example of good science and they have extensive responses to the common denier arguments. I would recommend spending some time there.
Also, keep in mind that the issue is what is forcing the increase. The 400PPM is not going away in our lifetime nor our grandchildren's lifetime. This problem will get worse not better. And of course 12,000 years ago the population was a lot smaller. The total world population probably never exceeded 15 million inhabitants before the invention of agriculture [wikipedia.org] so with 7 Billion people alive today the impact of a warmer environment is likely to be higher than it was 12,000 years ago.
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This problem will get worse not better.
The assumption here is that the current state is a "problem" and that getting warmer than this is "worse". These are two assertions I would dispute. Have you some evidence to support these two claims?
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That is a fair question and the answer is not completely known. But the indications are not great [skepticalscience.com]. I can turn this around, why are you confident that all will be fine?
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The current state is obviously a problem because we already know it's driving weather which we find inconvenient.
We know that getting warmer than this will be a problem because it leads to more of the same.
Evidence to support these claims? Are you fucking serious? That's all that this science does.
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I did not assert that all will be fine. Why do you put that on me when I did not say it? Are you seeking some consensus with me?
I would assert that a return to ice age conditions is not desirable. On this I hope we can agree. In this we can set the outer bound of acceptable conditions on the colder end to -0.8c below 20th century norms because any lower than that and glacial forcings push the average temp down to -8c rather abruptly. That evolution is suboptimal for agriculture and animal husbandry, a
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Certainly at +6C vast swaths of terrain in Russia and Canada are opened for agriculture, but is that good? I don't know.
Plants need light as least as much as they need warmth.
And vast swaths of terrain in Russia and Canada have very poor light levels during large amounts of the year.
Maybe lettuce and other greens can be grown a 2nd season. Perhaps moss salad will become haute cuisine.
But don't overlook the fact that a lot of the water to irrigate current agriculture comes from snow pack that melts all summer long... So - warmer weather = less snow pack / faster melt might just mean less agricultural productivity. Subterra
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For mankind, if you give a rat's ass about that miserable apex predator, perhaps not so much. At 7+ billion annoying human beings (that number must give some marketing people prolonged orgasms) we're crammed up at the edge of carrying capacity of the environment. So it's not going to take much more change to get some (billions) of people in significant trouble.
Climate happens to be well down the list of things that are going to cause trouble here. Poverty, overpopulation, and a lot of poor practices that are far more destructive than emitting carbon dioxide (such as corruption, pollution, poor water management and farming practices).
This bothers a lot of tender souls, especially those persons who wonder what happens when large swaths of the equatorial band on the planet become less habitable. You know, that large band where 70% of the planet's human infestation resides. That group of people who might resent being starved and dehydrated to death. Some of those people have heard of the aphorism 'the veneer of civilization is thin, indeed' and wonders what happens when the coating gets scraped off.
There probably would be a die-off. I don't see addressing the alleged harm of global warming helping prevent that situation. Too much prosperity is dependent on the use of fossil fuels right now. And for all the talk, the alleged prob
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In this we can set the outer bound of acceptable conditions
Symbolset, are you saying that somehow we can control the increase in temperature? that we can just stop it when it is acceptable? If so, you truly do not understand the situation we are in. CO2 in the upper atmosphere is the problem and this is long living, possibly for hundreds of years or longer. We are deep doo-doo and not recognising the true extant of the problem is not helping.
vast swaths of terrain in Russia and Canada are opened for agriculture, but is that good? I don't know.
This is straight out of the denier playbook and just confirms you are out of touch with the problem. btw, one note, most p
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What they don't see, and wouldn't care even if they could, is that _change_ means we move our crops to where they will grow best. That means the current agribiz folks lose more money than they would addressing global warming but that loss is decades in the future whereas any current loss due to co2 markets would show up on next quarter's balance sheet.
We need to cost out that exte
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How does "Once all trapped CO2 will be released" [in the future] equate to "400 PPM" which we have already past.
How can we release all trapped CO2? Most of it is locked in stone - limestone. As I recall, toxicity problems start appearing around 5,000 ppm which is still a bit away, especially if plant life starts hovering up that excess CO2.
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Plants hovering up the CO2 is a common Denier Myth [skepticalscience.com]. Do you have cites for how that works?
And do we need to release 100% of CO2 before it is a problem? Or are you just trying to spin the argument?
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Plants hovering up the CO2 is a common Denier Myth. Do you have cites for how that works?
Well, we wouldn't have an oxygen-rich atmosphere in the first place, if plants weren't hovering CO2. Second, it takes work to separate CO2 from atmosphere. As the concentration of CO2 increases, plants use less work to extract and use CO2.
As to your link, I find it interesting how much effort is wasted on making up evidence that elevated CO2 levels are bad for plants. For example, a lot of effort goes into claiming that CO2 can damage plants (linking to a study on the Paleoceneâ"Eocene Thermal Maxim
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thanks for the link. i will read it fully later on. btw, note some of the items in it....
> Over 10,000 years temperatures rose by as much as 8C
So 10,000 years for an increase gives a lot more time for adaption. Our temperature increases could be over a much shorter period
> lasted for around 100,000 years before the additional CO2 was gradually re-absorbed into natural sinks and temperatures fell back to their original levels.
So, the turnover time for the "natural sinks" to reabsorb the CO2 is a very
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So 10,000 years for an increase gives a lot more time for adaption. Our temperature increases could be over a much shorter period
Or it might never even come close. There's too much speculation and not enough fact.
So, the turnover time for the "natural sinks" to reabsorb the CO2 is a very long time
Or carbon dioxide content didn't drive the end of the period. But as I remarked, that is evidence that plant growth does in natural environments increase in the presence of higher levels of carbon dioxide.
The point being that it is not simply the case that we don't need to worry about it as the plants will just take up the CO2. They eventually will but not before mass-extinction of species.
So what? My take is that there will that mass extinction of species not matter if there is substantial global warming or not due to habitat destruction and possibly social breakdown during human die-offs.
Also keep in mind how disruptive this would be given the human population, stressed food supplies (eg fish), political issues of mass migration of people etc.
There's no evidence
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> And they'll do it without killing too many people
Gee i feel better already
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No i didn't post it. You did. You are confused about that?
No i am not a charlatan planning to reap profits from fear and uncertainty. Why, are you giving lessons?
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Well sounds like you are jumping at shadows. I am all for focusing on the science. So i take it from this that all your other responses are just trolls. Back under the bridge with you!
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Oh, don't worry. Humanity will survive. Unless we kill each other in the attempt to stay dry.
The main reason why this wasn't a big deal about 12,000 years ago is simply that there was plenty of room and very little in terms of population. Moving inland when your coastal area was being flooded wasn't that big a deal (not to mention that the gods were to blame for it and who could argue that people have to move when their gods tell them to?).
It just MIGHT be a bit different today when I really don't feel like
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Re:Gasping (Score:5, Insightful)
Well, some people do care whether other people can survive. The point is simple: People will want to survive. If necessary, by floating on your corpse.
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Hope you have no problem moving your house accordingly. Or finding someone dumb enough to buy that beach estate.
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Well, that's also a position to take, but the problem is that people who built their houses there for whatever dumb reason won't simply go "oh well, I was dumb, here I sink, farewell dear world".
They'll come to YOU and want YOUR home. Whether they get it and kick you out or die trying doesn't really matter much, considering that they have no real option.
And somehow I don't feel like fighting someone who cannot back down.
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"oh well, I was dumb, here I sink, farewell dear world".
Oh well, I was dumb, my house sank. Got my insurance check. Gonna rebuild inland a few miles.
Why do you think they would go down with the "ship" so to speak?
They'll come to YOU and want YOUR home. Whether they get it and kick you out or die trying doesn't really matter much, considering that they have no real option.
What on Earth.. do you really think that way? You lose your house so you feel entitled to kill others??
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If it's down to "you survive or I survive", what matters is who holds the gun.
The problem is then that there are more people than there is room for. It's already pretty crowded in most of Europe (I admit, it's less so in the US), but even then it's unpleasant because those insurance companies will not sit on the loss, they'll want their money back. Take a wild guess who gets to pay.
Not to mention that it's almost certain that the government will pump a few millions towards the coast as "aid". Your tax money
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Better double-check that policy. For years I've been advising anyone I meet in the insurance game to remove those elements of cover. They may have gone one clause at a time over several revisions, or just been dropped completely for new customers. But it's essential for insurance companies to drop those unavoidable costs as soon as possible. Insurance is about playing the probabilities ; if the probability of a payout approaches 1.0, then the annual
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"Tough."
Buying it was your decision. Selling it is your problem. If you'd asked me for my opinion (paid for, of course), then I'd have advised you to not do it if you expected it to be worth anything at all in 50 years time, but even then, I'm not going to take responsibility for you not following my advice.
Incidentally, if talking like this harms the resale value of your beach property, once more I say "tough."
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If you can get two extra meters of elevation you should be good for a human lifespan.
The sea has risen nine feet in the last hundred years and is projected to rise nine feet in the next fifty. But ice melt rate is exceeding all propositions. Even if it weren't, though, you'd still be wrong.
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Umm no it hasn't.
http://en.wikipedia.org/wiki/Current_sea_level_rise [wikipedia.org]
The longest running sea-level measurements are recorded at Amsterdam, in the Netherlands—part of which (about 25%) lies beneath sea level, beginning in 1700.[44] Since 1850, the rise averaged 1.5 mm/year.
Since when does 1.5mm X 163 = 9 feet
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While not agreeing with symbolset's denialist position, I do agree with him on this point.
I've thought carefully about where to invest in property ; regarding people who haven't invested that degree of thought have made a mistake : "Just Think Of It As Evolution In Action."
(And for irony, I'm not even playing the evolutionary game for the rest of the gene pool of Homo sapiens.)
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he Earth's climate was warmer before than now as little as 12,000 years ago.
No, it wasn't. 12,000 years ago was just after the end of the last glacial.
Before that it was mostly uninhabitable by humans for 100,000 years except for some equatorial regions because: ice.
No, it wan't. Glacials certainly don't make "non-equatorial regions" uninhabitable. At the height of the last one, most of the US and more than half of Europe were certainly inhabitable.
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First: you might have logged in for this post and given it your cred, even if it was your first post.
Children asphyxiating at 400 ppm CO2 is completely unrealistic. It is hyperbole. It is absurd. At 40,000 ppm it might become credible, but 40K ppm is not plausible if we cooked off every potential fossil fuel including methane clathrates, every bit of limestone and every bit of granite on the surface of the Earth two miles down. It's not going to happen unless the kid is asthmatic, and then pollen or mol
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It's actually plausible at around 2,000 to 4,000 ppm CO2, more likely at 5,000 to 10,000 ppm, 30,000 ppm will kill you. (5,000 ppm is OSHA's [osha.gov] 8-hour TWA limit, some people feel symptoms at lower exposures) It's not the lack of oxygen that would be the issue, it's the body's respiratory/metabolic feed