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Has anyone read the full version of this paper?
"Stomatal proxy record of CO2 concentrations from the last termination suggests an important role for CO2 at climate change transitions"
This paper contains an interesting and rather unexpected result. I have only seen the abstract, has anyone read the full paper? It raises all sorts of questions. What do you make of it?
This is a quote from a review...
' A new paper published in Quaternary Science Reviews reconstructs CO2 levels during the termination of the last ice age and finds CO2 spiked to levels near or even exceeding those of the present, obviously without any human influence. According to the authors, "The record clearly demonstrates that [CO2 levels were] significantly higher than usually reported for the Last [Glacial] Termination," with levels of up to ~425 ppm about 12,750 years ago, which exceeds the present CO2 concentration of 395 ppm. '
http://ars.els-cdn.com/content/image/1-s2.0-S02773...
12,750 years ago would place this during the Younger Dryas cold event. So where did the CO2 come from?
Dear Dookie. " but I did read the title and the abstract, neither of which you quote." I gave you the title of the paper immediately following the title of this question. It's the sentence in quotes. I also gave the link to the abstract. Re your comment "Had you bothered to read even those few sentences"... I did bother thank you, and this raised some interesting questions that I thought someone knowledgable here may be able to offer some insight into. That person is clearly not you.
The paper I'm asking about has nothing whatsoever to do with the Marcott paper. I am at a loss to understand why you linked it.
Comprehension 0/10. Try to keep up.
The interpretation of the question "framing" is entirely yours. Here are the thoughts that immediately came to mind when I read the abstract and review that prompted me to ask this question.
I was surprised to see a proxy record show 425ppm atmospheric co2 in a climate system that was comparable with
ours. Usually higher concentrations are only clearly evident in older reconstructions where the climate system was not comparable. The abstract notes " The record is of high chronological resolution". This shows that higher than current CO2 concentrations have occurred in the recent past, and were not catastrophic.
I was surprised that this high CO2 content occurred at 12,750BP. This is around the cold of the Younger Dryas. So where did this CO2 come from?
NW Jack. The timing of the CO2 peak indeed looks like it immediately precedes or is co-incident the temperature fall at the start of the Younger Dryas.http://www.landforms.eu/Caithness/images/younger%2...
Re your comments about co2 and ice core data. The Vostok sample interval is roughly 2,000 years... so your comment that current CO2 levels are not unusually is probably completely valid. Thank you for the 'Bond Event' links.
Edit Dookie. So no opinion on the science then, just the usual ad hominem.
5 個解答
- NW JackLv 68 年前最愛解答
Having followed the link provided by Hey Duke, I found nothing about atmospheric CO2, nor this paper, but it is relevant in that it addresses the issue of generating hockey sticks by using low resolution proxy data, such as ice-core data for CO2, for past temperatures, and high resolution data such as measurements of the CO2 content of the atmosphere. Gases diffuse in the firn to some extent for decades before being more or less "sealed" in. (1) Thus, a reading for an individual year in an ice core is more like a moving average involving a number of decades rather than a snap shot. This eliminates the variability, and makes a more recent measurement with variability look unprecedented when it is not. Hey Duke's link was about temperatures rather than atmospheric CO2, but the same idea applies.
On page 18 of this link (2) is a comparison of CO2 concentrations found in ice-core bubbles verses CO2 found in the atmosphere by historical measurements. The ice core bubbles indicate an irrelevant CO2 hockey stick for modern CO2 concentrations. The direct measurements show that our current atmospheric CO2 concentrations are nothing special.
CO2 responds to ocean surface temperatures (3) due to reduced solubility in warmer water. (4) The Younger Dryas cold event (5) may have been the cold phase of a Bond event. (6) This means that the CO2 would have out gassed from the oceans during the warm phase immediately prior to Younger Dryas. (7) This may be what is happening now, but if so, it does not mean that anthropogenic sources are not partially responsible for the recent rise in atmospheric CO2. It also does not mean that CO2 is causal to any tipping point, but rather, it may simply be a symptom of the previous warm phase. Bond Events happen about every 15 centuries or so. (8)
Edit:
I am not adverse to the notion that CO2 may have been partly responsible for some tripping mechanism for Younger Dryas, but that is very speculative. It is known that CO2 not only has greenhouse properties (the ability to absorb 15 micron infrared emitted by Earth), http://www.randombio.com/co2.html
but also anti-greenhouse properties (the ability to absorb 2 micron red light emitted by the sun). (9) Whether CO2 warms or cools Earth depends on where in the atmosphere it is, what other gases are present, and what the concentration of CO2 is. Notice that there is less light arriving at 2 microns than there is trying to escape at 15 microns, and CO2's absorption capabilities at 2 microns are less than for 15 microns. To explain how higher concentrations of CO2 can change it from a greenhouse gas to an anti-greenhouse gas, consider the following simplified model of a fictitious greenhouse gas (FG) with similar properties:
@ 100 ppm
FG absorbs 90% of radiation at 15 microns until it is converted to another color so it can escape.
FG absorbs 10% of radiation at 2 microns
The energy coming in for the sample period and area is 100 J for 15 microns, and 10 J for 2 microns trying to come to Earth.
FG blocks 90 J leaving 10 J to continue at 15 microns.
FG blocks 1J leaving 9J to continue at microns
Net effect = 90 - 1 = 89 J warming effect => Greenhouse gas
@ 200 ppm:
FG blocks 90% * 10 J remaining after the 1st 10 ppm = 9J leaving 1 J to go on.
FG blocks 10% * 9 J = 0.9 J leaving 8.1 J
Net effect = 9 - 0.9 = 8.1 J = Week Greenhouse effect
@ 300 ppm:
15 micron: 90% * 1 J = 0.9 J more blocked. 0.1 left
2 micron: 10% * 8.1 J = 0.81 J blocked. 7.29 J left
Net effect = 0.9 - 0.81 = 0.09 J = No expected measurable effect
@ 400 ppm:
15 micron: 90% * 0.1 = 0.09 J and 0.01 J left
2 micron: 10% * 7.29 = 0.73 J and 6.56 J left
Net effect = 0.09 - 0.73 = 0.64 J = Very week Anti-Greenhouse Effect for the last 100 ppm.
At some point, CO2, like the Fictitious Gas above, begins to have an anti-greenhouse effect. I do not know exactly where, but there is no evidence that I can find that there is still a significant greenhouse effect for additional CO2 at present concentrations. Unfortunately, with smooth peaks instead of step functions, irregular peak sides, interference with other gas spectra, and different concentrations at different latitudes, http://meetingorganizer.copernicus.org/EGU2011/EGU...
and altitudes, http://www.mdpi.com/2072-4292/3/8/1603/pdf
the real world is not so simple for CO2. http://www.oism.org/pproject/s33p36.htm#Message598...
資料來源: 1) CO2 diffusion in firn http://www.igsoc.org/annals.old/10/igs_annals_vol1... 2) Ice-core & direct http://www.friendsofscience.org/assets/files/docum... 3) CO2 & Temperature http://www.woodfortrees.org/plot/hadsst2gl/from:19... 4) CO2 solubility http://en.wikipedia.org/wiki/File:Solubility-co2-w... 5) Younger Dryas http://en.wikipedia.org/wiki/Younger_Dryas 6) Bond Event http://en.wikipedia.org/wiki/Bond_event 7) Temperature Record http://en.wikipedia.org/wiki/File:Epica-vostok-gri... 8) 12 kyr Temperature http://en.wikipedia.org/wiki/File:Holocene_Tempera... 9) Absorption Spectra http://en.wikipedia.org/wiki/File:Atmospheric_Tran... - 5 年前
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- Hey DookLv 78 年前
I have not read the full paper, but I did read the title and the abstract, neither of which you quote. Had you bothered to even read those few sentences, you'd have realized how ridiculously misleading your framing of the article is in this "question." The main point of it has nothing to do with an apples-oranges comparison of past CO2 to the present levels. You would be more honest if you acknowledged recycling this cherry-picked distortion from Wattsup or some comparable anti-science fossil fuel industry propaganda site. http://wattsupwiththat.com/2013/03/11/a-simple-tes...
Edit: Since deniers on YA do not read (nor are 1 in a 1000 CAPABLE of reading) scientific journal articles, I looked instead to see which anti-science blog you were cribbing from. Double-checking, I can see that Wattsup probably wasn't it after all, because the Steinthorsdottir paper you link to shows up (Actually look a little harder, before you deny it, it IS there ) only as a COMMENT to Wattsup's piece on Marcott, not as the subject of a Wattsup Fossil Fuel Lie Recycling itself. Your anti-science blog source for this "question" was more likely one like this: http://hockeyschtick.blogspot.ch/ "New paper finds CO2 spiked to levels higher than the present during termination of last ice age"
I am fully able to "comprehend" the basic feature of the liar-denier echo chamber you fakers operate within. First copy, then paste, and -for a few YA deniers able to write at a post 10th grade level- rewrite slightly to thinly disguise. You did, it is true, quote the title, so I got that detail wrong previously, but not in a way that make it look like a title, or as a scholar would quote it in a citation, including lead author and journal, so I skipped over it the first time I read your "question." One can only read so many anti-science crap "questions" before resorting to skimming.
Speaking of wrong links, your jpg link does not include the "review" you quote just above it. That "review" shows up, as the first google hit, as coming from this anti-science blog:
http://www.climatedepot.com/a/20163/New-paper-find...
which (surprise, surprise) promises the "full article," but actually only links over here again: http://hockeyschtick.blogspot.ch/
Ah, the endless echo chamber of Heartland-Koch pseudo-science that is such a profound source of "comprehension."
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