Comments on: Are We In The Anthropocene? No. https://gregladen.com/blog/2008/01/31/are-we-in-the-anthropocene-no/ Thu, 31 Jan 2008 23:06:42 +0000 hourly 1 https://wordpress.org/?v=6.4.8 By: BrianR https://gregladen.com/blog/2008/01/31/are-we-in-the-anthropocene-no/#comment-3385 Thu, 31 Jan 2008 23:06:42 +0000 http://scienceblogs.com/gregladen/2008/01/31/are-we-in-the-anthropocene-no/#comment-3385 aahh…okay, i see what you’re saying now re Paleozoic and Pliocene … this short style of e-communication can be difficult sometimes (at least for me).I agree…boundary between the Pleistocene and Holocene has always seemed weird to me. I often have to say something like latest Pleistocene to Holocene when trying to communicate about the time since LGM.

]]> By: Greg Laden https://gregladen.com/blog/2008/01/31/are-we-in-the-anthropocene-no/#comment-3384 Thu, 31 Jan 2008 17:56:00 +0000 http://scienceblogs.com/gregladen/2008/01/31/are-we-in-the-anthropocene-no/#comment-3384 No problem, I can clarify. What I mean is this: The paleozoic has grown in length from its early conception. Also, the pliocene has gotten really short since its early conception.Well, the holocene could absolutely be an age in the Pleistocene, but more exactly, I think we should just be using the glacial stages. I think (but I could be wrong about this) that the Holocene is currently arbitrarily set at 10K, so that would not correspond to glacial stage numbering. But yes, not only would that solve the issue, but I think most people working at thousand year time scales in the late Miocene to the present (paleoanthropologists/archaeologists/glacial geologists) already think of it that way.

]]> By: BrianR https://gregladen.com/blog/2008/01/31/are-we-in-the-anthropocene-no/#comment-3383 Thu, 31 Jan 2008 17:07:36 +0000 http://scienceblogs.com/gregladen/2008/01/31/are-we-in-the-anthropocene-no/#comment-3383 Hmmm…but…you did compare the Paleozoic and the Pliocene.You said:”This has resulted, for instance, in a surprisingly long Paleozoic and a significantly shortened, even to the point of absurdity, Pliocene.”It’s entirely possible I’m misunderstanding you…I’m just asking for clarification.And, the other question was, do you think the Holocene should be an Age within the Pleistocene Epoch? Would that solve the issue?

]]> By: Greg Laden https://gregladen.com/blog/2008/01/31/are-we-in-the-anthropocene-no/#comment-3382 Thu, 31 Jan 2008 16:30:11 +0000 http://scienceblogs.com/gregladen/2008/01/31/are-we-in-the-anthropocene-no/#comment-3382 Brian,Now, you are being silly. I am not comparing the paleozoic to the pliocene. I also do not need to go on a crusade to eliminate the holocene (well, the conception of the holocene, not the actual holocene) simply because I think it is silly. There are a lot of silly things in our methods of periodization and categorization.llewelly: Yes, it is too early to tell, but I personally doubt that the glaciations are over. But maybe. The factors that probably cause the frequent and periodic emergence of glacial cycles are definitely going to go away eventually, but since they are probably mainly things like mountain ranges and the positioning of continents, that is a time scale of tens of millions of years, but the extra carbon (indeed, the existence of humans, possibly) is something on the scale of, well, much less. So maybe we’ll even skip two glaciations.

]]> By: llewelly https://gregladen.com/blog/2008/01/31/are-we-in-the-anthropocene-no/#comment-3381 Thu, 31 Jan 2008 14:55:41 +0000 http://scienceblogs.com/gregladen/2008/01/31/are-we-in-the-anthropocene-no/#comment-3381 Review this article about the ‘long tail’ of carbon emissions (by David Archer).

My model indicates that about 7% of carbon released today will still be in the atmosphere in 100,000 years

Review Pleistocene carbon levels . Archer’s findings imply that CO2 levels will remain well above any level found in the last 400kyr, for a long time – possibily long enough to melt the Greenland Ice sheet, possibly enough to melt the West Antarctic Ice sheet. Would there be another glaciation after the meltiing of one or both of those great ice sheets? I agree that it is too early to tell, but those glaciations may well be over.

]]> By: BrianR https://gregladen.com/blog/2008/01/31/are-we-in-the-anthropocene-no/#comment-3380 Thu, 31 Jan 2008 14:12:34 +0000 http://scienceblogs.com/gregladen/2008/01/31/are-we-in-the-anthropocene-no/#comment-3380 You say: “I can say with confidence that most people in the biz recognize that the Holocene is silly. You’re just not there yet.”So your argument is that the Holocene is “silly” but you don’t want to get rid of it? Do you want to call it something else? Or, we just recognize it and not do anything about it? I’m sorry if I’m “not there” yet, but as someone who works on both ancient and recent geologic problems, I find the Holocene division very useful. I guess I don’t understand your beef with the Holocene. Would you rather it be an Age of the Pleistocene Epoch? If so, then work towards changing it…simply complaining about silliness won’t change what you think is silly.You say: “…we have an increasing resolution, and in fact a fairly even resolution at the level of major transitions, of earlier times.”What do you mean “increasing”? Because we are learning more? Which earlier times? Into the Proterozoic? I disagree…we don’t have even resolution at all. But, perhaps i’m simply misunderstanding you.You say: “This has resulted, for instance, in a surprisingly long Paleozoic and a significantly shortened, even to the point of absurdity, Pliocene.”But, the Paleozoic is an Eon and the Pliocene is an Epoch … they are two divisions apart on the hierarchy (with Period in between). I don’t think it’s fair to compare them like you have in that statement.Perhaps I’m being nit-picky, but this is what scientists do…don’t read it as combative 🙂

]]> By: Greg Laden https://gregladen.com/blog/2008/01/31/are-we-in-the-anthropocene-no/#comment-3379 Thu, 31 Jan 2008 13:50:32 +0000 http://scienceblogs.com/gregladen/2008/01/31/are-we-in-the-anthropocene-no/#comment-3379 Brian,You’ve assaulted my argument on the basis of length. Put that aside for a moment. The Pleistocene is a period of glacials and interglacials. We are in an interglaical of the Pleistocene. That is my main argument, and as a person who works in the middle-upper Pleistocene and Holocene, I can say with confidence that most people in the biz recognize that the Holocene is silly. You’re just not there yet.But, even if one wanted to consider length, the situation is the opposite of what you are indicating. I’ve not been precise in my use of terminology, but I’d better start now to make this clear. The major periods have varied in estimated length not because we have more resolution of the more recent times, but because we have an increasing resolution, and in fact a fairly even resolution at the level of major transitions, of earlier times. This has resulted, for instance, in a surprisingly long Paleozoic and a significantly shortened, even to the point of absurdity, Pliocene. And don’t even talk about the Villafrancan and what happened to that.Retaining the Holocene is convenient, and I have not actually proposed that we dump it. I merely propose that we see it for what it is … utterly silly. It exists by a definition that is utterly different than anything we use to define either the beginning of the Pleistocene or the sub divisions of the Pleistocene. It’s like telling people who live in unit 14B of a large apartment building that they live in a different house and expecting them to believe it!I totally agree, though, with the part of your comment where you totally agree with me.

]]> By: BrianR https://gregladen.com/blog/2008/01/31/are-we-in-the-anthropocene-no/#comment-3378 Thu, 31 Jan 2008 10:44:26 +0000 http://scienceblogs.com/gregladen/2008/01/31/are-we-in-the-anthropocene-no/#comment-3378 you say: “and the Holocene is not scientifically valid”Why? Just because it’s just an interglacial? Doesn’t matter. Look at the geologic time scale and all the divisions we break out have shorter durations the closer to the present. This is because we have better chronologic resolution, more context of paleo-conditions…basically, more information. I don’t think it’s a problem at all. For those doing Quaternary geology, it is extremely valuable to break out the time period since de-glaciation. We know way more about the current interglacial than any of the others. The time periods are NOT defined by how long they are. They are a function of resolution. The Holocene is 11 kyr, the Pleistocene is ~2 my, the Pliocene is ~4 myr, the Miocene is >15 myr, and so on. And they are all Epochs. Are those all scientifically invalid?You say: “But those proposing the Anthropocene are several million years premature. They need to be more patient.”Why several million years? Why is that the magic number? The Eocene Epoch is ~20 my long … should we wait that long?The boundaries for the distinct time divisions we’ve broken out are based on big changes in the record of the Earth’s history. It’s NOT based on how long they are.Like any historian, those that study Earth history have more information in the most recent time…I think it is not only valid but helpful to further subdivide if you have more information. We discuss the history of human civilization a few thousand years ago by century, but we break out the 20th century into smaller bits, essentially by decades. Is this invalid?The Holocene is perfectly valid…your argument for why it is invalid doesn’t hold up. Now, whether or not the last couple hundred years of changes deserves their own time division is another issue. I’m not completely sold on that just yet.

]]> By: Ahcuah https://gregladen.com/blog/2008/01/31/are-we-in-the-anthropocene-no/#comment-3377 Thu, 31 Jan 2008 10:01:11 +0000 http://scienceblogs.com/gregladen/2008/01/31/are-we-in-the-anthropocene-no/#comment-3377 I think you are right on with the “Anthropogenic Extinction” distinction.If the Anthropocene folks were consistent, they would also demand that we rename the Paleocene the “Chicxulubene”. (Or maybe the “Deccantrapsene”.)

]]> By: Ian https://gregladen.com/blog/2008/01/31/are-we-in-the-anthropocene-no/#comment-3376 Thu, 31 Jan 2008 09:49:43 +0000 http://scienceblogs.com/gregladen/2008/01/31/are-we-in-the-anthropocene-no/#comment-3376 Forget the Anthropocene – when does the Obscene start?!!

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