Talk:Attribution of recent climate change

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Some POV problems[edit]

1. The phrase "The current best answer is..." is incredibly POV and inappropriate for this article. While it is true that some people may believe that it is "the best answer", that doesn't necessarily mean it is and it certainly should be reported as fact when it is opinion.

3. It is absolutely inappropriate to discuss the issue of greenhouse gas emission in the second paragraph without including discussion of the fact that the majority of greenhouse gas emissions has taken place AFTER the reported increase in global temperatures. Anything else is POV pushing.

3. "A summary of climate research may be found in the IPCC assessment reports". That isn't either accurate or sufficient. The IPCC doesn't summarize all climate research, it creates its own summary. So this phrase must be changed to reflect this fact. I suggest something like "An IPCC summary of climate research may be found in their assessment reports".

<My POV> I am currently undecided on the issue of anthropogenic global warming (I have changed my mind about three times today), but I am opposed to any single organisation dominating any given field of research </My POV>. A read through of this article made my POV hackles rise. Five of the top eight references are IPCC. This may as well be titled "The opinion of the IPCC and ridicule of skeptics". If the theory linking warming on other planets to that on earth is 'nuts' (uncommon scientific terminology), why include it? Simply to ridicule skeptics? Article needs NPOV work IMHO, but I'm not going to waste my time making changes that will be reverted instantly. Dhatfield (talk) 14:32, 8 January 2008 (UTC)
Cl Ch is unusual in that there is one body - IPCC - charged with collecting and collating and summarising reseach. IPCC doesn't dominate the research enterprise, but it does provide the best summary. And (once again) its work has been endorsed by X, Y and Z. Warming on other planets is different (you're right: it is basically nuts and has no scientific support, its only here because it comes up from the septics). Not making instantly reverted edits is a good idea. As always, you're free to discuss POV-type improvements here William M. Connolley (talk) 22:56, 8 January 2008 (UTC)
Unusual is one way of putting it. Unique would be another way. Why does the article not reference the fundamental research? Is primary research not preferable to referencing a third party in an encyclopedia? As an aside, is this http://en.wikipedia.org/wiki/Image:Climate_Change_Attribution.png really the best we, as a species, can do? It ends in 1994. Dhatfield (talk) 10:42, 23 January 2008 (UTC)
Though this discussion seems over, I'd like to point out that at least in this case, secondary research is DEFINITELY preferable to primary, although relying on one source is indeed a problem. In general, interpreting primary research is NOT the job of an encyclopedia, and on Wikipedia qualifies as OR. In this particular case, there are literally thousands of studies that need to be compiled, statistically analyzed, and interpreted; citing individual studies would be useless. As for the graph, I'm not exactly sure what the objection is. Eebster the Great (talk) 03:41, 21 January 2009 (UTC)

Solar variation[edit]

I don't like the current version of the "solar var" section; it reads too much like endorsing it. Quotes from the various articles linked need to be pulled in to make it clear that the people observing this stuff aren't claiming it. It would be nice to find a way to note how weak the stuff is - eg the pluto and neptune stuff is a trend from 2 points William M. Connolley 21:07, 7 October 2007 (UTC)

The section is poorly written. The entire section about the solar variation only speaks about mostly unrelated climatic changes on other planets, which it shouldn't. ~ UBeR 21:17, 7 October 2007 (UTC)
My recollection is that this is a leftover from an old edit war. Somebody put in the nonsense from Abdusamatov when he was in the news, then some of us added the responses, so here it is. Delete as much as you like. Raymond Arritt 21:52, 7 October 2007 (UTC)
Now that section reads like it is totally bashing the concept... I'm totally clueless on this subject matter, so unless it is supposed to read like that (i.e. the concept is just some scientists making crazy assumptions and is ridiculous to pretty much the rest of the scientific community), can someone make it more neutral? wctaiwan (talk) 14:49, 7 January 2008 (UTC)

A river in Africa?[edit]

Re [1] - I'm with Hermione. This is a science article; CCD is primarily political William M. Connolley (talk) 13:11, 2 March 2008 (UTC)

I agree, i don't know what i does on the Attribution article, the connection would have to be rather far-fetched. --Kim D. Petersen (talk) 19:35, 2 March 2008 (UTC)

Sulfur vs Sulphur[edit]

William, I realise that you take a special interest here, so would you please reconsider the reversion of edits to make the article consistent with WP:SULF. Normally, I would applaud the use of the <POV> correct </POV> spelling, but global standardisation is a Good Thing. Dhatfield (talk) 15:14, 2 April 2008 (UTC)

Sorry, but I'm a fanatic on this issue. I'm also a bit sick of having SULP quoted at me, because I can't help feeling that people don't actually read it: it sez quite clearly These international standard spellings should be used in all chemistry-related articles and this is *not* a chemistry-related article, its climate. And Sulphate is the preferred IPCC spelling William M. Connolley (talk) 21:43, 6 April 2008 (UTC)
Obviously all those atmospheric chemicals have nothing to do with chemistry :) Take away all those pesky chemicals and there'd be no problem - global warming wouldn't exist...
Of course it is a chemistry related subject and no, IPCC doesn't dictate spelling on Wikipedia - WP policies and conventions do.
And, yes WMC and I have discussed this before, rather heatedly as I recall. Now, what is the consensus? Go with WP guidelines and IUPAC on this obviously chemistry related series of articles - or follow IPCC and WMC's personal preferences? Vsmith (talk) 00:04, 10 April 2008 (UTC)
I'm all for standardization so I'd say follow WP:SULF but I really care very little one way or the other. Oren0 (talk) 00:36, 10 April 2008 (UTC)

Water vapor[edit]

See Talk:Global_warming/FAQ#Water_vapour_is_the_most_important_greenhouse_gas.21 on why water vapor is a greenhouse gas, but not a climate forcing. --Stephan Schulz (talk) 08:28, 6 April 2008 (UTC)

To be honest, I don't understand why this edit of mine was reverted: [2]
It was trying to get the point across that yes, water vapour is the dominant greenhouse gas, but no, it's not a factor in recent global warming, which presumably we all agree on. Can we not find a compromise based on that? --Merlinme (talk) 08:22, 7 April 2008 (UTC)
I don't know why you were reverted, but one problem is certainly "naturally occurring water vapor". The amount of WV in the atmosphere depends primarily on the temperature. If CO2 pushes the temperature up, is the added WV "naturally occuring"? --Stephan Schulz (talk) 14:49, 7 April 2008 (UTC)
Well, I don't know; I wasn't actually particularly expecting my edit to stand unaltered, but I wasn't expecting it to be reverted either. By all means improve it, but NewtonianWiki appears to have a point to me; a) that the section should be called anthropocentric greenhouse gases (or, possibly, forcing greenhouse gases); and b) it needs to be explained to a Wikipedia reader why water vapour is not relevant. My edit was attempting to provide this information. I'm happy to have it improved, but I don't think ignoring the issues raised (by reverting) helps. I'll have a second attempt. --Merlinme (talk) 15:42, 7 April 2008 (UTC)
I'm not convinced. Water vapor is a red herring here. Nobody seriously claims that its a climate forcing. It's a standard tactic of sceptics to confuse the overall greenhouse effect with the anthropogenic greenhouse effect and then to claim "look, its all due to water vapor, not CO2". If we start listing things not responsible for global warming, we will have a fairly long list soon ;-). --Stephan Schulz (talk) 16:31, 7 April 2008 (UTC)
The relevant point to me is that the section is headed "Greenhouse gases". Red herring or not, water vapour is a greenhouse gas. Alternatively, come up with a section heading which better explains what the section holds. I'd be a bit unhappy with "Forcing greenhouse gases" though, because it's not a term the average encyclopedia reader could be expected to understand. It would need to be explained; simply calling the section "Greenhouse gases" and having a short sentence on water vapour probably deals with the "red herring" quicker. Whatever solution is adopted, I would hope it aids a reader's understanding rather than confuses it. --Merlinme (talk) 17:20, 7 April 2008 (UTC)
So then you disagree with the language at greenhouse gas: "water vapor acts as a positive feedback to the forcing provided by greenhouse gases such as CO2." Should I go ahead and remove that? There's a difference between listing everything not responsible for global warming and listing a major greenhouse gas when talking about greenhouse gases and explaining its effect on climate. Oren0 (talk) 16:40, 7 April 2008 (UTC)
Nope, that sentence is entirely correct. WV is a feedback, not a forcing. --Stephan Schulz (talk) 16:43, 7 April 2008 (UTC)
..and now, we state that water vapor "is responsible for 36-66% of the greenhouse effect". While correct, this gives the wrong impression of a wrong uncertainty, while the range does not describe an uncertainty, but rather is caused by the non-additive nature of GHG mixing and depends on which question is asked. --Stephan Schulz (talk) 16:57, 7 April 2008 (UTC)
Fine, it's a feedback not a forcing, therefore it's still important to GW, right? The current revision seems to dismiss it outright. As for the 36-66% number, I took it directly from greenhouse gas and RealClimate. Oren0 (talk) 17:11, 7 April 2008 (UTC)
Indeed. The numbers are correct. Assuming you understand them, do you really think the average reader will understand the fact that which value in that range one picks is more a matter of definition than of uncertainty? Yes, water vapor is a feedback. So I would suggest we describe it as a feedback in a separate paragraph, especially as it amplifies any warming, not just GHG induced warming. --Stephan Schulz (talk) 18:19, 7 April 2008 (UTC)
Fine with me. I think that leaving water vapor out was a glaring omission. If you think it can be explained better in its own paragraph, fine. I also don't like the idea of leaving out data because you think the average reader is too dumb to interpret it properly. Oren0 (talk) 18:49, 7 April 2008 (UTC)
Good thing then that that is not my reason. But everything in its place...there is a good reason why neither The Art of Computer Programming nor Decline and Fall of the Roman Empire are assigned reading for high school students. --Stephan Schulz (talk) 19:43, 7 April 2008 (UTC)
Sure, but this is an encyclopedia, not a work of literature. In my opinion it should be possible for a reasonably informed reader to achieve a good basic level of understanding of a subject from reading an encyclopedia. Speaking for myself, I did neither physics nor chemistry past 16, but I take an interest, and I would like to think I have achieved a good basic level of understanding of global warming through reading Wikipedia. To completely miss out water vapour in a paragraph headed "Greenhouse gases" is to do the reasonably informed reader a disservice, because either it leaves them not realising water vapour is a greenhouse gas, or it leaves them wondering why it's been missed out. In either case I would argue not having the subject clarified makes them more likely to believe misinformation on the subject. You don't explain something to someone by ignoring it. --Merlinme (talk) 07:34, 8 April 2008 (UTC)

editing footnotes[edit]

Several footnotes should be attributed to Gavin Schmidt (not "gavin" or "Gavin Smith" or other mistakes). But I cannot figure out how to edit them--they don't seem to show up in the editing page. Haven't been active lately, so have forgotten how to do this.

Jeeb (talk) 14:28, 27 June 2008 (UTC)

The footnote text is where the reference is made, not in the references section (to be more exact, it's at one of the places where the reference is made, but usually there is only one). --Stephan Schulz (talk) 14:33, 27 June 2008 (UTC)
Oh, you are right. I have corrected the references now. Splette :) How's my driving? 14:57, 27 June 2008 (UTC)

Amusing rant[edit]

Who the hell decided this article should be called "attribution of recent climate change?" This should be changed to "causes" IMMEDIATELY. I mean, seriously, the English language does not use the word "attribution" in this manner, at least not in America at any sort of reasonable level. I'll wait a few days, if it's not fixed, I'll do it myself. —Preceding unsigned comment added by 140.112.185.129 (talkcontribs)

Don't William M. Connolley (talk) 07:03, 22 July 2008 (UTC)

"Attribution" is less loaded than "causes" and seems to imply a more rational and scientific stance.The whole climate change debate is so politicised that the anthropomorphic aspect dominates the subject.If we attribute climate change to human activity, we understand it better than to say we "caused" it, as in accusing ourselves of wrong doing,ignorance,etc etc.Example;Recent legislation in California seeks to make high energy consuming big screen plasma televisions more energy efficient.One clown politician jumped on this and argued that next there would be laws limiting playstation use to an hour a day.USA=the consumers dream continues in the fog of childhood.I note there is no quick link to " Global warming controversy"?Should there be a link to this article found in wikipedia?If so,I don't know the way to enter it.ThanksErn Malleyscrub (talk) 06:32, 22 November 2009 (UTC)

Attribution is appropriate process when there are multiple causes to be sorted out. What is unfortunate, is that the article neglects to attribute bias in beliefs as a cause. Zulu Papa 5 ☆ (talk) 22:41, 27 November 2009 (UTC) This is becoming ridiculous.To state bias in beliefs is a cause is to return to burning witches and superstition;stick with facts and proof.If you have evidence of "bias" state clearly facts to show this.Science disputes "belief" as any influence on the real world except in the minds of believers.Superstition has no place here,thanks.Ern Malleyscrub (talk) 12:33, 5 December 2009 (UTC)

250 years ago?[edit]

This sentence needs some clarification:

While 66% of anthropogenic CO2 emissions over the last 250 years have resulted from burning fossil fuels, 33% have resulted from changes in land use, primarily deforestation.

I seriously doubt that there was any substantial impact on CO2 levels from burning fossil fuels during the 18th and 19th centuries. Steohawk (talk) 22:38, 25 August 2008 (UTC)

Hmm, the sentence makes perfect sense to me. It refers to the the percentage of fossil fuel vs.land change related CO2 emissions of the cummulative total anthropogenic emissions in that time, regardless of how these are distributed over these 250 years. Of course the last few years contributed the most to that... Splette :) How's my driving? 23:04, 25 August 2008 (UTC)

Positive feedbacks[edit]

I think this article needs more on positive feedbacks. Here's a science summary http://www.eurekalert.org/pub_releases/2009-02/su-ccl021009.php

Unless there's widespread disagreement, I'll start making some edits soon.Andrewjlockley (talk) 12:19, 15 February 2009 (UTC)

That's a press release, not a science summary. It also mostly affects future effects, not recent climate change. I think most of that (if sourced to better sources) should go into Effects of global warming, which already has a feedback section (and covers most of the material). --Stephan Schulz (talk) 12:49, 15 February 2009 (UTC)
Per Stephan, consider this disagreement widespread. -Atmoz (talk) 15:37, 15 February 2009 (UTC)
The feedback effects are based on peer-reviewed science. Is that not popular in this article?Andrewjlockley (talk) 17:52, 15 February 2009 (UTC)
Then start with the science, not with press releases William M. Connolley (talk) 18:56, 15 February 2009 (UTC)
Sadly the science has been edited out previously. Can I assume that I'm now free to include it, now that there seems to be little doubt that the 4th report is, as i have been saying all along, utter rubbish?Andrewjlockley (talk) 00:18, 16 February 2009 (UTC)
What? --Stephan Schulz (talk) 00:25, 16 February 2009 (UTC)
I'm no longer going to put feedback effects in here. The point I was making above was simply that the IPCC report 4 underestimates climate change so badly as to be entirely misleading.79.65.169.132 (talk) 17:36, 16 February 2009 (UTC)
You've said that several times, it gets very boring. After asking you to learn to log in, we've replied "do it from papers not press releases" and then you go away William M. Connolley (talk) 17:57, 16 February 2009 (UTC)
Quit the personal attacks william, I've simply stated that THIS ARTICLE is not the right place, because it's FUTURE impacts I'm talking about. The quote from Field was entirely appropriate, as discussed on the GW talk. I'm just about to edit the GW article now, as per the '24hrs on talk page' policy. So get ready to make some more entirely unconstructive comments and arbitrary reversions.Andrewjlockley (talk) 09:09, 17 February 2009 (UTC)
The "'24hrs on talk page' policy" is somewhat new to me. It seems like a reasonable idea IF you participate in a constructive dialog during that time. --Stephan Schulz (talk) 10:02, 17 February 2009 (UTC)
It seems a good way of preventing an edit war!Andrewjlockley (talk) 01:38, 18 February 2009 (UTC)

Has the issue of the quality of the climate record been addressed here?[edit]

What I'm thinking of is McKitrick, Ross and Patrick J. Michaels (2004). "A Test of Corrections for Extraneous Signals in Gridded Surface Temperature Data" Climate Research 26 pp. 159-173. full text -- and similar papers that discuss the problem of the poor quality of the instrumental record.

The obvious question is: can we really (empirically) detect the signal of AGW in the noise of poor-quality temp records: from Heat-island contamination (McKitrick's argument), weather-station site issues, instrumental-calibration issues, etc.

Thanks in advance for pointers (to the archive?) and comments, Pete Tillman (talk) 00:11, 12 September 2009 (UTC)

I would suggest to discuss this not here, but at Instrumental temperature record. --Stephan Schulz (talk) 00:31, 12 September 2009 (UTC)

What is the connection?[edit]

I find it very difficult to understand from this article why the major scientific bodies have determined that recent global warming is primarily caused by human activity. It is not enough to just say "most of the major bodies have determined it is so." Why? What is the evidence? Yes, certain gasses have increased in the atmosphere due to human activity, and the planet is warming. But how do we know that these two are connected to each other? What is the evidence? It is really hard for an average reader to gain this information from this article. I get the feeling that the emperor has no clothes. --Westwind273 (talk) 16:17, 6 October 2009 (UTC)

We have Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations."[2] and 2 is a link to a publically available document. You could read it.
Or you could read further on and get to: Evidence for this conclusion includes: * Estimates of internal variability from climate models, and reconstructions of past temperatures, indicate that the warming is unlikely to be entirely natural. * Climate models forced by natural factors and increased greenhouse gases and aerosols reproduce the observed global temperature changes; those forced by natural factors alone do not[10]. * "Fingerprint" methods indicate that the pattern of change is closer to that expected from greenhouse gas-forced change than from natural change.[11] William M. Connolley (talk) 16:32, 6 October 2009 (UTC)
....and then there is the link to greenhouse gas that explains the basic mechanism of the greenhouse effect. What is really impressive is that Svante Arrhenius correctly predicted the effect more than 50 years before we had good CO2 measurements or a reliable temperature record. --Stephan Schulz (talk) 16:44, 6 October 2009 (UTC)
I personally find the most helpful section Attribution of 20th century climate change. There the article discusses different possibilities for the observed increase in global temperatures. While it is difficult for a scientist to make a definitive statement on something which has so many variables, there is essentially universal scientific agreement on the following things: 1) global temperature is going up 2) human activities (fossil fuel burning, forest clearance, farming etc.) raise global temperature 3) most of the recently observed increase is due to human activities. The evidence for 1) and 2) is enormous; 3) is slightly more contentious, but as the article notes, recent studies by scientists from many different countries (i.e. the IPCC) have concluded that it is "very likely". As I understand it, the evidence for this is mainly that scientific models of the atmosphere which include human components predict the observed increase in temperature much better than those which don't. That's what the graph is about; before about 1950, the effect of greenhouse gases on changes in global temperature was less than that of solar activity. Afterwards the effect of greenhouse gases gets steadily larger, although initially the effect of this was masked by sulphate pollution, which reduces global temperatures. A model which takes into account changes in greenhouse gases, solar activity, ozone, volcanic activity and sulphates provides a good match to observed changes in temperature. It doesn't provide a perfect match, but then no models do. It certainly provides a far better match than models which ignore greenhouse gases, the effects of which have got a lot stronger since 1990. Essentially all the scientists who've done research in this area find this evidence convincing; no-one has come up with a model which can "explain away" the effect of greenhouse gases.
Just because it is complex does not mean that the evidence is not pretty clear; it annoys me when people say "but that isn't the case" without providing any evidence or intellectual justification for such a statement. People say "yes, but theory X has now been shown to be wrong"; true, but that was because theory X disagreed with the evidence, so a theory was created which better fitted the evidence. By contrast, the evidence currently available strongly supports a significant anthropomorphic global warming effect; and there are no plausible competing theories.--Merlinme (talk) 17:56, 6 October 2009 (UTC)

I do feel some sympathy though for the view that there is too much "this report supports the view" and not enough actual evidence referenced William M. Connolley (talk) 20:06, 6 October 2009 (UTC)

Well in the end I got bored of pasting it together from IPCC quotes and just made something up William M. Connolley (talk) 20:32, 6 October 2009 (UTC)

"Climate models forced by natural factors and increased greenhouse gases and aerosols reproduce the observed global temperature changes; those forced by natural factors alone do not[10]. "Fingerprint" methods indicate that the pattern of change is closer to that expected from greenhouse gas-forced change than from natural change.[11]" Yes, but how? As far as I know, warming is warming. There have certainly been periods in the past where the earth has warmed naturally. What is it about this warming that indicates a human cause? What is the "fingerprint" of this warming that shows it is caused by humans and not natural? This article should not simply pass off such questions to "go read the footnote references". This issue is the whole reason why conservatives say their is no global warming problem. To gloss over these important questions, simply reinforces the conservative argument. I myself seriously wonder whether we have solid evidence that global warming is caused by humans, given that proponents seem to avoid these important questions. Merlinme's #3 is really what this whole article is about. If #3 is contentious, then the whole argument collapses like a deck of cards. --Westwind273 (talk) 15:13, 7 October 2009 (UTC)

I don't understand your problem. What is there about Climate models forced by natural factors and increased greenhouse gases and aerosols reproduce the observed global temperature changes; those forced by natural factors alone do not that you didn't understand? That isn't all the evidence, but it is a large part of it William M. Connolley (talk) 15:29, 7 October 2009 (UTC)
If you can't understand the footnotes, and refuse to accept the word of people who do understand them and don't particularly have an axe to grind, then I'm afraid we're not going to get very far.
Point 3 isn't that contentious. Given my (admittedly limited) understanding of the science, the fingerprint is simply that where there are more of the greenhouse gases being released by humans, we get more warming. We don't get more of anything else known to cause warming (as the article notes, if anything known "natural" factors would be expected to be reducing temperature at the moment). WMC might be able to explain the point better.
If you disagree with this point, then feel free to do your own research into the sources. Hell, do your own original scientific research if you wish. If you managed to find the "missing link" that is natural and causing all this warming, without involving human causes, then you'd probably deserve a Nobel prize. But I doubt that you will. The fact is that every scientist who has done the research thinks that humans are causing a significant amount of the warming (and a large majority would say that humans are "very likely" causing most of the warming).
If you disagree with all these scientists, well I guess that's your prerogative. But in the absence of any scientifically plausible evidence supporting your position, your position is more in the realms of conspiracy theory than scientific theory. --Merlinme (talk) 15:34, 7 October 2009 (UTC)
Fingerprints include e.g. the fact that we have stratospheric cooling at the same time that we have tropospheric warming and the fact that the Arctic heats up faster than the middle latitudes. Different sources of warming have different effects, and the effects that we observe are consistent with GHG induced warming and effects from land use. Increases in solar radiation, e.g., would cause stratospheric heating as well as tropospheric heating. But again (and again....and again): We understand the greenhouse effect from first principles. More GHGs means more warming. Even Lindzen agrees with that, he only speculates about some compensating effect via clouds. --Stephan Schulz (talk) 15:51, 7 October 2009 (UTC)
The fingerprint stuff actually gets quite tricky and heads off into EOF/PCA land. We link to the TAR section on this [3] for anyone who cares for the grungy details William M. Connolley (talk) 16:58, 7 October 2009 (UTC)
On the specific issue of previous global warming (which cannot have been caused by burning fossil fuels), it is quite an interesting area, and is discussed in (exhaustive) detail at Paleoclimatology. There are complex effects involving changes in solar radiation, ice, and atmospheric feedback processes. However, to take one of the most recent global examples, the Holocene climatic optimum raised temperature in some parts of the world by as much as 4 degrees C. However the effect on global temperature was probably close to zero, and the warming took place over hundreds or thousands of years. Similarly, the Paleocene–Eocene Thermal Maximum did raise global temperatures by about 6 degrees C, but it took 20,000 years. By contrast, current warming is expected to reach about 2 degrees C after about a century, which is light speed in terms of geological processes. All the available evidence which we have (e.g. measured solar radiation etc.) suggests that natural phenonomena cannot explain the rise, whereas a human cause fits the evidence well. --Merlinme (talk) 12:27, 8 October 2009 (UTC)

The number of Americans who believe in global warming has declined by 20 percentage points in recent years. See http://news.yahoo.com/s/ap/20091023/ap_on_sc/us_climate_poll;_ylt=AvXSu6fsBisf5SrVsViFvk6s0NUE;_ylu=X3oDMTMxaG1naWFxBGFzc2V0A2FwLzIwMDkxMDIzL3VzX2NsaW1hdGVfcG9sbARjcG9zAzcEcG9zAzQEcHQDaG9tZV9jb2tlBHNlYwN5bl9oZWFkbGluZV9saXN0BHNsawNwb2xsdXNiZWxpZWY- I think the reason for this decline is exemplified by the rude way my questions have been treated on this page. Those who believe in global warming seem to dismiss as 'stupid' those who want clarification of the evidence. My main point here is to improve the article, which is what this page is for. My main point is that the explanations of why we know global warming is not nature-caused is something too important to simply be dismissed to "go read the footnotes" or "trust the scientists". Those who have commented here have not read what I have been saying all along. It is not that I don't understand the footnotes; that is not the issue. My point is that an explanation of the reasoning for man-caused warming is too important a point to be relegated to the footnotes. I don't know how much clearer I can say it. If you think that those of us on the fence should just read the footnotes or trust the scientists, then you are sticking your head in the sand while public opinion is changing against you. Those who are posting here actually have trouble articulating just what the evidence is (e.g. "The fingerprint stuff actually gets quite tricky"). By sifting through all that was written here, I can kind of pick out a few reasons why the warming is manmade, not global. You seem to be saying that the location of the warming indicates it is only manmade, or the pace of the warming cannot be mathematically attributed to nature. But it is really hard to pick these things out amongst all your misunderstanding of what I am saying. And absolutely none of this explanation is contained within the article. Thus American public opinion continues to slide against global warming. Without a proper and clear explanation of what it is about the warming that indicates man-made, many of us are left with "The emperor has no clothes." --Westwind273 (talk) 03:20, 23 October 2009 (UTC)

WMC wrote: "I don't understand your problem. What is there about Climate models forced by natural factors and increased greenhouse gases and aerosols reproduce the observed global temperature changes; those forced by natural factors alone do not that you didn't understand? That isn't all the evidence, but it is a large part of it." WMC, you are not reading what I am writing. In what way do the "observed global temperature changes" of manmade warming differ from the changes "forced by natural factors alone"? Your quoted sentence does not explain this. Are the locations (longitude and latitude) of manmade warming different from those of natural warming? Is the pace of manmade warming different from the pace of natural warming? Does manmade warming happen at different levels in the atmosphere than natural warming? Is natural warming of the past caused by factors like solar flares which are not happening now to explain the warming? I'm trying to help you by throwing out a bunch of possibilities here. The main article should explain this. Otherwise public opinion will continue to slide. --Westwind273 (talk) 03:30, 23 October 2009 (UTC)

WMC said "we don't care how many americans believe what". I'm not sure that's quite right; it would be more correct to say "it's not relevant to this article how many americans don't believe in global warming". Westwind, I'm afraid global warming is not easily reducible to a soundbite that will be understood by American public opinion. That does not mean, however, that it doesn't exist. There are plenty of scientific theories which are supported by the evidence but not understood by American public opinion. Quantum mechanics implies that quantum cats can be alive and dead at the same time. I'm not sure that's understood by scientists, let alone the American public, but that doesn't make quantum mechanics any less true, as far as we can tell. The article on "Attribution of recent climate change" reflects the fact that attributing climate change to particular causes is quite hard. Explaining exactly what happened to the Earth's atmosphere millions of years ago is also hard. What do you want us to say? It's easy? How exactly would you explain quantum mechanics in one sentence to the American public? Unless you're prepared to become a specialist in the area, and wade through dozens of scientific papers, you're going to have to take a certain amount on trust; i.e. you're going to have to believe the specialists, especially when they essentially all agree. Alternatively, you are at liberty to become a specialist, understand the papers and correct this article where necessary. Wanting something to become simpler to understand, however, ain't gonna make it so. Regardless of what American public opinion does or does not think.--Merlinme (talk) 10:47, 23 October 2009 (UTC)

Merlinme: A Wikipedia article is not a soundbite. If Wikipedia articles can describe things such as Einstein's theory of relativity, then certainly they ought to be able to describe what it is about the current warming that indicates a human cause rather than a natural one. It is quite elitist to say to users of Wikipedia "Global warming is caused by humans, but sorry, you're not smart enough to understand how we know that." Here is the inherent contradiction: You say that "attributing climate change to particular causes is quite hard." If that is true, then why are so many scientists apparently convinced that it is human-caused. It doesn't take a rocket scientist to see that "difficult attribution" and "overwhelming agreement of attribution" are inherently contradictory. This is something the common man can understand. So why leave it out of the Wikipedia article? It only leaves one with the taste of "the emperor has no clothes." I am not saying that the explanation is easy; I am only saying that it is not so difficult that it falls outside the scope of a Wikipedia article. If Wikipedia is simply a matter of "trusting the specialists", then why have an article on relativity at all? Why not just have an entry that says "Relativity -- E = mc2. As to why this is true, just trust the experts." Of course, the article on Relativity says much more than that. So why is it only the global warming articles that refer so often to "all scientific bodies agree" or "because this report said so". Have you ever taken the time to listen to the arguments of those who deny human-caused global warming? My points are precisely what they are saying -- that there is no evidence that the current warming is human caused. So then why would the Wikipedia article stick its head in the sand and refuse to explain why we know the warming is human caused? I am disappointed that you again seem to intentionally misunderstand my point. I don't want attribution of global warming to become simpler to understand; I am saying that, although it may be difficult to understand, it is not so difficult that it should be left out of the article entirely, or passed off to "most scientists agree". I am astounded by the strong resistance that you global warming supporters have to including an explanation in this article of why we know it is human-caused. Your resistance deepens my doubts about whether global warming is indeed human-caused. --Westwind273 (talk) 07:33, 24 October 2009 (UTC)

It doesn't take a rocket scientist to see that "difficult attribution" and "overwhelming agreement of attribution" are inherently contradictory.
Would you say it is easy or difficult to launch a human into space safely? If it is difficult, but there is overwhelming agreement it has been achieved, as there surely is, your claim is that everyone is lying about us having launched thousands of astronauts into space? Difficult and impossible are not synonyms. --86.129.7.162 (talk) 17:53, 28 October 2009 (UTC)

Yes. I am not denying global warming is human caused. I just want the article to explain why we know it is human caused. For example, the article on the Apollo program goes into quite a bit of detail about how it was that we got men to the moon and back, even though it was quite difficult. If Wikipedia can explain the Apollo program in all its complexity, then why can't a Wikipedia article explain clearly why we know that global warming is human caused? It is only the global warming articles that are replete with "because all scientists agree" or "because such and such report says so". --Westwind273 (talk) 02:59, 29 October 2009 (UTC)

We've spent (wasted) rather a lot of time in the past on this article fighting off the wacko septics. They seem to be pretty well gone now, so I'm happy to agree: this article could do with some work along the lines you suggest. I have, you'll have noticed, begun William M. Connolley (talk) 09:19, 29 October 2009 (UTC)
I would personally prefer it if the section on, say, the fingerprint of anthropogenic warming, were clearer. Even if the science is gnarly, I would hope that there's a way of at least explaining the main possibilities to a lay reader. That would improve the article. However, even if that can be done, I doubt it will make Westwind happy. I'm not quite sure what will make Westwind happy. He appears to be implying he understands general relativity, quantum physics and rocket science just fine, but can't read and understand IPCC articles on global warming. On the specific area of rocket science, I'm not sure the analogy with the Apollo programme holds. The Apollo programme is forty year old technology which we know worked. Describing that will always be easier than describing current research on something which is very likely but not certain. --Merlinme (talk) 20:54, 30 October 2009 (UTC)
A point I'd make is that "scientific method" in this subject is little understood, as the complexity of the research loses most people who do not have the patience for science that involves over a dozen different disciplines.Mathematics,geology,physics,solar radiation,thermal energy,biology involving mass consumption of carbon by sea algae,as well as the oceans ability to transmit and change the Earths atmosphere such as the El Nino and La Nina events to name only two.The comparison with the Moon program reminds me that there are Moon landing deniers who take their prejudice and fears of government "conspiracies" into this subject.The steps taken to develope the technology to get to the Moon over the centuries engaged the public with the event. Science and scientific method are not an everyday experience for the general public, yet this climate change research will change all our lives.When science collides with politics always expect the possibility of hysteria and manipulation of information.Ern Malleyscrub (talk) 00:54, 28 November 2009 (UTC)

Here are two web pages which contain the best explanations I've seen yet about why we know the warming is mostly human-caused:

http://www.ucsusa.org/global_warming/science_and_impacts/science/global-warming-faq.html#How_do_we_know_that_humans_are_the_major

http://www.edf.org/documents/5279_GlobalwarmingAttributuion.pdf

I would argue that this is not as complicated as everyone is making it out to be, although I will admit that it is more complicated than I originally supposed. Basically the story boils down to this: We know what causes naturally occuring global warming (increased sun activity, etc). These types of causes are not happening in enough quantity to explain the global warming that has taken place during the 20th century. At the same time, we know that human activity has dramatically increased the amount of CO2 in the atmosphere. Given what we know about how the atmosphere works (the effect of increased CO2, etc), it is overwhelmingly likely (90% probability) that most of the observed global warming in the 20th century was caused by human activity. Quite simply, other known natural causes of global warming are not occuring in enough quantity to account for the observed warming.

I think this article should use more of the concrete wording from the above two websites, along the lines that I just wrote. Just my humble opinion. --Westwind273 (talk) 06:45, 5 December 2009 (UTC)

excuse me Westwind273,added a link same day,laterErn Malleyscrub (talk) 13:01, 5 December 2009 (UTC)

see also IPCC link here http://www.ipcc.ch/publications_and_data/publications_ipcc_fourth_assessment_report_wg1_report_the_physical_science_basis.htm added later Ern Malleyscrub (talk) 12:46, 5 December 2009 (UTC)

My point is that someone should not have to dig through a 100-page IPCC report just to understand the main points of why we know that global warming is human-caused. This "gnosis" attitude of "go read the report" is why so many Americans do not see global warming as a problem. It is correct that truth in Wikipedia articles should not be influenced by how many people believe in that truth. But let me say that Wikipedia exists to serve a societal purpose: the spreading of (hopefully correct) information. As one of the outlets for public education, Wikipedia should have a concern that majority of the public does not believe what appears to be true. And it is altogether fitting and proper that Wikipedia should reflect on itself and see if its own articles are perhaps part of the cause of the public misperception. --Westwind273 (talk) 16:52, 5 December 2009 (UTC)

Redundancy[edit]

Isn't it somewhat redundant to have a section called "Attribution of 20th Century Climate Change" within an article called "Attribution of Recent Climate Change"? After all, isn't this what the whole article is supposed to be about? This seems to be a clever apology for the fact that this article talks about anything but what it is supposed to cover, which is a clear explanation of why we can attribute recent climate change to human causes, not repeated references to "all scientists agree" or "this study concluded". It is so sad that this article is so poorly written, since its topic is one of the most critical of our times. --Westwind273 (talk) 23:42, 24 October 2009 (UTC)

Cheers for that constructive criticism. I'm glad to see you're spending so much time making Wikipedia better, despite the efforts of all the rest of us. --Merlinme (talk) 20:42, 30 October 2009 (UTC)
Thanks Merlinme. Nice to know that my contributions are appreciated.  :) --Westwind273 (talk) 07:04, 16 November 2009 (UTC)

Does this merit inclusion?[edit]

"Recent climate change" is rather vague in my opinion. Given the current obssession with global warming and the nature of the article as dealing primarily with global warming, the definition of "recent" should be something like "from the beginning of the current warming trend" (which, according to even this hockeystick graph, http://en.wikipedia.org/wiki/File:2000_Year_Temperature_Comparison.png, began sometime after 1600 and before 1700, before the Industrial Revolution). In my brief scan of the article, the (relatively) exact DATE of the the inception of the warming trend is not mentioned; it says something about 1750 but that's not what the hockeystick says. I think a discussion on theoretical causes of this pre-industrial warming is warranted. —Preceding unsigned comment added by 69.90.55.168 (talk) 14:49, 17 November 2009 (UTC) Another obscure piece of information is the link of volcanic activity to global temperature variations.The Pinatubo eruption was significant enough to show the effect of stratospheric dust reflecting sunlight and solar energy.This is discussed in the book "Superfreakonomics" with somewhat fanciful ideas about using sulphur to cool the planet(!).Also complicating the subject is the discovery of enormous areas of the Earths oceans that once become de-oxiginated by trillions of tons of algale blooms that thrived and provided oxygen into the atmosphere & ocean then died and sucked up oxygen as they decayed en masse.These dead zones were covered by sediment and were sealed under the surface to be discovered many millenia later when homo sapiens needed oil.Although brief, this wikipedia article provides all the basics.If needed,hundreds of books containing thousand of pages are available.Let's keep wikipedia succinct and brief, if possible.ThanksErn Malleyscrub (talk) 07:02, 22 November 2009 (UTC)

Citation Standards Question[edit]

The first citation in the article points to a page that has dozens of megabytes of reports linked. Is that as close as these footnotes need take the reader? Citing so generally is akin to pointing someone to the library and saying, "the answer's in there somewhere." Can the article's writers do better? And if not, why bother with such citations? (If the writer genuinely went to the cited source for the cited information, then a page citation should not be too hard to include. And I was taught that citing material you did not read is unethical.) Thank you, Pcrh (talk) 22:43, 23 November 2009 (UTC)

This is a Wiki. Feel free to improve the citations. One problem is that older IPCC reports have been on the web in different forms (html, multiple PDF, single PDFs), and page numbers have not always been consistent (or existent). But I agree that sticking to one version and refining the references is a worthy endeavor. If you want to verify a particular statement, though, it's usually pretty fast to search in the document. If you do, please add the page number. And remember, we are all volunteers. With Wikipedia, you get a lot more than what you pay for. --Stephan Schulz (talk) 22:50, 23 November 2009 (UTC)

Bayesian Probability[edit]

This article neglects to attribute the consensus probability specifically to Bayesian probability. The reader would benefit from a distinction made about frequency observed probability vs Bayesian Probabilities. A link to the Bayesian article should be provided. It is impossible to have frequency probability on a single global event, all the research is conducted in the greater Bayesian context. source [4] Which has inherent objective flaws and is subject to rapid changing views. Zulu Papa 5 ☆ (talk) 22:03, 27 November 2009 (UTC)

I don't think the article would benefit from this distinction. The distinction does exist, and can affect interpretation. JEB has some interesting posts on Bayesian stuff and cliamte science, e.g. [5]. But it doesn't appear to be a *notable* topic in the field William M. Connolley (talk) 22:13, 27 November 2009 (UTC)
The subject is taken for granted. I am not saying give the topic undue weight, just fair mention. It likely not very active because their is little to be done about it. It is obvious to me that this is at heart of the debate. Folks are just beginning to measure the consensus changes as scientific study. The Bayesian context is relevant and meaningful to justifying this important issue where there is no realistic proof outside of mind objects. Zulu Papa 5 ☆ (talk) 22:33, 27 November 2009 (UTC)
It may be obvious to you that it is at the heart of the debate, but (to belabour what I hope is the obvious) your opinion doesn't matter; you'll need to bring in some RS's for it William M. Connolley (talk) 22:55, 27 November 2009 (UTC)
You obviously missed the source above [6]. This is adequate to justify Bayesian probability for relevant, notable and meaningful inclusion in the article. (I apologize for misleading you with my opinion.) Again, what should be said with a link (and text) is the probabilities are Bayesian. This is not a synthesis, it's just good editing and is what Wikipedia is about with linking. (My opinion matters as much as yours, thank you.) Zulu Papa 5 ☆ (talk) 23:40, 27 November 2009 (UTC)
A source [7] from IPCC. Zulu Papa 5 ☆ (talk) 23:52, 27 November 2009 (UTC)
You provided a link to an unpublished paper (or to a pre-print of something that was subsequently published? I'm not sure which). What you have proved is that "bayesian ideas have been used in climatology". Since that was never in doubt, you haven't got very far. Your *claim* is that "it is at the heart of the debate" and you have provided no evidence for that. A small section from WG II doesn't help much either. I think it is clear we disagree. I'll back off for a bit and see what others have to say William M. Connolley (talk) 00:08, 28 November 2009 (UTC)
Ok, it's better to follow this source [8] from IPCC. I got to break now too. Zulu Papa 5 ☆ (talk) 00:31, 28 November 2009 (UTC)
Clearly it's not a 90% probability in the same sense that it's a 90% probability that you will roll between 1 and 9 inclusive on a ten sided die. But I would have thought this was (relatively) obvious. Having had a quick look at the links, I'm unconvinced that they would help people understand; I'd have thought there's a high chance they would instead make the article more confusing to read. You make what is a (relatively) intuitive concept and imply that people have to understand quite a technical field before they can understand climate change. People don't need to understand Bayesian probability to understand that the 90% figure is an estimate based on a large number of different factors. It's an opinion, albeit one which has an extremely large degree of support in the scientific community. --Merlinme (talk) 09:06, 3 December 2009 (UTC)

MMGW[edit]

A wikipedia search on 'MMGW' redirected me to this article. But this article doesn't even mention MMGW let alone explain what it means. 20.133.0.13 (talk) 10:53, 4 December 2009 (UTC)

What do you think it means? What were you expecting to find? Assuming it's a global warming related abbreviation, I would guess it's Man Made Global Warming. In which case it should probably redirect to Global Warming rather than here. --Merlinme (talk) 11:18, 4 December 2009 (UTC)
He means http://en.wikipedia.org/w/index.php?title=MMGW&action=history William M. Connolley (talk) 11:31, 4 December 2009 (UTC)
Well sure, but that just redirects to here. It doesn't give any clues as to what it means, or why it redirects here. --Merlinme (talk) 15:19, 4 December 2009 (UTC)
This might be a complete shot in the dark but I guess if 20.133.0.13 knew what MMGW meant, he wouldn't have a need need to look it up in an encyclopedia. The fact that MMGW is complete myth is totally beside the issue. 81.157.131.194 (talk) 15:26, 4 December 2009 (UTC)
Your shot in the dark may well be right, but doesn't help us work out what it's supposed to mean, either. Although if you know it's "complete myth", then presumably you can enlighten us. --Merlinme (talk) 17:11, 4 December 2009 (UTC)
Well I hadn't got a clue which is why I tried to look it up. But then Wikipedia is known for being as much use as a chocolate fireguard - especially in environmental matters. 20.133.0.13 (talk) 10:20, 9 December 2009 (UTC)
  • Fixed by redirecting to AGW, a dab page that includes "Anthropogenic (man-made) global warming." Cheers, Pete Tillman (talk) 22:55, 28 September 2010 (UTC)

Article probation[edit]

Please note that, by a decision of the Wikipedia community, this article and others relating to climate change (broadly construed) has been placed under article probation. Editors making disruptive edits may be blocked temporarily from editing the encyclopedia, or subject to other administrative remedies, according to standards that may be higher than elsewhere on Wikipedia. Please see Wikipedia:General sanctions/Climate change probation for full information and to review the decision. -- ChrisO (talk) 03:01, 2 January 2010 (UTC)


Requested move[edit]

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the move request was: No move. Ucucha 00:51, 25 February 2010 (UTC)



Attribution of recent climate changeAnthropogenic climate change — The title is vague. What is meant by recent? A better title would be Anthropogenic climate change with a redir from the commonly used term Anthropogenic global warming. Article titles should be descriptive, reflect common usage and define boundaries of the topic. -- Alan Liefting (talk) - 04:28, 17 February 2010 (UTC)

Survey[edit]

Feel free to state your position on the renaming proposal by beginning a new line in this section with *'''Support''' or *'''Oppose''', then sign your comment with ~~~~. Since polling is not a substitute for discussion, please explain your reasons, taking into account Wikipedia's policy on article titles.
  • Oppose Is it vague? Especially for an ongoing process? I suppose you could have two separate articles, moving early material into "instrumental temperature record" and later material into a new article "climate change since 1950". The latter title requires the encylopedia user to guess what date Wikipedia editors think relevant, though, unlike "recent climate change". In any case, I really don't like the proposed new title. The main problem is that it assumes that recent climate change is anthropogenic, whereas the IPCC only says it is extremely likely that it is anthropogenic. The other problem is that anthropogenic climate change has probably been occurring since the invention of agriculture, so that title is too broad for this article. Finally, that title already redirects to Global Warming. There would be a case for rationalising the current redirects, it's not clear to me why "anthropogenic climate change" redirects to Global Warming, whereas "anthropogenic global warming" redirects here; but I don't think renaming this article Anthropogenic climate change is the way forward.--Merlinme (talk) 09:08, 17 February 2010 (UTC)
  • Oppose Attribution does not presume/presuppose anthropogenic influences, that there are anthro elements is just the current scientific estimation. If we do a thought experiment where there is a scientific paradigm change, and anthro elements suddenly became minute, then the article would still have merit, since it would then explain how the new distribution of forcings are. The word recent in this case is to separate previous episodes of climate changes from the current period of climate change, there are several reasons for this, most of which aren't related to whether it is anthropogenic or not: The recent period (since the late 19th century) is special by having direct measurements of forcings (as opposed to proxy evidence). Good temporal and spatial distribution of observations on Volcanos, Solar radiation, Clouds, Emissions of gases and aerosols, Topographic data on farmland changes, measurements of temperature, wind .... So: No, it isn't a good idea, and the proposed title is incongruent with the content. --Kim D. Petersen (talk) 15:51, 17 February 2010 (UTC)
  • no - major misunderstanding of the purpose of the article. You need to read it William M. Connolley (talk) 20:44, 17 February 2010 (UTC)
  • Oppose There is nothing vague about 'recent' if you read anything about climate change. Coming at a complex issue from a wide viewpoint and then focussing on specifics is the best way to tackle it. Limiting the title to a current phrase du jour, coined within the denialist movement to try to pick holes, just narrows the initial scope and serves no useful purpose. All the 'AGW' issues are covered, and many more, here and in the other WP climate change/global warming articles. --Nigelj (talk) 18:13, 18 February 2010 (UTC)
  • Support This could correct the Fundamental attribution error since the IPCC mission is human cause focused. Zulu Papa 5 ☆ (talk) 18:19, 18 February 2010 (UTC)
  • Oppose. That the current consensus favors anthropogenic carbon dioxide as the probable major causal factor does not mean that the science is set in stone. Scientific evidence can change, thinking can change, and this article should reflect the prevailing consensus whatever may happen in the future, so the current name, "Attribution of recent climate change", is not broken and doesn't need to be fixed. --TS 16:06, 22 February 2010 (UTC)

Discussion[edit]

Any additional comments:
The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Rv: why[edit]

I reverted CD [9]. Given points 1 and 2 there seems little point adding "and natural" to point 3 William M. Connolley (talk) 20:19, 27 March 2010 (UTC)

EPA ref[edit]

http://epa.gov/climatechange/endangerment/downloads/RTC%20Volume%203.pdf is useful. Its got Mars and all William M. Connolley (talk) 21:15, 9 May 2010 (UTC)

Also the recent RC article http://www.realclimate.org/index.php/archives/2010/05/on-attribution/ William M. Connolley (talk) 11:27, 27 May 2010 (UTC)

Livestock etc.[edit]

The paragraph is clear that the 18% figure refers to anthropogenic emissions, but this isn't obvious in the bullet points – "9% of global carbon dioxide emissions" etc. From this section of the cited document these all refer to anthropogenic emissions, and I've edited accordingly. My browser couldn't find the server for the link in the citations, but a search brought up Livestock's long shadow: environmental issues and options which gives links to sections as well as the complete pdf. Should we change the link in the citation? . . dave souza, talk 07:12, 13 September 2010 (UTC)

Seems reasonable, though its a bit ugly to repeat it thrice. I removed "Scientists attribute..." cos that language always annoys me, its a bit peacocky. Who else could possibly do the attriution anyway? William M. Connolley (talk) 09:03, 13 September 2010 (UTC)

I already posted this on the wikipidia talk page "Climate Change and Agriculture" but it is relevant here as well. This article states that livestock agriculture contributes 18% of greenhouse gases. This seems to come from the article "Livestock's Long Shadow"[1]. However, the EPA states that the production of greenhouse gases by agriculture as a whole is 14% [2]. The wikipedia article on "Livestock's Long Shadow" also notes problems in the the methodology behind the 18% number[3] .

Fingerprinting[edit]

Could we have an expanded and more up to date section on "fingerprinting"? I always thought it was an important part of the attribution, and I believe there's been some recent progress; if I remember correctly there were a couple of big studies in the news which reported that fingerprinting supported an anthropogenic cause. Currently the article is vague as to what fingerprinting actually is, and it seems to point to 2001 reference. --Merlinme (talk) 11:00, 13 September 2010 (UTC)

Would be nice. Its on my list of things to do once peace breaks out again. Though I don't suppose I'll be able to do it then. Never mind, I'm sure one of the inexhaustible supply of experts that arbcomm appears to believe in will suddenly pop up and do it William M. Connolley (talk) 22:49, 28 September 2010 (UTC)
That's a shame. I was considering doing it myself based on news reports and whatever linked research I can dig up, but obviously it would be better coming from a scientist. I'm quite busy at work at the moment, and now my evil Freeholder seems determined to tie me up in legal applications, so I can't really see me having the time in the next month or two. But if and when I have a chance, maybe I'll try to do something and you can correct as necessary. --Merlinme (talk) 07:55, 29 September 2010 (UTC)
I was going to base what I wrote on AR4, which hopefully lays it out clearly. But I haven't checked yet William M. Connolley (talk) 19:57, 29 September 2010 (UTC)

"A Sharp Ocean Chill and 20th Century Climate"[edit]

A new paper [10] in Nature suggests that an abrupt shift in Atlantic sea-surface temperatures around 1970 may offer an alternate explanation for the puzzling "pause" in global warming from about 1940 to 1975. This decline has been conventionally ascribed to the influence of man-made aerosols. The new work suggests that changes in circulation-patterns in the Atlantic, perhaps influenced by the Atlantic Multidecadal Oscillation, may better account for the observed cooling. See When the North Atlantic caught a chill (Nature Science News) and A Sharp Ocean Chill and 20th Century Climate (Andrew Revkin, NY Times) for discussions and speculations. Plenty more in the blogosphere, if you're curious.

This is more a heads-up to work-in-progress, but perhaps our aerosol section here might need a caveat. Interesting work. Best, Pete Tillman (talk) 22:02, 28 September 2010 (UTC)

explanation for the puzzling "pause" in global warming from about 1940 to 1975 - are you sure? It looks like it only talks about ~1970. But as you say, not yet. Let it settle William M. Connolley (talk) 22:47, 28 September 2010 (UTC)
Eduardo Zorita has a nice discussion of this paper at Klimazweibel, and there's lots of chatter in the technical blogs comparing (forex) the 1910-1940 warming to 1970-2000 -- here's one by Judith Curry. Interesting stuff, but way too preliminary for here. Best, Pete Tillman (talk) 20:21, 7 October 2010 (UTC)
Eduardo "Jugula" Zorita? No, I wouldn't call that nice. But even EZ is talking about 1970s, not 1940-70. And Curry isn't talking about this paper, so I'm rather puzzled by your refs William M. Connolley (talk) 20:49, 7 October 2010 (UTC)
What I've been trying to point out, perhaps not very well, is that the scientific attribution of recent climate change is in a state of flux. Pete Tillman (talk) 21:10, 7 October 2010 (UTC)
Oh, now I see what you mean. I think you're rather over-egging your pudding William M. Connolley (talk) 21:27, 7 October 2010 (UTC)

corrected POV "dominant" language not supported by the sources[edit]

Solar activity would have to be considered one of the dominant contributers to the warming, especially if deforestation and black carbon are included. Models do attribute most of the warming to the greenhouse gasses. But the language that previously listed was not only POV but incorrect. The IPCC considers the NET natural contribution to be negative, since it considers the cooling contribution of volcanic aerosols to be greater than the solar warming contribution.--Africangenesis (talk) 11:25, 21 October 2010 (UTC)

Looking at your description of this, it looks like you might be justifying a personal synthesis so I've reverted it now for a more complete explanation. Are you saying the IPCC believes solar forcing to be dominant but does not state so openly? Tasty monster (=TS ) 12:06, 21 October 2010 (UTC)
I doubt "dominant" was an IPCC term. The IPCC will just list a forcing contribution from solar that is in the range of those that this introduction was calling "dominant". Was "dominant" supported by the source for all the entries listed? I notice you did a complete revert, even of things you probably know are correct. How much do you review the sources before doing a revert? When you speculate that I might be justifying a personal synthesis without reviewing the supporting references, are you assuming good faith, or are you engaging in a personal attack? Am I the only one that should assume good faith? --Africangenesis (talk) 12:34, 21 October 2010 (UTC)
A quick look at AR4 didn't turn up the word 'dominant', but the summary here is pretty clear:

How do Human Activities Contribute to Climate Change and How do They Compare with Natural Influences?

Human activities contribute to climate change by causing changes in Earth’s atmosphere in the amounts of greenhouse gases, aerosols (small particles), and cloudiness. The largest known contribution comes from the burning of fossil fuels, which releases carbon dioxide gas to the atmosphere. Greenhouse gases and aerosols affect climate by altering incoming solar radiation and out- going infrared (thermal) radiation that are part of Earth’s energy balance. Changing the atmospheric abundance or properties of these gases and particles can lead to a warming or cooling of the climate system. Since the start of the industrial era (about 1750), the overall effect of human activities on climate has been a warming influence. The human impact on climate during this era greatly exceeds that due to known changes in natural processes, such as solar changes and volcanic eruptions.

(my bolding). Squiddy | (squirt ink?) 12:59, 21 October 2010 (UTC)
They are lumping solar and volcanic together again. Notice that they didn't say solar "or" volcanic. Their listings of the actual radiative forcings have CO2's postive forcing and aerosol's negative (cooling) forcings as the highest, but nothing else is as high as solar or volcanic, certainly the list deforestation isn't.. "dominant" is POV. Please restore the changes. --Africangenesis (talk) 13:17, 21 October 2010 (UTC)
Perhaps the solution is to remove our non-IPCC terminology and see if we agree on whether that resulting statement reflects the source. --TS 13:59, 21 October 2010 (UTC)
Africangenesis, you keep explaining stuff to us, like here what can and cannot get lumped together, but this is no use to us to improve the article. What we need is page-referenced quotes from reliable sources where notable scientists or mathematicians have said that you can't lump these things together, or that you must say 'or' instead of 'and'. No matter how good your explanation gets, it will never help improve the article until we see what you want to say printed in a well-cited, peer-reviewed article. See WP:RS, WP:V and WP:OR. --Nigelj (talk) 14:16, 21 October 2010 (UTC)
Based upon your pattern reverts and comments that miss the point, I agree that it is no use trying to explain things to you, and will explain things for benefit of others instead.--Africangenesis (talk) 19:19, 21 October 2010 (UTC)
We're all here to try to improve the articles, not to explain things to each other. If you have a suggestion to help improve the article, it needs to be backed by verifiable reliable sources. The quality of the sources is much more important than the explanation. --Nigelj (talk) 19:24, 21 October 2010 (UTC)
No you aren't, you are just reverting. You put the feedback article back in a state known to be incorrect and expect me to fix it, presumably because I am so much more knowledgeable. But if you aren't knowledgeable enough to at least leave it in a correct state, perhaps you shouldn't be reverting.--Africangenesis (talk) 19:31, 21 October 2010 (UTC)
OK, now you seem to be getting personal and incivil. Please see WP:CIVIL and the notice re 'Wikipedia general sanctions' at the top of this page. I was trying to be helpful by explaining to you how to put your case more effectively, but as far as I am concerned this conversation is now over. --Nigelj (talk) 20:41, 21 October 2010 (UTC)

Correcting for solar: Known natural forcings would, if anything, be negative over this period.[edit]

How about if we compromise by adding "except solar." to this. We could use the IPCC FAR quote: [4] [4]

--Africangenesis (talk) 22:49, 21 October 2010 (UTC)

Can someone fix the reference please!--Africangenesis (talk) 22:54, 21 October 2010 (UTC)

I don't really understand why you think that quote means we should change the article the way you want us to (or why you think the article is incorrect). The article is saying that the combined effect of all natural forcings over this period is net cooling. The quote you want to use agrees with that. If you think that this could be stated more clearly in the article, then suggest a better wording; but you appear to be under the misapprehension that the article currently is trying to say that "all natural forcings are negative", whereas in fact it is trying to say that the sum of all natural forcings is negative. At no point does it say "solar forcings are negative". --Merlinme (talk) 13:37, 22 October 2010 (UTC)

First source link does not work[edit]

I am redirected to http://guide.opendns.com/main?url=ipcc-wg1.ucar.edu/wg1/wg1-report.html —Preceding unsigned comment added by Jackminardi (talkcontribs) 09:28, 1 December 2010 (UTC)

The website has apparently been taken down, and your DNS provider is lying to you to grab advertising dollars. That, unfortunately, is not infrequent today. I've updated the reference to a proper reference with a link to the official version at the IPCC. And I strongly wish all Webmasters would read Cool URIs don't change. --Stephan Schulz (talk) 12:51, 17 February 2011 (UTC)

Problems at the very first paragraph[edit]

"The dominant mechanisms to which recent climate change has been attributed all result from human activity" Where is the reference? Highly disputable! Solar emmission (not diffusion, not absorption) alone could cause this, yet the evidence is still lacking. This should not be offered as a statement of fact. There is plenty of naysayers still to be found. --71.245.164.83 (talk) 03:12, 17 February 2011 (UTC)

Removed John Christy's view[edit]

I've removed this bit from the opinion section:


Some scientists noted for their somewhat skeptical view of global warming accept that recent climate change is mostly anthropogenic. John Christy has said that he supports the American Geophysical Union (AGU) declaration, and is convinced that human activities are the major cause of the global warming that has been measured.[22]


I don't see that this information is of great importance. If Christy hadn't changed his mind, then it might be worth noting his opinion alongside those of others, like Lindzen. But since he has changed his mind, he's now part of the consensus, and therefore not notable. Enescot (talk) 03:09, 20 May 2011 (UTC)

Added "background" section. Other changes[edit]

I've added a new background section on some key concepts used in the article. I feel that the article should explain these concepts before using them. Ideally these definitions would be integrated into the main article, but I didn't feel up to doing this.

I've removed the picture of per capita GHG emissions. I don't see how this picture is directly relevant to this article. I've replaced it with a picture of rising CO2 levels.

Findings that complicate attribution to CO2[edit]

I've retitled the section "Findings that complicate attribution to CO2" to "Difficulties in attribution". CO2 is not the only GHG. I've also moved the content of this section. The part describing CO2 acting as a feedback is now in a new section called "Earlier climate changes," while the sub-section "Warming on other planets?" is now in the list of scientists opposing global warming consensus article.

I've done this because I felt that the previous revision was not consistent with the IPCC report. As far as I'm aware, the main uncertainty in attribution is distinguishing human activity from internal climate variability. The previous revision of the section could give the impression that the CO2 forcing/feedback issue and "warming on other planets" are the principal scientific uncertainties. I do not think that these issues reflect mainstream scientific thinking in respect of attribution.

I do appreciate why these sections had been included in the way they were. However, I do not think it is appropriate for an encyclopedia article to read like a skeptic's FAQ. Issues discussed in this article should focus on mainstream scientific thinking, and not give undue weight to minority viewpoints. Enescot (talk) 16:26, 14 June 2011 (UTC)

Why on Earth are you moving it to a list of views by specific scientists? Is it a view of a specific scientist? If it should go anywhere then it should be to an article. The controversy article is the one at the top of my mind - but another subarticle might be better. Alternatively remove it completely. --Kim D. Petersen (talk) 16:49, 14 June 2011 (UTC)
I moved it to the list article because Abdusamatov was cited as a source:


Over the last two decades, proxy evidence of local or planetary warming has been observed on Mars,[1] Pluto,[2] Jupiter,[3] and Neptune's largest moon Triton.[4] It has sometimes been asserted in the popular press that this points to a solar explanation for the recent warming on Earth.[5] Physicist Khabibullo Abdusamatov claims that solar variation has caused global warming on Earth,[6] and that the coincident warmings "can only be a straightline consequence of the effect of the one same factor: a long-time change in solar irradiance."[7] This view is not accepted by other scientists. Planetary physicist Colin Wilson responded, "His views are completely at odds with the mainstream scientific opinion," and climate scientist Amato Evan stated, "the idea just isn't supported by the theory or by the observations."[1] Charles Long of Pacific Northwest National Laboratory, who studies radiative transfer, says "That's nuts ... It doesn't make physical sense that that's the case."[8] Jay Pasachoff, an astronomy professor at Williams College, said that Pluto's global warming was "likely not connected with that of the Earth. The major way they could be connected is if the warming was caused by a large increase in sunlight. But the solar constant—the amount of sunlight received each second—is carefully monitored by spacecraft, and we know the Sun's output is much too steady to be changing the temperature of Pluto."[2] Instead, scientific opinion is that these changes are caused by other factors, such as orbital irregularities or (in the case of Mars) changes in albedo as a result of dust storms.[9]


Personally I thought that the list article could be expanded to explain the various non-consensus viewpoints. I'm not a supporter of the controversy article. In my opinion, any controversies regarding particular issues, e.g., climate sensitivity, should be explained in the relevant articles. I don't see why a dedicated article is required.
I'd be happy to restore the section to this article. The reason I moved it was because I thought it would be better placed in the context of other non-consensus viewpoints, e.g., Lindzen. My preference would be to restore the text but retitle the section "non-consensus" or "non-mainstream viewpoints". Since Abdusamatov isn't the only scientist with a non-IPCC viewpoint, an expansion tag might be added to the section as well. Enescot (talk) 19:55, 17 June 2011 (UTC)
I agree with Kim. I've undone the change to the List article. Please either find a better home for it, return it to this article, or give a reasoned argument why it should be removed completely. --Merlinme (talk) 09:02, 15 June 2011 (UTC)
I'm happy to restore it to this article provided that the section is appropriately retitled. I'm aware that the section does take the trouble to make the point that "warming on other planets" is a view that other scientists do not share. However, I feel that this should be further reemphasized by retitling the section (see my response to Kim D. Petersen). Enescot (talk) 19:55, 17 June 2011 (UTC)

Add Portal box|Global warming.[edit]

Add Portal:Global warming. 97.87.29.188 (talk) 19:08, 14 July 2011 (UTC)

Un-Redline ...[edit]

Un-Redline Clim-Past-Discuss.net (Climate of the Past Discussions) please. 99.181.140.243 (talk) 05:08, 15 July 2011 (UTC)

Attribution of 20th Century Climate Change[edit]

This section states, "Over the past five decades there has been a global warming of approximately 0.65 °C (1.17 °F) at the Earth's surface". However, the accompanying graph indicates that the .65 metric is for the past century. One of you special editors should fix that.--184.240.56.237 (talk) 06:19, 16 July 2011 (UTC)

IPCC citations[edit]

The IPCC citations here are woefully incomplete and unspecific. I can't do much about the latter, but in line with Stephan's response to a query two years ago ("This is a Wiki. Feel free to improve the citations.") I shall be replacing the IPCC citations with a revised form, such as now implemented at Global warming. As using {{Harv}} templates will be a lot easier for me, and I think a significant improvement in citations, I query: anyone strongly enough opposed to want to clean all this up themselves? :-) _ J. Johnson (JJ) (talk) 23:41, 14 September 2011 (UTC)

Largely done. Many of the IPCC citations were non-specific, and I have tagged them with "page needed". If anyone is looking for something to do it is quite straightforward to search the indicated source for the particular quote or material, then add the location to the citation in a manner consistent with other citations. This could also be done with several citations of the NAS report (I may come back and build a suitable reference for that). There has also been a start in converting citations to {{Harv}} templates; it is, again, fairly straightforward to move a templated citation/reference from the text to the References section, replacing it with a Harv citation. Ask if you need help. _ J. Johnson (JJ) (talk) 20:49, 26 September 2011 (UTC)

SciAm resource[edit]

Beware Climate Change Risk from A/C, Fridge Gases: U.N. "Soaring use of man-made gases used in refrigerators, air conditioners and fire extinguishers risks speeding up global warming and industry should adopt alternatives, a U.N." Scientific American November 21, 2011 by David Fogarty; excerpt ...

On average, HFCs survive in the atmosphere for 15 years and are about 1,600 times more potent in trapping heat in the air than CO2, underscoring growing alarm about these compounds. Combined with rapidly growing CO2 emissions from fossil fuels, this will make it even harder for mankind to try to limit global warming to 2 degrees Celsius -- a threshold that risks dangerous climate change, scientists say. "In the future, HFC emissions have the potential to become very large. This is primarily due to growing demand in emerging economies and increasing populations," said the report by the United Nations Environment Programme released in Bali, Indonesia. ... HFCs are also used to make insulating foams and aerosols. ... HFCs do not damage the ozone layer, which shields the planet from cancer-causing ultra-violet radiation.

See China, India, Brazil, Montreal Protocol,

97.87.29.188 (talk) 23:56, 21 November 2011 (UTC)

2004 climate change attribution figure is way out of date[edit]

The climate change attribution figure should be removed. It dates back to 2004, and significant diagnostic literature has been published since then that show that models had errors larger than the phenomenon of interest. Stroeve and Scambos described the models as 30 years behind the melting of the Arctic ice cap. Andreas Roesch showed a positive surface albedo bias that amounts to more than 3W/m^2 globally and annually average, and Wentz in the journal Science (2007) showed that none of the models produced even half of the increase in precipitation in the observations. This result was recently confirmed, showing that even the most recent models haven't fixed their under representation of the acceleration of the water cycle.

"The result also suggests that the water cycle is intensifying quickly under global warming—twice as fast as climate models have been predicting."[11]

--Africangenesis (talk) 06:57, 28 September 2012 (UTC)

Which 2004? The one in Non-consensus views? William M. Connolley (talk) 08:02, 28 September 2012 (UTC)
The one that was based on the models later shown to have significant diagnostic issues of course: http://en.wikipedia.org/wiki/File:Climate_Change_Attribution.png --Africangenesis (talk) 08:25, 28 September 2012 (UTC)

An inverse relationship between aerosol levels in the atomosphere and the level of CO2?[edit]

I took this out ([12]) twice.

This is the "Attribution of recent climate change" article, and 100 kyr type changes aren't obviously relevant. As I understand it, the T-dust-CO2 correlation comes from desertification and exposure or sea beds and the like during the depths of the ice age, and that isn't clearly relevant to recent change William M. Connolley (talk) 21:23, 18 October 2012 (UTC)

---

There is no causal relationship inferred by the data or information added. However, the long term data clearly illustrates an inverse relationship between dust(aerosol) and the levels of CO2 and termperature. Long-term data in considering the attribution of RECENT climate change is absolutely necessary for context and the complete absense of it on this page indicates a clear and consistent effort to use it to present a point of view rather than a complete set of facts.

All aspects of climate change are relevant to recent climate change. One person making a determination that long-term change has no relevance to recent change is not acceptable. The effort to keep objective and complete data off of this page makes it a point of view, which is not appropriate.

"Desertification" refers more specifically to land that is transfomed by deforestation and inappropriate agriculture and is irrelevant to the addition of long term data. Mitigation of desertification is done through land reclamation and the introduction of biodiversity, and not related directly to the long term data. Furthermore, with the exposure of sea beds changing over both short and long term it is relevant to both, but since this is only one factor and one thoery, excluding additional data based on it is inappropriate and further serves to present a point of view. Valid data on climate change, even if it doesn't support the point of view of one person, needs to be evaluated objectively, and it's removal makes this article inaccurate and based on edits/removals on the page, largely the opinion of one William M. Connolley.

You were deleting my edits as I was making them. Please be more considerate of new and accurate information, even it you don't agree with the potential conclusions to which it leads readers. The fact that it was being deleted (twice) while I was editing it shows inadequate level of respect for the input of others on this topic.

And with that, I'm hoping you won't delete it a third time.

---Mhannigan (talk) 23:56, 18 October 2012 (UTC)

All aspects of climate change are relevant to recent climate change - no. This is wrong, obviously. And you present no evidence above to suggest it is relevant here. As for "respect" - maybe you should try some yourself? See WP:BRD William M. Connolley (talk) 06:37, 19 October 2012 (UTC)

--- No, William, that statement is correct, obviously. All aspects of climate change are relevant to recent climate change. I did provide more than sufficient reason to include the data. I'm sorry that you don't agree, but that isn't a good enough reason to remove valid data - what is your reason for removing it?

I understand WP:BRD, which you have not followed: "BRD is not an excuse to revert any change more than once. If your reversion is met with another bold effort, then you should consider not reverting, but discussing."

The first thing you stateed was that you reverted my changes "twice". They disappeared AS I was editing - twice. The avoidance of this type of confusion is one of the reasons you should follow it. And certainly the only justification you've provided is that it's "obviously" not relevent. That's not a proper argument. You haven't offered on real reason for reverting the edit - "obviously" isn't a reason. — Preceding unsigned comment added by Mhannigan (talkcontribs) 23:49, 22 October 2012 (UTC)

I will explain again - The short term cannot correctly be considered without the CONTEXT of the larger picture. What you say is not logical. There is no way to attribute short term changes without climate change data that can potentially provide a baseline from which one can determine the short term data that is actually anomylous. Your logic is flawed - if we consider very short term data - say two years - if the two years were alike, we could conclude that climate change doesn't exist on any level and therefore there's nothing to attribute. If the years are vastly different, we could conclude something totally different. However, if we put that in context and found that the temperature was the same every other year for 50 years - average A on the even years, Averag B on the odd, the conclusion is completely different and more meaningful. How can you possibly justify removing the reference data? I think that you bear a bit more burden for explaining why you would REMOVE data that in and of itself does not provide a conclusion of any sort, but which may bear relevance to the topic. What is your evidence that that long term climate change offers absolutely no insight into short term climate change? I would love to know.

Under what situation could you justify removing contextual data in a scientific observation? That seems more "anti-science" and the promotion of a point of view. ---Mhannigan (talk) 23:42, 22 October 2012 (UTC)

--- William - I just saw this link from your user page. You have it linked as "I am famous". http://www.conservapedia.com/William_M._Connolley It reads: William M. Connolley is a British Wikipedia editor known for his fanaticism in promoting the theory of anthropogenic global warming (AGW) and in censoring the views of critics and skeptics. He is the ringleader of the infamous global warming cabal at Wikipedia, a powerful pro-AGW group that has an iron grip on global warming-related articles. Any editors that attempt to introduce factual information that is against their point of view are ceaselessly harassed until they are forced to quit or are banned. Connolley--a Wikipedia editor since 2003--and the group enjoy tacit support from the Wikipedia hierarchy, who often turn a blind eye to the group's misdeeds. This certainly would explain why you are removing factual data.

It has also come to my attention that you are currently under Sanction from Wikepedia regarding reverting changes to Climate Change Related articles?[5] Aren't you currently in violation of those sanctions by doing more of the same? ---Mhannigan (talk) 00:19, 23 October 2012 (UTC)

No, the sanctions have been lifted for non BLP articles. And I would not pay too much attention to attack articles written elsewhere, repeating content from them is not exempt from rules on no personal attacks. Given this dispute is only a few days old before trying mediation why not wait for others to get involved here? I suggest you outline the changes you are proposing on talk first, since the general topic attracts attention, and we can discuss them. --BozMo talk 05:51, 23 October 2012 (UTC)
It's not intended as a personal attack. Nor is it something I wrote. It is quoted because it is linked directly from the users page as "I am famous". At the risk of overuse of the word - this and other factors provide "context" for the issue at hand - the user has a history of removing valid information that doesn't support his position on global warming.Mhannigan (talk) 19:23, 25 October 2012 (UTC)
FWIW reading the content, your addition would not appear to be relevant to the article title and more likely to confuse the reader than help. Presumably this content is somewhere else on WP already? --BozMo talk 05:56, 23 October 2012 (UTC)
Confuse the reader? In what way? By introducing doubt into the conclusion that Global Warming is caused by humans?
Is there any source for the proposed addition? Neither the claim itself nor the relevance seem obvious. Eyeballing the graph, there may be some statistical correlation, but it seems to be a lot more complex than an "inverse relation". --Stephan Schulz (talk) 06:45, 23 October 2012 (UTC)
The source was cited in the proposed content. Of course there is more to the story - it's very complicated. An inverse relation does not address a causal relationship - it merly indicates that there is an inverse relation in the data. And I think we agree - you say there may be some statistical correlation. Because it is complex is not a valid reason for exlcuding it, IMO.Mhannigan (talk) 19:23, 25 October 2012 (UTC)
How far back are you proposing to go in terms of "context"? The climate is a complex system where the long-term is millions or even billions of years; to take this to a deliberately absurd conclusion, the weather we see now presumably is a direct result of the geology and mass of the Earth and its distance from the Sun, however no-one suggests we should go into that in great detail when discussing attribution of recent climate change. Saying "this is relevant to the context" is not sufficient in itself; you have to show why what you are proposing to add is relevant enough to what we are experiencing now to be worth talking about in this article.
What do you mean by no-one suggests we should go into that great detail? No one who? What does No one mean here? No one of the already active editors on this page? I'm suggesting it, so no-one suggests... is no longer accurate. The key word here is "presumably". The long term data, by definition, IS the context. Intentionally eliminating the context is illogical. By this reasoning, let's try to answer your question. What is recent? And where do we draw the line? Using a desired conclusion as a basis for the parameters is bad science. So, what is recent, and can recent data be studied accurately in total isolation? Some Global Warming Advocates choose to use 20 years as recent, some use 50, some use 100. We can change the entire trend to global cooling if we reduce it down to 1 year. The same is true if we 'choose' to study 1940-1950, where the trend reversed for a decade. And you want me to show why it's relevant enough to what we are experiencing now? Self research?Mhannigan (talk) 19:23, 25 October 2012 (UTC)
That is not to say that long-term trends are irrelevant; they may be. Merely saying "this provides context" is not enough though, there is a burden upon you to demonstrate to other editors why what you are proposing to add is relevant to recent climate change. Please make your case here. And please avoid making personal attacks. --Merlinme (talk) 08:33, 23 October 2012 (UTC)
Actually, it was removed because because it is not relevant. Shall I challenge every piece of data on this page by removing it until someone can prove sufficiently to me that it IS relevant.Mhannigan (talk) 19:23, 25 October 2012 (UTC)
  • This seems to be an issue for the #Earlier climate changes section of the article, which itself looks to be in need of revision with more up to date sources. For example, recent studies have investigated the relationship between temperature and CO
    2
    increases at the start of ice ages. Also, why are we citing The Great Global Warming Swindle as though it has any credence? It might work to rewrite this section to appear earlier in the article as context, but it clearly follows after the explanation of forcings. . . dave souza, talk 10:14, 23 October 2012 (UTC) p.s. should we mention the PETM as a comparable earlier abrupt increase in CO
    2
    levels, a comparison made by Hansen? . . dave souza, talk 10:18, 23 October 2012 (UTC)

Note that I put the data in the part of the article that states, With virtual certainty, scientific consensus has attributed various forms of climate change, chiefly cooling effects, to aerosols... My original intention with adding the graph is that it SUPPORTS this existing information. That was my original intention. I didn't expect such a backlash from anthropogenic global warming advocates to supress valid data. Look - the data is accurate, it MAY be relevent to recent changes (it's not up to me to decide that), and I added it to support EXISTING information in the article to make it better. I've never seen/experienced this kind of effort to keep valid, pertinent information out of an article. I don't have a dog in this fight. I was just trying to improve the article. I don't have more time to waste arguing with the anthropogenic global warming advocates that are watching over this page. I can't win here regardless of how important the information is to providing the truth. That's why I started the dispute process and that's where I will have to continue.Mhannigan (talk) 19:23, 25 October 2012 (UTC)

Are you kidding me? Three or four different editors ask you to state your proposal clearly and argue your case, and you write walls of text, treating us if we are all opposing any changes at all, and then say you will be invoking dispute resolution before we've even had a chance to respond? It's not even been clearly demonstrated that there is a dispute, all that's happened is you've decided (without any discussion) that we are The Enemy. WP:NOTBATTLEGROUND springs to mind. Please let us know when you are actually prepared to discuss your proposed changes. Merlinme (talk) 08:03, 26 October 2012 (UTC)
This is my point, right here. I've written "walls" of text explaining why this data belongs here. And as your response indicates, it doesn't matter what I say in support of it. All I get are comments about how I'm not supporting it correctly, that I shouldn't dispute it, etc. Not a single intelligent thing has been said about why the data should not be included. The fact is that the editor who removed my edit while I was writing it has been under sanctions for the exact same thing for the exact same topic. So when a handful of editors that also maintain this page as a POV jump in and side with his inappropriate removal of the information (twice), I'm not very hopeful that there will be an objective evaluation of the very small addition I made to the article which support what is already there. Note that you didn't address that. Note that not a single person has addressed why they don't think it should be there - though there is no shortage of people making personal attacks. If you would like me to take your comments seriously, please relate them to the arguments I've put forward for the inclusion of the data rather than focusing on reasons why my (cited) additions are invalid by default based on process, procedure, etc. Part of "dispute resolution" is "third party opinon" which is the ONLY part of the process that I engaged. And I think it's appropriate, don't you? Enemies? Merlinme, seriously, it would take a great deal more than a discussion on Wikipedia to make you or anyone else here my enemy. At the risk of sounding like a context advocate (made up), let's keep this in context as well. I mean nothing here to be personal in any way and my opinoins have nothing to do with being an ally or enemy of any sort. The immediate and devisive response I saw from my one edit here is not something I have seen before, and I found it unusual enough to persue. The dispute is that I've tried to have discussion, but there has been no real response except to discourage me. I'm not naive. I'm a big boy. If you do have something to say about my proposed addition, and if you'd like to tell me how we can justify considering the short term data in isolation, I'll be happy to hear it. And if you convince me, I will propose different changes to remove all references to long term data. Mhannigan (talk) 22:01, 31 October 2012 (UTC)
I asked you if there is a source for the claimed relationship and its importance. You wrongly claimed that the original addition was sourced - what was there was a description of where the image came from, but no source that either supports your interpretation, nor its relevance for recent climate change. Unless you can bring useful sources, I see no basis for a discussion. --Stephan Schulz (talk) 22:16, 31 October 2012 (UTC)
Please state, briefly: 1) what you want to add or change in the article; 2) how it improves the article; 3) your source or sources for the proposed change. --Merlinme (talk) 08:51, 1 November 2012 (UTC)

Outdated source URL[edit]

Old: http://www.globalchange.gov/publications/reports/scientific-assessments/us-impacts/global-climate-change New: http://academic.evergreen.edu/z/zita/articles/climate/ModernGCC03KarlTrenberth.pdf ?? — Preceding unsigned comment added by Paxik (talkcontribs) 07:21, 9 May 2013 (UTC)

Requested Move[edit]

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section.

The result of the move request was: no move. -- tariqabjotu 06:58, 31 July 2013 (UTC)


Attribution of recent climate changeHow we know humans are causing global warming – It's a lot more direct than the current name, and as such, in my opinion, fits the content better Jinkinson (talk) 13:05, 24 July 2013 (UTC)

While I understand the rationale behind the proposed change, the proposed title rather assumes the answer to the question, does it not? For example, it is entirely possible that some recent climate change could be attributed to natural processes, e.g. solar variation. To hold that position is not incompatible with believing humans are causing global warming, as long as you believe humans are the dominant factor. The current title suggests an attempt to determine how recent climate change has been caused. The proposed title assumes the answer is humans, and even though I believe that is correct, I think it's better for the title to at least allow for the possibility that other factors are involved. --Merlinme (talk) 15:37, 24 July 2013 (UTC)
  • Oppose WP:NOTFAQ Wikipedia is not a FAQ, we shouldn't title articles like it was a FAQ. -- 76.65.128.222 (talk) 06:34, 25 July 2013 (UTC)
The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

Fingerprint Studies[edit]

A study has been performed by P.V. Forster in 2007 that utilises the fact that CO2 emitted from anthropogenic sources such as the burning of fossil fuels and deforestation have a lower average mass number than those emitted from natural sources. The study determines the amount of CO2 in the atmosphere that has been emitted from human sources by measuring the average number of neutrons in atmospheric CO2 molecules. The study conclusively showed that most of the CO2 in the atmosphere was produced by anthropogenic sources. This study was extended by G.J. Bowen and others in 2009, which involved measuring the lateral variation of atmospheric CO2 to determine zones of major CO2 sinks and sources.

I would like to propose that this information is added to the Fingerprint studies section for this page. I have several figures and of course references which can be supplied to support these statements. — Preceding unsigned comment added by Michael Dello-Iacovo (talkcontribs) 11:08, 27 November 2013 (UTC)

You have the wrong page. This one is about attributing observed change to human-released GHG's. There's no doubt at all that the increase in GHG's is human-cuased, so no need for the study you mention.
Technically, your "The study conclusively showed that most of the CO2 in the atmosphere was produced by anthropogenic sources" is wrong, but I think I know what you mean William M. Connolley (talk) 12:48, 27 November 2013 (UTC)

What AR5 says about land-use change[edit]

Land use change has affected CO2 and other greenhouse gasses but is no longer considered a net driver of climate change. This is stated in a number of ways in AR5. Specifically that afforestation has low confidence in mitigating climate change and that land use changes have forcings that offset whatever greenhouse forcings have been created. --DHeyward (talk) 17:27, 9 February 2014 (UTC)

D, as I already pointed out, the talk page guidelines frown on starting new threads to argue the same thing at multiple places. See WP:MULTI. It's ok to cruise related pages to post a pointer back main thread on this issue, however. NewsAndEventsGuy (talk) 18:59, 9 February 2014 (UTC)
These are different statement. GW conflates net effects (wrongly, I might add) of warming. This article states it specifically as a climate driver. This was a change from AR4 to AR5. I thought I'd give editors a chance to read and understand before I made the change and citation. Also, the argument for not changing it was that it could not be cited. It now can. --DHeyward (talk) 20:55, 9 February 2014 (UTC)
OK, but if you don't provide greater detail and the citations you can't assume silence is tacit approval. NewsAndEventsGuy (talk) 21:32, 9 February 2014 (UTC)
From the previous time you brought this up: AR5 WG1 SPM says, in the summary to section B5 (P. 9), "Carbon dioxide concentrations have increased by 40% since pre-industrial times, primarily from fossil fuel emissions and secondarily from net land use change emissions." AR4 says, "Global increases in CO
2
concentrations are due primarily to fossil fuel use, with land-use change providing another significant but smaller contribution."[13] From the un-published body of AR5 we get, "Between 1750 and 2011, the combustion of fossil fuels (coal, gas, oil, and gas flaring) and the production of cement have released 365 ± 30 PgC (1 PgC = 1015 gC) to the atmosphere (Table 6.1; Boden et al., 2011). Land use change activities, mainly deforestation, has released an additional 180 ± 80 PgC (Table 6.1). This carbon released by human activities is called anthropogenic carbon."Section 6.3.1 Does your argument depend on whether CO
2
in the atmosphere is actually a cause of warming? --Nigelj (talk) 21:57, 9 February 2014 (UTC)
Since this is not a WP:FORUM I'm less interested in DHeyward's argument and more interested in the detailed proposals for how to improve the article(s).
The citations are in AR5 and others like here [14]. GHG total emissions in tonnage from 1750 has a large component from land use change (the integral). Currently it is only 10% of emissions. Down from 20% in AR4. In the AR5 Technical summary (page 51, figure TS.4). [15] it is pretty obvious that it is no longer a primary driver for "recent climate change" (i.e. since 1950). There is more as the future RCPs pretty much eliminate land use change as a driver. "In addition, the time evolution of the land use change, and in particular how much was already completed in the reference year 1750, are still debated. Furthermore, land use change causes other modifications that are not radiative but impact the surface temperature, including modifications in the surface roughness, latent heat flux, river runoff and irrigation. These are more uncertain and they are difficult to quantify, but they tend to offset the impact of albedo changes at the global scale. As a consequence, there is low agreement on the sign of the net change in global mean temperature as a result of land use change." (page 55, TS.3.4), That includes GHG emissions (which are rather negligible to concrete and fossil fuels). Land sinks have grown since 1750 just as the ocean has.

"In view of the large spread of model results and incomplete process representation, there is low confidence on the magnitude of modelled future land carbon changes. {6.4.3}"

And Box 1.1, Figure 3. The removal of land use CO2 emissions to compare the older AR4 SRES and AR5 RCP's. It also is trying to compare emission vs. concentration models.

Figure TS.4 though is the definitive emission driven case that land use CO2 is not a driver of recent climate change even thought it is a significant source of GHG's since the industrial revolution (1750 with 0 fossil fuel use). Land carbon sinks are also significant. Albedo and non-forcing effects add even more uncertainty but it's pretty clear land use isn't a significant driver of recent climate change (since 1950) and is not expected to be a significant contributor going forward. --DHeyward (talk) 00:15, 10 February 2014 (UTC) Picture File:Emissions_ar5.jpg

Dopey me. Yes indeed, page 51 Fig TS.4; NewsAndEventsGuy (talk) 08:18, 11 February 2014 (UTC)
Ah ha! Does the picture make sense in terms of what are the current/recent drivers of climate change? This is the hard part because the realities of the science of WMGHG's and their sources don't extend favor to traditional allies but still show fossil fuels and cement as the the main culprit. Planting a tree doesn't do squat in regards to the current problem and some research has stated that trees in certain locations are actually worse. IPCC is never going to tell policy makers to not plant trees but if you google statements by timber industries and environmental orgs you will see press releases that state mid-latitude "forest management" reduces global warming (timber industries) and tropical rainforest preservation and afforestation reduces global warming (environment groups). Both are technically correct but they are fighting for crumbs on that graph. The graph is the "Big Picture" of what and where the problem is and it isn't land use, it's fossil fuels and cement. Make sense or am I missing something? --DHeyward (talk) 11:42, 11 February 2014 (UTC)
Fighting over crumbs, you say? Some folks think we need all the crumbs we can get. Such folk observe that 1 "climate wedge" out of the many that are needed equals ~14 new nuclear power plants, and say we shouldn't sneeze at mitigation efforts that seem puny, because its the net effort that matters.
But more to the point is that we are wikipedia editors. We need to report what the sources say, not interpret them. I still need to look at the TS in detail. NewsAndEventsGuy (talk) 12:39, 11 February 2014 (UTC)
Land-use is not clean energy. Clearly replacing fossil fuel usage is top of the chart (they even put it the top so you can see it). Land use contributions to CO2 today and going forward are declining and largely inconsequential. The "crumbs" aren't small pieces, it's statements that tend to throw a bone at group that has been an ally but is not really relevant any more. Both the timber industry and forest preservation groups claimed vindication with recent IPCC reports. They claimed it over the crumbs of CO2 striving to remain relevant when they are no longer so. Both vie for subsidies to support their industry/views and take money from other mitigation efforts like nuclear/wind/geothermal/solar. So look at the chart again and ask what "policy statements" should be made when the science is viewed objectively? The sources say land use is relatively inconsequential and would not do much of anything even if we reverted 260 years of land-use change to 1750 levels. The sources say dialing back fossil fuels only 30 years to 1990 levels would be HUGE. So do we really want to attribute recent climate change to "land use changes such as deforestation" when the sources show nearly no ROI and most likely a much worse "food insecurity" if that did happen? I like and support tropical rainforest conservation and I like trees but because I like them, I am not simply going to ignore the science and pretend it's a realistic mitigation strategy for climate change nor listen to organizations that get money for promoting those non-scientific views. Those groups get their talking point bone of the integral ("Since 1750, the largest contributors to CO2 are.... So send us money to plant a tree and help save the world from Climate Change.") while they ignore the underlying science. Subsidizing tree farming, rainforest protection or people buying carbon credits by planting a tree to pay for fossil fuel is not mitigation. It's nonscientific, special interest fluffery. --DHeyward (talk) 19:03, 12 February 2014 (UTC)
One climate wedge out of the 15ish that the RSs say are required means building ~15 or so nuclear plants a year and replacing several others. IPCC says land use is 10% of emissions. It wouldn't be hard to standardize those units (climate wedge vs 10% actual emissions). Point is, to offset land use would take a bunch additional nuke plants, and my saying so is for illustration purposes only... the idea is to demonstrate that 10% of total emissions due to land use is still a whopping load of emissions, even if the gross emissions from land use really are less than they used to be. More importantly we don't pass judgments here on what policy statements should be made. Instead we follow sources. Since land use appears in IPCC AR5 WG1's SPM as one of the main emission sources (after fossil fuel and cement manufacture) your claimed expert opinion isn't going to trump that RS, sorry. Even the figure you posted shows IPCC still attributes 10% of emissions to land use changes. And I don't see IPCC saying "stop worrying about land use", nor does any other source you have cited say "stop worrying about land use". Instead we have your spin about what the sources say, e.g., where you interpret them to mean "Land use contributions... going forward are .... largely inconsequential." Show us RSs that say that please because I'm not really interested in your personal predictions. NewsAndEventsGuy (talk) 19:30, 12 February 2014 (UTC)
(Somewhat later) it occurs to me that if you are interested in the efficacy of individual actions of various sorts (e.g. tree-planting), there are plenty of RSs that talk about that subject. Have you considered working on that topic at Climate change mitigation? NewsAndEventsGuy (talk) 00:20, 13 February 2014 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── In an earlier comment in this thread, DHeyward wrote "land use CO2 is not a driver of recent climate change even thought it is a significant source of GHG's since the industrial revolution". However, the sources seem to say that CO2 has a very long lifetime in the atmosphere... if I understand it all correctly, plenty of 1750 CO2 emissions have escaped the various sinks and are still in the air "driving" climate change today. NewsAndEventsGuy (talk) 19:55, 12 February 2014 (UTC)

I never said it wasn't an emission source. I said it's not a driver of recent climate change. Fossil fuels are. Lifetime of CO2 has to do with permanent uptake for sequestration in the long carbon cycle. You can see the bi-annual difference (and diurnal) in the fast carbon cycle in CO2 N Hemisphere respiration in the Keeling curve. There are also carbon dating of atmosphere as living things that respire replenish carbon while fossil fuels and lime do not. Land use change is generally living organic matter already part of the cycle. Fossil fuel and lime sources are not living. One of the "fingerprints" of anthropegenic CO2 is the change in isotope levels due to fossil fuels and lime. And oldie but a goodie is here. The key thing to take away from that is atmospheric carbon cycles back and forth rapidly so no volume of CO2 stays in the atmosphere. Once in the atmospheric cycle of life, carbon dating can be done because of that cycle. In reality, probably 90% the atmospheric carbon "excess" from 1750 is from fossil fuel and lime (cement). They don't even notice radiocarbon footprint (or warming) until 1850 which is expected. If you want simple maths, in the SPM, page 12, land use change added 180 GtC to the atmosphere and land reuptake was 160GtC (so net 20GtC since 1750 - maths not work this way, but okay for BOE). There's 240 GtC of anthropogenic CO2 remaining in the atmosphere. 20GtC out of 240 GtC is roughly 9% (which is the emission percentage). That's exactly the kind of number you'd expect in a rapidly respiring world. Here's another source showing the fraction of carbon that remains in the atmosphere from anthropogenic emissions is relatively constant at 43% (sinks are proportional to emissions as shown on the graph) over short time spans (annual). The fast carbon cycle (up to 100GtC cycled through the system per year) keeps up with emissions at that rate leaving the 43% remainder in the atmosphere. This will tend to force the fractional concentrations from sources to equal their fractional emissions very quickly. What that means is if the emissions from land use are 10%, their fractional component of concentration will be 10% depending on the rate of mixing (100GtC/yr or about 100x the rate of land use emission). Make sense? --DHeyward (talk) 01:58, 13 February 2014 (UTC)
The point here isn't that land-use change emits CO2 (it does). The point is there are no sources that say it's a driver of recent climate change. It's declining in both percentage and tonnage of CO2 emissions and has large error bars and low confidences on net values. Coupled with other land-use change effects, the sources quite clearly say it's around 0 W*m-2. I've pointed that out many times. 0 W*m-2 isn't driving the climate anywhere. Page 13 of the SPM title "Drivers of Climate Change", 10% of 1.68 W*m-2 is about 0.168 offsetting albedo surface changes of 0.15. (I'll the exact "as likely as not" quote I've cited before. ) --DHeyward (talk) 02:29, 13 February 2014 (UTC)

Typo (Page not editable to public)[edit]

Section: "Effect of cosmic rays"

Henrik Svensmark has suggested that the magnetic activity of the sun deflects cosmic rays, and that this may influence the generation of cloud condensation nuclei, and thereby have an ******affect****** on the climate.

(should be "effect")

Fixed, thanks. --Merlinme (talk) 10:43, 3 March 2014 (UTC)

http://royalsociety.org/uploadedFiles/Royal_Society_Content/policy/projects/climate-evidence-causes/climate-change-evidence-causes.pdf[edit]

We can use page 5 William M. Connolley (talk) 21:06, 5 March 2014 (UTC)

Also available as http://royalsociety.org/policy/projects/climate-evidence-causes/question-2/ William M. Connolley (talk) 21:09, 5 March 2014 (UTC)

FYI[edit]

FYI this article was mentioned at Talk:Global warming#Should "Evidence of global warming" really redirect to "Attribution of climate change"? NewsAndEventsGuy (talk) 18:30, 20 March 2014 (UTC)

  1. ^ "Livestock's Long Shadow". 
  2. ^ EPA. "Global Emissions". Retrieved 5 August 2012. 
  3. ^ Wikipedia. "Livestock's Long Shadow". Retrieved 5 August 2012. 
  4. ^ a b Hegerl, Gabriele C.; et al. (2007). "Understanding and Attributing Climate Change" (PDF). Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. IPCC. "Recent estimates indicate a relatively small combined effect of natural forcings on the global mean temperature evolution of the second half of the 20th century, with a small net cooling from the combined effects of solar and volcanic forcings ... In contrast, the direct radiative forcing due to increases in solar irradiance is estimated to be +0.12 (90% range from 0.06 to 0.3) W m–2. ... but over the entire period from 1984 to 2001, surface solar radiation has increased by about 0.16 W m–2 yr–1 on average (Pinker et al., 2005)." 
  5. ^ http://en.wikipedia.org/wiki/Wikipedia:Arbitration/Requests/Case/Climate_change/Evidence