File talk:Co2-temperature-records.svg

Would it be possible to have the same graph over 10,000 and 1,000 years? —Preceding unsigned comment added by 78.16.131.13 (talk) 19:25, 21 April 2009 (UTC)[reply]

I don't think its appropriate for a figure caption to have a lot of (contentious) science discussion on it. So I cut it all out. This should be discussion on the page that references this figure instead. Whatever the lag/leads are, they can't be properly seen on a figure of this scale anyway William M. Connolley 09:29, 9 November 2006 (UTC)[reply]

I disagree with this action. I propose the cut is reverted. Leland McInnes, it is your picture so you should retain ultimate editorial control. Chris Line, 9 November 2006

Please sign your messages (with ~~~~; better still, get an account). LM doesn't retain control, of course. Looking at what links here the answer seems to be nothing. Which is a bit odd... I thought it was used. But if its not linked, this entire discussion is pointless, as no-one will see it (another reason to have it in the article instead) William M. Connolley 10:29, 9 November 2006 (UTC)[reply]

You can link to the page by clicking on the image at the 'Global Warming' page. The editing of this page is restricted and the discussion could not be written in the main article. Although some of it may be more appropriate there as you suggest. Chris Line, 9 November 2006

OK, it *is* linked from the GW page, but doesn't show up in what-links-here. Odd. William M. Connolley 11:26, 9 November 2006 (UTC)[reply]

Can we at least agree that the temperature signal leads the CO2 signal? You can see this, particularly in the Vostok data. You can also check it statistically by computing the cross-covariance of the two signals using the original data. Chris Line, 9 November 2006

We could, but then the question would be, why are you so keen on that particular factoid? I ask because this is a common skeptic argument in the GW wars. As a fact, its semi-OK (though there are complexities: T is from the ice, and CO2 from the bubbles, and getting these onto the sam age scale is non-trivial). But the implication that people like to leave dangling from it (CO2 doesn't affect T; its the other way round) is wrong. I still think the text better belongs on an article page, but which? William M. Connolley 11:26, 9 November 2006 (UTC)[reply]

I realize this is an exceptionally old comment but what is the basis of the statement? Does the commentor believe that bubbles form across multiple years or some in a year OTHER than when the ice layer is layed down? I think this comment shouldn't stand on its own if the commentor is actually trying to provide information instead of invective. If what you say is true and if what the assumption you're ruling out is false then there should be readily available peer-reviewed documentation to back up what you say - otherwise it's just more hearsay. Can you please provide a few references? 157.185.95.27 (talk) 19:03, 16 January 2014 (UTC)mjd 2014-01-16-14:03EST[reply]

With a little more research and thought I think this comment is really wrong in the sense of what it was tying to accomplish. That fact is, that gases in the very highest layers of a forming core (the firn) do have some mobility So there is some blurring of the dates in the gas data. But, what this means is that a gas concentration is going up in the atmosphere the gases already trapped in the firn a few years or possibly even decades earlier with lower gas concentrations are going to have their concentrations enhanced by the higher concentrations above. This means that if a particular gas concentration LEADS temperature in the atmosphere the ice core data is going to make the gas look like it leads the temperature even more, not less (much less lag as it appears it does in the Vostok core). Conversely, if on the other side of the event a particular gas concentration is deceasing in the atmosphere and LEADING temperature down then higher concentrations of gas in the ice a few years down or a few decades down will lose some of their increased concentration to higher layers. So the gas concentration will appear to go down BEFORE the temperature goes down (again, the opposite of what is shown on the Vostok core. This is a fundamental result of signal theory that this type of communication/interaction between layers will broaden the signal, but in this case there doesn't seem to be any mechanism to *delay( the signal, as Connelley's statement asserts. It's certainly possible, but that assertion needs to be referenced. Where is the reference that shows how gas concentrations in ice cores are DELAYED with respect to the atmosphere? 157.185.95.27 (talk) 19:46, 16 January 2014 (UTC)mjd 2014-01-16-14:46EST[reply]

The text might belong on the article page where the picture appears. Or it could be retained in its original location. Chris Line

I am keen because the matter is very important to us all and our planet. We should be able to discuss the facts and their implications. Chris Line, 9 November 2006

If this forms an argument for those who are skeptics of global warming then it is important that a counter-argument is available. We should be able to justify our views. Chris Line, 9 November 2006

Revert the changes? Add to the discussion if you would like and explain as you have in your comment? Chris Line, 9 November 2006

I don't think many people are watching this image page, unlike say the GW page where people *are* watching. So if you want a decent discussion, don't have it in this dark corner. As for the science, try: http://www.realclimate.org/index.php/archives/2004/12/co2-in-ice-cores/ William M. Connolley 11:55, 9 November 2006 (UTC)[reply]

I will take a look and consider your suggestion. Although, it is late getting late here so I best get some rest soon and say goodnight. (Chrisnumbers2000 11:59, 9 November 2006 (UTC))[reply]

It is a good article. Cheers. (Chrisnumbers2000 12:11, 9 November 2006 (UTC))[reply]

WMC, if temperature & CO2 are operating on a mutual positive-feedback loop (i.e., warming causes CO2 release, which causes more warming, which releases more CO2 and so on) as your link claims, shouldn't the earth have undergone a runaway greenhouse effect a long time ago? Your source doesn't seem to mention anything about what brings the temperature back down. If you've got info on the subject, I'd like to see it. 130.36.62.140 20:07, 9 November 2006 (UTC)[reply]

Actually, the original Science article referenced in the RealClimate piece that Connelley posted above CLEARLY demostrates that not only is the CO2 lag real (not the result of some problems with dating the bubbles accurately, as stated by Connelley above) and that the lag is 800+/-200 years. The authors of the article then argue that since the glacial Termination events last 5000 years and since the lag is only 1/6th of that then the CO2 can still act over the remaining 5/6th of the Termination event and cause feedbacks to increase temperature. The only problem with that argumentis is - and anyone with eyes can look at the graph and see - that essentially ALL of the temperature increase of each Termination event recorded in the Vostok core happens in the first 800 years of the event. That is - temperature doesn't go up MORE as result increased CO2 (i.e., there is no discernable positive feedback mechanism) but in fact as CO2 increases dramatically in the ice core data the temperature responds by HALTING its increase. So that pretty much puts a nail in the coffin of the original contention that the lag is fictitous and caused by uncertainty in bubble dating (unless someone has another reference on that?) and the core data itself on simple visual inspection argues against a strong positive feedback for suddenly rleased CO2. 157.185.95.27 (talk) 20:34, 16 January 2014 (UTC)mjd 2014-01-16-15:34EST[reply]

Some of the feedbacks are limited (vegetation related, say). However, I believe that where exactly the glacial-interglacial CO2 comes from isn't really known William M. Connolley 21:40, 9 November 2006 (UTC)[reply]

I like the improvement. The progression of the time axis from left to right appears more standard and facilitates a standard interpretation. (Chrisnumbers2000 13:20, 20 January 2007 (UTC))[reply]

In the 250+ years we have been burning coal and gas, only the last ~100 have been on a massive scale and it is difficult to asses the effects if any we may have had. Not to mention, C02 is not necessarily the primary greenhouse gas as others are many times as potent, take methane and certain bromides. While the temperatures have obviously been slightly increasing since the industrial age heated up, feedback effects on this planet tend to be negative, up to a point, as in biological systems. On a planetary scale a positive feedback loop means fluctuating temperatures, not just nice steady warming. The main concern is the health of the ocean life which allows us to live. (2/3 of oxygen anyone?) —Preceding unsigned comment added by 75.165.105.221 (talk) 03:59, 7 May 2008 (UTC)[reply]

Just curious, why use delta-deuterium instead of delta-18O, and what implications (if any) does this have for the interpretation? I'm not a paleo guy, so this could be a dumb question... Raymond Arritt 18:22, 9 November 2006 (UTC)[reply]

I was simply working with available data. The Antarctic cores seem to have gone with delta-deuterium, while Greenland cores went with delta-18O. My (admittedly limited) understanding is ultimately it makes little difference, and it is consistency (within each core sample) that counts, so it's probably just one of those historical accidents as to which was initially measured. Leland McInnes 20:29, 9 November 2006 (UTC)[reply]

There is, as far as I can see..., no temperature scale on the y axis. (Also, the reversed time axis may be confusing).Narssarssuaq 00:23, 28 November 2006 (UTC)[reply]

It was confusing. I've noted that the scale is deuterium, a temperature proxy William M. Connolley 09:40, 28 November 2006 (UTC)[reply]

Not only that, the current C02 level is prominently shown, but the current duterium level is omitted.

The implication of the graph is that the C02 level and duterium level are connected. Then to show the current C02 level, the intention is to say, look, given the connection, we are well outside the historical record, so it must mean that temperatures are much higher.

However, not showing current levels has probably been done because even though the current C02 levels are high, the deuterium levels aren't.

Nick

What the hell? The present C02 level varries enormously depending on who you talk to. What bothers me is that the graph is cited, but it doesn't say where this "present C02 level" information comes from. Don't remove the arrow, but PLEASE get some kind of citation for it. --24.239.174.223 16:17, 7 January 2007 (UTC)[reply]

Don't understand "various enormously", since it doesn't. See Greenhouse_gas. Current value is about 383 ppmv, with regular seasonal variation of about 8 [1] William M. Connolley 17:25, 7 January 2007 (UTC)[reply]

The "varies enormously" was me misreading some stuff. My bad. Still, a citation would make it look better if nothing else.

--24.239.174.223 22:11, 13 January 2007 (UTC)[reply]

I have seen a documentary on global dimming that suggested that evaporation follows humidity, wind, and sunlight more than temperature. I think that the conclusion that the deuterium is an indicator of just temperature needs to be checked. I see it as fallacious. Large scale erruptions, forest fires, desertification will change all this. Besides the argument about the local sources of the evaporated water changing holds water. They follow wind currents not temperature. Finally what about CO2 diffusion in ice? 67.72.98.108 01:48, 8 June 2007 (UTC)[reply]

The use of deuterium as a T proxy is well established, as are various errors/problems/complications (take your pick). But you'll need to read up on that science if you want to criticise it - your opinion from a TV prog isn't good enough William M. Connolley 09:06, 8 June 2007 (UTC)[reply]

Goes back to ~800 kyr: http://doi.pangaea.de/10.1594/PANGAEA.710901?format=html

William M. Connolley (talk) 23:54, 10 January 2009 (UTC)[reply]

Thank you. I've made the relevant updates. -- Leland McInnes (talk) 21:04, 11 January 2009 (UTC)[reply]

This is the link for the ice core CO2 data. What is the source of the delta-deuterium data? Thanks... 157.185.95.27 (talk) 18:54, 16 January 2014 (UTC)mjd 2014-01-16-12:55EST[reply]

Science types get it immediately. Everyday folks do not. Many will miss the point of the "Current CO2 level" arrow altogether - simply because the trend is compressed so tightly over time that you can not see the time-lapse effect of human impact. I think the graph should be left as is: but also present another 1,000 or 10,000 year graph with: Pre - 1800 A.D. minimum CO2 and Pre - 1800 A.D. CO2 max lines. Min and Max bars that cut across the whole picture left-to-right. Even add a legend or tag to effect: "CO2 remained inside these limits over 800,000 years of measurable data." So now people can then extrapolate backward and still see a TREND.

Point is: Here is REAL data. There is a TREND. P.S. I linked to your graph on my blog. THANK YOU FOR TAKING THE TIME TO PROVIDE IT. It is a labor of love worthy the highest praise. Thanks, Kyle Sager—Preceding unsigned comment added by 74.190.51.92 (talk) 16:57, 27 October 2009 (UTC)[reply]