Talk:Causes of climate change

Some POV problems

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

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?

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

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

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

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

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 (talk • contribs)

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

250 years ago?

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

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?

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?

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)

Redundancy

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?

"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.