Talk:Climate change

Important notice: This is the talk page for the article Global warming. Some common points of argument are addressed at Wikipedia's Global Warming FAQ. If you are new to this page please take a moment and have a look at some of the frequently asked questions before starting a new topic of discussion. Also bear in mind that this is not a forum for general discussion about global warming. This page is only to be used for discussing improvements to the Global warming article. Thank you.

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Temperature change of a system

I have been thinking about a good way to make people understand how a few degrees temperature change can greatly effect the viability of a living system. The high specific heat of water acts as a temperature regulator both in the human body and for the earth. The high specific heat of water at 1 calorie per gram per degree Celsius allows for variability in temperature that does not translate completely into raising or lowering the temperature of the water. In other words, in the body, the temperature differential in the atmosphere is taken up in part by breaking water's hydrogen bonds. What energy remains goes to the body's temperature change. This among other regulating systems helps the human body to maintain a 98.6 core temperature when the atmospheric temperature rises or falls. Similarly, the earth's overall temperature is regulated in part by absorption of energy by the oceans' water's hydrogen bonds. Of course if an individuals temperature rises by a few degrees, the individual's entire system experiences great difficulties. Similarly, if the earths' ocean's temperature changes by a few degrees, the entire biosystem will also have great difficulties.

Moreover, as core temperature rises, and we turn more and more to air conditioning and the insulated comfort of powered transportation, there may be another analogy - that of cytokine storm in the body. —Preceding unsigned comment added by 66.94.176.22 (talk) 06:51, 30 August 2008 (UTC)

In my opinion, I think a separate article that explains the effects of global warming would be the ideal place for this. The global warming article itself should be limited to science that is directly related to global warming and not a lecture on the effects.HillChris1234 (talk) 18:15, 25 September 2008 (UTC)

Including Global Warming as a theory vs. fact

In the first sentence of the Global Warming article there is no mention of Global Warming as a theory. The definition of a fact is that it is true if it is undisputed by competent scientists, whereas Global Warming has been disputed for some time now. I propose the first sentence be changed to, "Global warming is a theory that explains an increase in the average measured temperature of the Earth's near-surface air and oceans since the mid-20th century, and its projected continuation." This would best represent the topic. --EchoRevamped (talk) 22:56, 11 September 2008 (UTC)

You confuse the fact of global warming (the temperature has risen significantly since ca. 1900) and the scientific theory that explains global warming via a number of mechanisms, the most significant of which is the anthropogenic increase in atmospheric greenhouse gas concentrations. --Stephan Schulz (talk) 23:02, 11 September 2008 (UTC)

The notion that we should qualify the description of global warming as a mere "theory" sounds remarkably like an anti-evolution rant. The reality is that there is consensus among the scientists who have actually studied the matter. Smptq (talk) 23:06, 11 September 2008 (UTC)

The fact is that the 21st century trend is for cooling of -0.12C/decade, a fact that makes this global warming article shamefully misleading and when the 2008 temperature figures come out you will have no choice but to admit the warming has stopped (barring, that is, an unprecendented rise in temperature in the next few months)Bugsy (talk) 23:15, 30 September 2008 (UTC)

No, you missed my point. Many scientists have the data which prove there hasn't been a significant rise in temperature. I'm not "confusing" the so called belief of "Global Warming" and its scientific theory. I'm saying that Global Warming in its entirety is based on disputed facts and untrustworthy data. These fallacies lead to the belief that Global Warming has lead to a temperature increase, which it hasn't, anthropogenic or not. This is why I believe such a disputed topic should be considered a theory.--EchoRevamped (talk) 03:33, 12 September 2008 (UTC)

I see. If you have any recent and reliable sources denying global warming completely, bring them here. This particular meme mostly stopped after even Spencer and Christy found the warming signal in the satellite data. None of the at least semi-rational sceptic hold the position that the warming does not exist, as far as I know. Anyways, even if you were right (a stretch, but for the sake of argument), the warming itself would still not be a scientific theory. Please read that article. --Stephan Schulz (talk) 07:03, 12 September 2008 (UTC)

The word 'theory' is being used here, and I agree with Smptq that it is also used in Creationist arguments, in the way scientists use the word 'hypothesis'; that is, a pre-experimental, pre-data-collection idea of what might be. Scientific theories have accumulated enough evidence that the original hypothesis has, as far as we mere mortals should be concerned, been proven true. You might also say, 'theories are not theoretical', in the way in which 'theoretical' is commonly (mis-?)used. Scientists are not content with what we take to be sufficient evidence, their standards for evidence are higher, and thus even such proven hypotheses are known as theories. Global warming is either already a theory or well on its way to becoming one, depending on the stringency of required evidence one applies. Anarchangel (talk) 10:17, 30 September 2008 (UTC)

I realize this is a rather fringe opinion, but I feel "global warming" should encompass any kind of warming on any celestial body on a global scale. The article for globe mentions that a globe represents celestial bodies other than Earth, so my interpretation suggests that any warming on Mars, Jupiter, Earth or the Sun would count as "global warming." I believe the science on global warming that is mostly presented in this article should be moved to a separate article on anthropogenic global warming on Earth in the 20th and 21st century. In this light, however, global warming wouldn't be counted as a theory, because it would reference any actual warming that was happening.HillChris1234 (talk) 18:23, 25 September 2008 (UTC)

This article concerns itself with the topic of Global Warming, a term that refers specifically to changes in the climate of Earth. The climates of other planets are treated in their own articles or as part of the main article concerning that particular planet. Mishlai (talk) 08:18, 30 September 2008 (UTC)

There is a war going on between the skeptics and the computer scientists wether global warming is man-made or natural. No one really knows. But preventive measures should be taken none the less. —Preceding unsigned comment added by 72.13.137.7 (talk)

New paper

Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia. Tim Vickers (talk) 23:33, 11 September 2008 (UTC)

Because if there's one person whose temperature reconstructions we can trust, it's Michael E. Mann. Oren0 (talk) 07:09, 12 September 2008 (UTC)

Probably best on the temperature record of the past 1000 years first. And ideally without snide comment William M. Connolley (talk) 07:24, 12 September 2008 (UTC) Adding: also, unless there is something vital in this new paper, I will use my std argument that new papers should be left to settle for "a while". And as far as I can tell, this is being treated by the world in general as "more of the same". None of the skeptics are going to be converted William M. Connolley (talk) 07:47, 12 September 2008 (UTC)

The graph strikes me as unremarkable except the spike on the extreme right, which I guesstimate as the last 20 years. This seems out of whack since satellite date shows global temperature as pretty much stable for 1980-2008. Kauffner (talk) 09:18, 13 September 2008 (UTC)

Humm...monthly temperatures...still, if you "split" the global graph in half you can see how most of the months since 1995 are above the normal while those before are under it. --Seba5618 (talk) 00:18, 26 September 2008 (UTC)

Is global warming a falacy?

Surely 'natural' global warming due geological phenomena is not a fallacy but surely global warming is a great fallacy if anyone think that it is merely consequence of anthropogenic action. Another great fallacy is "fossil fuel" (sic) frequently association with "global warming". Surely there's no fossil fuel. Oil and natural gas are abiotic. Carbon dioxide has little concentration in earth's atmosphere. Methane release in geological time such as PETM (Paleocene Eocene Thermal Maximum is more relevant to cause natural global walrming. Important is preserve fresh water that is life and maintenance of plants, trees, forests, animals in their natural habitats ecc, together use clean fuels. —Preceding unsigned comment added by 189.60.253.88 (talk) 02:59, 18 September 2008 (UTC)

Several of your claims are strongly contradicted by the scientific community. The abiotic origin of oil and gas is distinctly fringe, and no-one claims an abiotic origin for coal. The absolute concentration of CO2 is enough for a considerable climate forcing. If you have any suggestions (with reliable sources) on how to improve the article, please state them. This is not the place to discuss global warming in general. --Stephan Schulz (talk) 06:31, 18 September 2008 (UTC)

<Deleted comment from banned holocaust-denying troll>

No need to shout. And Yahoo News is not a reliable source. It's also not particularly wrong, in this case. Large-scale cattle farming is a contributing to methane emissions and overall greenhouse gas emissions in a non-negligible way. I don't know about your farts, but mine are negligible, as I don't chew the cud in between letting my gut flora ferment all the grass I eat.... --Stephan Schulz (talk) 07:58, 2 October 2008 (UTC)

Not that it matters, but that same comment is available from Aussie MSM sources... im not going to bother fetching a link, but I noted it on either the Herald Sun or Daily Telegraph website Jaimaster (talk) 08:29, 3 October 2008 (UTC)

No warming from 1940 to 2008

Global temperatures are the same as as they were 68 years ago, despite an increase of 800(?)% in human caused CO2 levels. [1] How could this finding be incorporated into the article? ^rossnixon 02:13, 23 September 2008 (UTC)

Given that your source is a blog, and that, as we hopefully all know, mentioning the emission of CO2 is a red herring (the atmospheric concentration is what is relevant), and that the author cannot distinguish weather and climate, and that he pick the most conservative interpretation of the temperature measure that shows the smallest increase in temperature, I would suggest "not at all" unless we can get a proper peer-reviewed paper. --Stephan Schulz (talk) 06:42, 23 September 2008 (UTC)

It is valid to point out that the blog author uses the most conservative sources for his reference, but is it not also valid to point out that this article tends not to cite those conservative sources in favour of land based measurements, the accuracy of which is under sustained attack? Wattsupwith that? :) Jaimaster (talk) 04:25, 26 September 2008 (UTC)

Assessments of the trend in global average temperature take into account a great many factors, including satellite measurements, land surface measurements, oceans surface measurements, weather balloons on so on. There are also secondary indicators of a warming climate, such as sea level rise, melting permafrost, loss of sea-ice extent, and so on. The author cited has cherry picked a data set that serves his purposes, and has neglected to give any treatment to the complexities or differences between surface measurements and satellite measurements of the lower atmosphere. The article further discredits itself by suggesting that Global Cooling is implied. Most of the heat that has been added to the Earth has been absorbed by the surface layers of the ocean, but this is conspicuously not mentioned. Data taken out of context is meaningless. This article speaks to some of the differences between satellite and surface measurements. [2] Even if the troposphere really hadn't warmed, it would be cause for us to reevaluate our understanding of how the atmosphere reacts during a warming event, and not reason to discount every other indicator that the planet has indeed warmed. Mishlai (talk) 05:05, 26 September 2008 (UTC)

Well said. Regarding the troposphere not warming, why is it only cause to re-evaluate our understanding of how the atmosphere reacts to a warming event, and not also cause to re-eveluate our hypothosised causation for that warming event as well? Jaimaster (talk) 08:33, 3 October 2008 (UTC)

Again, I'm not sure the cause of any kind of planetary warming on Earth in the 20th and 21st century has any place in an article on "global warming" in general. Any kind of warming on any planet could count as "global warming," and I feel modern anthropogenic global warming science should be reflected on an article set aside to discuss that particular subject.HillChris1234 (talk) 18:28, 25 September 2008 (UTC)

The terminology and topic of the article is consistent with the way it is used in the media and other sources. Mishlai (talk) 00:09, 2 October 2008 (UTC)

Needs long-term data

The Vostok ice core data is far too short-term (500,000 years). There is a billion years of sedimentary rock and plate tectonic data that can be used to estimate past temperatures at various latitudes over a much longer time frame. Jwray (talk) 06:23, 23 September 2008 (UTC)

Why do we need that? Over much longer periods, very different processes start to dominate, from continental drift to the aging of the sun. Also, of course, the farther back we go, the less reliable the estimates do become. We have a link to Geologic temperature record, which has graphs for the last half billion years. This is not very relevant for the current phenomenon of rapid global warming. --Stephan Schulz (talk) 06:36, 23 September 2008 (UTC)

What evidence do you have that the current rate of warming is unusual even in the context of the Holocene period? Even if you believe Mann's proxy data, that only goes back a few hundred years. Besides, the current rate of warming doesn't appear at all that rapid, we're approaching a decade with no warming at all, or even slight cooling. The late 20th century warming can partly be attributed to the urban heat island effect.[3] How will NASA GISS reconcile themselves with JPL? —Preceding unsigned comment added by 98.207.143.91 (talk) 05:05, 27 September 2008 (UTC)

It's frightening that conclusions such as, "current phenomenon of rapid global warming", could be based on meaningless graphs such as this http://upload.wikimedia.org/wikipedia/commons/c/ca/Holocene_Temperature_Variations.png A series of seemingly random intertwined lines spliced with recent spotty surface temperature measurements pass as science as certain as Newton's laws of motion.—Preceding unsigned comment added by 98.207.143.91 (talk • contribs)

It's a good thing that we have experts for this stuff. I base my opinion on the paleoclimate chapter in the latest IPCC WG1 report and, in a pinch, some of the roughly 300 scientific papers it references. --Stephan Schulz (talk) 08:03, 27 September 2008 (UTC)

Was that a typo Stephan? Perhaps you meant "current phenomenon of rapid global cooling", or "rapid climate change"? ^rossnixon 02:11, 24 September 2008 (UTC)

Read climate and geological time scale. Thanks. --Stephan Schulz (talk) 07:05, 24 September 2008 (UTC)

This is a discussion on improvements to this article. Please leave discussions on this board to scientifically-cited information that can improve the article instead of debating the methods for obtaining that data. We'll leave that to the scientists. Our job here is to report their findings.HillChris1234 (talk) 18:30, 25 September 2008 (UTC)

Scope of "Global"

According to wikipedia, a globe is a spherical representation of any celestial body. So, I wonder if there should be something in this article that mentions global warming could be the warming of any celestial body other than the Earth. I mean, if Mars was warming, wouldn't that count as global warming, too?12.26.68.146 (talk) 18:12, 25 September 2008 (UTC)

• See WP:OR, especially at WP:SYN. Quoth: "A and B, therefore C" is acceptable only if a reliable source has published this argument in relation to the topic of the article Short Brigade Harvester Boris (talk) 18:16, 25 September 2008 (UTC)
• (ec)Composite words very often acquire meaning and connotations beyond their constituents. This is the case with the term global warming, which nearly exclusively is used to refer to the modern episode of fairly rapid global warming. Hence, following WP:NAME, we use the term as it is predominantly used. Also, of course, "global" itself has acquired a meaning quite independent of "globe", as e.g. in the "global maxima of a polynomial". --Stephan Schulz (talk) 18:20, 25 September 2008 (UTC)

Dictionary.com gave me this definition for "global"

• of, pertaining to, or using a terrestrial or celestial globe.

I just believe the true meaning of a word or term should be considered in a factual article and not just what people assume it to mean. Then again, wikipedia is generally an encyclopedia of majority acceptance.HillChris1234 (talk) 18:35, 25 September 2008 (UTC)

Dictionary.com gave me a lot of alternative definitions, including "universal", "comprehensive", "globe-shaped", "of or involving the entire earth". Funnily, it also gave me a lot of definitions of "global warming", all of which mention the Earth, and not one of which referred to "a spherical representation of any celestial body". --Stephan Schulz (talk) 19:15, 25 September 2008 (UTC)

When will this article mention global cooling

It now looks almost inevitable that 2008 is going to be a lot colder than any other year this century confirming the clear cooling trend. Whatever way you look at it, there is no way you can describe the 21st century as "warming". This article is so blatantly lying lying to the reader when it implies time and time again that the world is "currently warming". It is not me that sets the standard, it was the IPCC who proudly announced (in 2001) that the world would warm at between 1.4C-5.8C in the next 110. Since then not only has the world stubbornly failed to warm even at the lowest expected rate in fact it has been cooling (by what would be around -1.4C in the same period). Is there the slightest hint of this in the article? The IPCC has set the standard of the expected range, 1.4-5.8/110 years. Not only is the current trend well below the IPCC minimum (which in itself would deserve a mention), but it is actually cooling not warming. How can any honest person write an article about "global warming" and fail to mention that we are currently experiencing a period of cooling? Just how long does the temperature have to cool before this article will stop bringing the integrity of wikipedia into disrepute? Bugsy (talk) 23:40, 30 September 2008 (UTC)

It has to cool until peer-reviewed reliable sources claim there is a significant climatic cooling trend. Instead, we see a number of publications reinforcing the overall warming trend and warning against misreading the effect of short-term variations as caused e.g. by the strong La Nina effect. --Stephan Schulz (talk) 06:44, 1 October 2008 (UTC)

This user has brought this issue up before; last time it got hijacked into a discussion of what sources are reliable.

Bugsy, (user Isonomia) if you've got a reliable source that claims that the long term trend of warming is over, please bring that here to this talk page and it will get into the article. There is currently this sentence in the climate models section of this article,

In May 2008, it was predicted that "global surface temperature may not increase over the next decade, as natural climate variations in the North Atlantic and tropical Pacific temporarily offset the projected anthropogenic warming", based on the inclusion of ocean temperature observations.[75]

and the leading graph is updated to include the 2007 mean annual temperature. It is quite possible that a well-sourced sentence or two in the "Temperature changes" section mentioning the current short-term trend could improve the section and the article as a whole. However, current reliable sources clearly state that the long-term trend is global warming, so this article should, too. - Enuja (talk) 06:50, 1 October 2008 (UTC)

The problem is mistaking weather for climate change. If the cooler weather of the last half of this decade persists deep into the next, the scientific literature will start reflecting that and question the consensus theory. What does this mean for updating the article in this manner? "Check back in 2015" Jaimaster (talk) 08:42, 3 October 2008 (UTC)

Don't worry. As soon as Obama is elected U.S. president, Gore's "scientific consensus" will admitted that the world really is getting cooler, and that the oceans started to recede at exactly the moment Obama told them to. Kauffner (talk) 09:54, 9 October 2008 (UTC)

So wot is the human contribution to global warming then ?

The first two paragraphs of the introduction to this article are unacceptably logically confused and crucially vague on the central question of what is the human contribution, if any, to global warming, if any ?

It opens:

"Global warming is the increase in the average measured temperature of the Earth's near-surface air and oceans since the mid-20th century, and its projected continuation."

But first, surely global warming is not the specific increase in these temperatures between 1950 and 2008, whatever it may have been, plus the thesis that there will be the same increase in the 58 year period 2008 to 2066 ?

Surely it is just the thesis that there has been an increase since c1950, and that it will continue to increase ?

So surely it should be 'Global warming is the phenomenon of an increasing average measured temperature of the Earth's near-surface air and oceans since the mid-20th century, and its projected continuation.' ?

Secondly, this claim needs a justifying reference that 'global warming' is so tightly defined somewhere or officially as the phenomenon of temperature increase specifically since 1950

Thirdly, instead of then telling us what that specific increase was, rather the article then twofold illogically switches to telling us (i) the increase in the century to 2005 rather than the increase since 1950 as global warming has just been defined, and (ii) only the increase in average global air temperature, apparently excluding the presumably cooler temperatures of the oceans that is included in the opening definition of gliobal warming, as follows:

"The average global air temperature near the Earth's surface increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 100 years ending in 2005.[1]"

But (i) what has the increase been since 1950 that demonstrates global warming as defined here? And (ii) what was the increase in this average when ocean temperatures are included ?

Fourthly, the next sentence then illogically switches back again to discussing a quantitatively unspecified increase since 1950, as follows

"The Intergovernmental Panel on Climate Change (IPCC) concludes "most of the observed increase in globally averaged temperatures since the mid-twentieth century is very likely due to the observed increase in anthropogenic (man-made) greenhouse gas concentrations"[1] via an enhanced greenhouse effect."

But by now we have at least three unspecified quantities X, Y & Z to juggle with, namely

X 'the observed increase in globally averaged temperatures since the mid-twentieth century'

Y 'most of X' Does this just mean more than 50% of X or what ?

Z 'the observed increase in anthropogenic (man-made) greenhouse gas concentrations' But what was this increase in the defined period i.e. since 1950 ?

And in addition to these three unspecified quantities, what specific probability has been put on the 'very likelihood' that most of X is due to Y ? At least 67% or more say ?

And moreover, is this passage claiming that there has been an independent enhanced greenhouse effect in addition to an increase in greenhouse gas concentrations whereby the latter is then amplified further, or only that the greenhouse effect has been increased just because of an increase in anthropogenic greenhouse gas and by no more than that ?

Finally, this also raises the unanswered question of what the increase in total greenhouse gas has been, if any, and thus what the percentage contribution of specifically anthropogenic gases to this increase has been, if any.

In conclusion, this illiterate mystifying waffle surely needs rectifying with some logically clear quantitative scientific analysis on such an important issue, especially given one never learns the answer to this crucial question from the daily media indoctrinal bombardment about global warmng  ?

--Logicus (talk) 18:03, 1 October 2008 (UTC)

See the "terminology" section where references are given for the definition of "global warming." Most of your other questions are addressed later in the text; the lede cannot repeat all of the details given in the body of the article. Short Brigade Harvester Boris (talk) 18:38, 1 October 2008 (UTC)

Surely [82532000 barrels per day] of oil being spewed into the atmosphere has no effect at all eh? Garycompugeek (talk) 19:14, 1 October 2008 (UTC)

Logicus to Boris: Au contraire, none of my questions are answered by the article. But thanks for the reference to the 'Terminology' section, which reveals an even greater thicket of conceptual confusion. For the definition of 'global warming' given in that section is itself notably crucially different from the opening definition, and certainly the references given there do not justify the Wikipedia opening definition of global warming, which is

"Global warming is the increase in the average measured temperature of the Earth's near-surface air and oceans since the mid-20th century, and its projected continuation."

But the Terminoloy sections says:

"The term "global warming" refers to the warming in recent decades and its projected continuation, and implies a human influence.[11][12"

In contrast with the opening definition, this latter definition fails to specify what it is that is warming, and is vaguer about the time period in question and whether it extends as far back as 1950 or not. But more crucially it now only refers to warming in which there has been a human influence, whereby one cannot even sensibly ask the question of whether there has been any human influence on global warming, since on this definition the very notion is of warming in which there is such an influence.

To see further confusion, now turn to the Merriam-Webster Online Dictionary definition of 'global warming' that is given as the justifying reference for the 'Terminology' section's definition, and which is as follows;

"an increase in the earth's atmospheric and oceanic temperatures widely predicted to occur due to an increase in the greenhouse effect resulting especially from pollution."

But this definition does not justify either the opening definition nor that of the Terminology section, for it is crucially different from both at least in the following respects

1) This definition only refers to an increase in temperatures predicted for the future, but not to any past warming as in the two Wikipedia definitions. Thus on this definition we cannot know whether global warming exists until the future.

2) It only refers to whatever portion of warming may be due to the greenhouse effect and especially to pollution, whereas the Wiki definitions refer to the total warming. And it is unclear whether the pollution referred to is purely human, or could include volcanic pollution for example.

But this confusion gets even worse when we turn to the Britannica definition referred to by the Merriam-Webster Dictionary reference, as follows:

"the phenomenon of increasing average air temperatures near the surface of Earth over the past one to two centuries."

This definition crucially differs from the both the Wikipedia and the Merriam-Webster definitions, because [1] it crucially does not include ocean temperatures and [2] it only refers to a past time period and [3] it radically extends the past time period to between one and two centuries, rather than just from 1950.

Now to add further confusion upon confusion upon..., if we turn to the United States Environmental Protection Agency definition given in footnote 12 of the Wikipedia Terminology section definition to justify it, we read:

"In common usage, 'global warming' often refers to the warming that can occur as a result of increased emissions of greenhouse gases from human activities."

So this definition differs yet again from the other definitions at least since it only refers to that warming that results from increased human produced emissions of greenhouse gases and over any period rather than just in some specific period. But contrary to the common usage claim of this definition, most media presentations on global warming separate the notion and fact of warming or not from the issue of its possible causes, such as human activity or not.

Now the practical upshot of this thicket of conceptual confusions is that insofar as any of these five crucially different definitions of 'global warming' permit its quantification, it will surely be different in each case. For example presumably the Britannica definition will generate a different result from the Wikipedia opening definition at least by virtue of (i) not including ocean temperatures and also (ii) in covering two centuries rather than only half a century. And thus the quantification of the proportion of any human contribution to that increase may well be different.

Small wonder then that this highly conceptually confused and confusing article does not give any quantitative answer to the leading question of the global warming moral panic, namely what proportion, if any, of global warming since 1950, or for any recent period, has been caused by humanity. It seems the nearest this article gets to such is in its 'Climate models' section that claims

"the warming since 1975 is dominated by man-made greenhouse gas emissions."

But what does this mean ? Of an unspecified temperature increase of X degrees since 1975, more than X/2 degrees of that increase was caused by anthropogenic greenhouse gas emissions ? So what was the amount of those emissions ? Or rather was the temperature increase caused by an increase in those emissions ? And if so, what was the increase in such emissions in that 33 year period ?

Can Boris or anybody else possibly kindly answer these very basic questions ?

--Logicus (talk) 18:13, 2 October 2008 (UTC)

I think you've noticed by now that no-one is supporting your "logic" (I think you were looking for Mr Logic. Sadly no pictures - maybe thats for the best...). the global warming moral panic essentially reveals your biases. If you're interested in the attribution of change, you want Attribution of recent climate change. If you just want the short answer, its "a bit more than 100%" William M. Connolley (talk) 18:47, 2 October 2008 (UTC)

...eyes...wall of text... Short Brigade Harvester Boris (talk) 18:54, 2 October 2008 (UTC)

Obviously Logicus has issues with the scientific communities consensus of factors creating global warming. Thats fine, however this is not the place to air those grievances. Please bring peered reviewed sources if you wish to add to the article. Thanks. Garycompugeek (talk) 19:16, 2 October 2008 (UTC)

I agree with the verifiability issues raised by Logicus. --Phenylalanine (talk) 03:34, 3 October 2008 (UTC)

Logicus actually raises good points about inconsistencies lead, though they are mostly lost in the essay presentation. More pointedly the twisting between a 1900-present and a 1950-present timescale could be used to show the sympathy of the author lies with anthropogenic causation, through a desire to attribute the full 1900-present warming to industrial pollution without the bother of having to allow for the temparture fall between 1940-1950 within that theory.

Another little inconsistency on the main page - http://en.wikipedia.org/wiki/Image:Global_Warming_Map.jpg (second image on the right) uses relative 1940-1980. Default on the website the image was generated from is 1951-1980, while the most visible often used standard reference is ~1960-1990. Jaimaster (talk) 09:07, 3 October 2008 (UTC)

(undent) The noise in the signal of global average temperature makes a weak trend difficult to detect, so I'm not sure if there's even any agreement on when precisely the warming began. I don't think it makes any sense to assign some arbitrary threshold beyond which we are not concerned. Just saying that "global warming starts at 1950" is absolutely arbitrary. Data will sometimes cover only portions of the relevant period, and - importantly - the closer we get the present the more is known and with more certainty.

Further, since the warming has been observed to accelerate across the last century, analysis of the more recent decades provides a clear indication of the state of warming now.

There's no attempt to avoid the cooling that took place starting in the 40s, this is well understood to be the result of aerosols, and the strength of cooling correlates well with aerosol concentration when compared to the observed cooling effects of Mount Pinatubo. What you do have, if you look at a graph of temperature since 1850 that's at the top of the article, is a point around the middle of the century where the warming becomes quite obvious and temperature manages to climb significantly above the variations that were seen at the beginning of the graph. I think if you look at the warming trend from the beginning of the century until 1940 and then you understand the cooling effect that sulfate aerosols had from stack pollution... it becomes clear that the planet would be warmer yet if not for the effect of aerosols. Far from being something to hide, the aerosol cooling across those decades is a warning that we would have experienced more than a 0.6C increase last century if some of that warming had not been offset by aerosol cooling. Sulfate pollution is regulated now, so we're not going to see the same strength of that cooling effect in the coming century, and even if you tried to use it on purpose the effects of the sulfate aerosols diminishes pretty quickly once you stop emitting them.

For the question way above about "most" - yes, I would say that this means >50% and nothing more specific than that. I don't think this means anything more specific than that in the context of an IPCC statement. If some scientists think it's 90% human, and some think it's 65%, and some think it's 51%, then the statement you can get agreement on is "ok, it's at least half" and everyone can agree, but that doesn't tell us whether it's 51% or 100%, just that it's not 50% or less. I'm unfamiliar with what the range of specific assessments actually are.

In terms of CO2 emissions, this may help answer questions. [4]

I would support changing the introductory language to include the beginning of the century, so long as it doesn't distort what is known into some POV nonsense. Mishlai (talk) 13:38, 3 October 2008 (UTC)

Ecclesiastes 1:9. Short Brigade Harvester Boris (talk) 15:47, 3 October 2008 (UTC)

I have no idea what you intended to communicate by that. Mishlai (talk) 15:59, 3 October 2008 (UTC)

Sorry, I knew what I meant. ;-) "That which has been is that which will be, And that which has been done is that which will be done. So there is nothing new under the sun." In other words, this is not a new point; we've had lots of past discussion on the time frame for global warming as referenced in the first sentence. See the talk page archives/history. The "since the middle of the 20th century" bit is the time frame most in accord with reliable sources such as the IPCC reports. Hope that's clearer... Short Brigade Harvester Boris (talk) 16:09, 3 October 2008 (UTC)

""...is well understood to be the result of aerosols""

Global Warming in a can - Some of the material here has great comedic value. Can't believe you guy's buy this stuff - and just because some hippies with Phd's and a considerable increase in funding since the hysteria tell you so. Independant thought guys, get some. Finalreminder —Preceding unsigned comment added by Finalreminder (talk • contribs) 08:26, 4 October 2008 (UTC)

I respectfully ask that the editor who reverted my edit provide an explanation for this on the talk page. Logicus has explained very clearly that the first sentence in the lead and in the terminology section is not properly verified by the sources provided. My only issue is with verifiability (WP:VER). And I have no POV against global warming as suggested in the revert edit summary, I accept the scientific evidence and I am only looking to improve the article. I hope the more experienced editors here will be able to see to address this issue. --Phenylalanine (talk) 13:18, 5 October 2008 (UTC)

So wot is the human contribution to global warming then ?: Hurrah for one small step of progress in solving the problem I raised, thanks to William Connolley’s helpful referral to the Wiki Attribution of recent climate change article, which reveals a 0.65 °C increase in the five decades to 2004 as follows:

"Over the past five decades there has been a global warming of approximately 0.65 °C (1.17 °F) at the Earth's surface" according to the IPCC's AR4 report mentioned in the historical temperature record article.

The source is IPCC. I therefore put this in the article to replace the current logically misplaced statistic for the last century that opens the second paragraph, thus rendering the first two paras logically coherent.

However, a source is still required for the opening definition. Who or what body has decided contemporary global warming should be dated from the mid-20th century ?

A better alternative here might be just to relax the opening definition by dropping any time period specification in order to provide a completely general definition of GW without restriction to any historical period, which is then only introduced in the second para about contemporary GW. I might do that.

I also flag the Terminology definition of GW as confusing because it is at variance with the opening definition, as are also its references, as detailed above.

I also flag the two opening diagrams as confusing because they are not for the same periods as the text specifies i.e for the last 5 decades, and thus not logically relevant, as Jaimaster has pointed out. Hopefully somebody can provide diagrams that are.

After this initial progress of identifying the amount of global warming since the mid 20th century for this article, to try and provide an answer to the question on which which I first came to consult it, it should surely contain some quantitative statement(s) of the following forms:

1) X% of the global warming of approximately 0.65 °C in the last half century has been caused by a Z% increase in anthropogenic greenhouse gas emissions,

2) X% of the global warming of approximately 0.65 °C in the last half century has been caused by a Y% increase in greenhouse gas concentrations.

3) X% of the global warming of approximately 0.65 °C in the last half century has been caused by a W% increase in the anthropogenic proportion of greenhouse gas concentrations

4) The anthropogenic proportion of greenhouse gases is now V%

Can anybody please fill in the values of the variables V, W, X, Y, & Z in these 4 different global warming propositions, with sources ? Mr Connolley maybe ?

The helpful contribution of Mishlai suggests X can be no more precise than 'at least half' i.e. at least 0.375 °C. Is this so ?

Also thanks to those other few editors who have made helpful and informative contributions, such as Jaimaster etc

--Logicus (talk) 14:31, 5 October 2008 (UTC)

A profusion of articles

Not really the place for it, but lets try anyway. There is:

• Climate change in Texas
• Global warming in Massachusetts
• Category:Climate change in the United States by state lists 5 others

Why just these 7 states? Or better, why these 7 states at all? And Climate change in Nevada isn't on the list. There seems to be a lot of duplication and boilerplate in these articles. Mind you, there is also Category:Climate change in Australia, Climate change in New Zealand, Global warming in India, Global warming in Japan

And Heat pollution could do with some work, or possibly deletion, if anyone is interested.

William M. Connolley (talk) 07:35, 3 October 2008 (UTC)

For starters there aught to be standardisation on names to either GW or CC. The aus article lead ends with an unsourced ad hominem. Ill deal with that on monday... Jaimaster (talk) 09:12, 3 October 2008 (UTC)

Given the name, I would have thought that you can hardly have individual GW articles for only bits of the globe. As to possible effects, i.e. CC, regional articles make more sense but state by state seems a bit OTT. Mikenorton (talk) 09:23, 3 October 2008 (UTC)

Global warming in Massachusetts? What next, global warming in a teapot? or perhaps a nutshell? Kauffner (talk) 10:23, 3 October 2008 (UTC)

There certainly should be an article/s on expected regional climate changes, although climate change by US state is too fine of resolution. How would the article for climate change in Nevada be any different than one for climate change in Arizona? Or New Mexico? If more than one article on regional climate change is needed, by continent would probably afford sufficient resolution. - Atmoz (talk) 15:41, 3 October 2008 (UTC)

Is there a consensus on whether it is good to have this spread of articles by continent/country/state or not? I have been checking for pages or material on global warming or climate change in Africa and not found anything easily. Nor is Africa listed in the banner {{Global warming|state=expanded}}. I cannot find an article on the climate of Africa, never mind change, just a short section here. Or have I missed something?Babakathy (talk) 14:53, 3 October 2008 (UTC)

I don't know. It would be a lot to maintain, and I'm not sure how many good sources we have on specific regions. There's already a great deal of confusion regarding the difference between global trends and regional trends, and I'm also slight concerned that regional articles might add to that. Still, I think that if we have good references then describing the changes in a region could be valuable to some readers. Also, as we learn more and more about the changes it will become too much information for the articles that we presently have. Mishlai (talk) 15:18, 3 October 2008 (UTC)

Note the IPCC reports include chapters on regional climate change in the context of global climate change (Chapter 10 in the TAR, Chapter 11 in AR4). Short Brigade Harvester Boris (talk) 15:33, 3 October 2008 (UTC)

In addition to the IPCC material, there is some literature on Africa, eg by Hulme, Mason, New.Babakathy (talk) 16:00, 3 October 2008 (UTC)

Some of the articles seem to be getting somewhere, such as the ones on Washington and Texas--others, not so much. I don't think there is anything necessarily wrong with describing climate change as it applies to a specific region. However, the article ought to be specific and non-redundant. Best of luck. ~ UBeR (talk) 20:16, 5 October 2008 (UTC)

Mechanism of water vapor feedback

The section on feedbacks discusses the water vapor feedback in a manner that I think leaves the impression that the dominant cause of the additional vapor is that warmer air results in more evaporation because of heat input. It's my understanding that the real effect has more to do with warmer air being able to hold more moisture at a given RH, and that while warmer temperatures certainly add something to evaporation, that for the most part the water is still just evaporating because of sunlight, etc. into air that is capable of holding more. I'm unclear on how %RH is maintained in the atmosphere at conditions less than saturation, so I wanted to ask for some assistance/clarification in making the edit. Mishlai (talk) 04:21, 4 October 2008 (UTC)

Your interpretation "warmer air being able to hold more moisture at a given RH" is basically correct, but I'm having trouble seeing where the current text indicates otherwise. Maybe I'm just not able to see it from a non-specialist's perspective (I assume you're a non-specialist). Give it a whirl and let's work toward something that's clear to everyone. Short Brigade Harvester Boris (talk) 04:25, 4 October 2008 (UTC)

Reworded a bit. Is this better? Short Brigade Harvester Boris (talk) 04:55, 4 October 2008 (UTC)

I like, thank you. It never said anything wrong, exactly, but there was an implication that the cause was more heat = more evaporation. Mishlai (talk) 23:39, 4 October 2008 (UTC)

Newly inserted paragraph

I've removed the following paragraph from the "Feedback" section until it can be discussed and perhaps summarized more succinctly, or otherwise allocated to appropriate places in this and/or other articles:

Recent research carried out in 2008 in the Siberian Arctic has shown millions of tons of methane being released, apparently through perforations in the seabed permafrost, with concentrations in some regions reaching up to 100 times above normal. The excess methane has been detected in localized hotspots in the outfall of the Lena River and the border between the Laptev Sea and the East Siberian Sea. Some melting may be the result of geological heating, but more thawing is believed to be due to the greatly increased volumes of meltwater being discharged from the Siberian rivers flowing north. Current methane release has previously been estimated at 0.5 Mt per year. Shakhova et al (2008) estimate that not less than 1,400 Gt of Carbon is presently locked up as methane and methane hydrates under the Arctic submarine permafrost, and 5-10% of that area is subject to puncturing by open taliks. They conclude that "release of up to 50 Gt of predicted amount of hydrate storage [is] highly possible for abrupt release at any time". That would increase the methane content of the planet's atmosphere by a factor of twelve, equivalent in greenhouse effect to a doubling in the current level of CO₂.

... Kenosis (talk) 05:20, 4 October 2008 (UTC)

I simply added the reference tag, without it you can not see the references and clicking on the numbers does nothing. Q Science (talk) 05:38, 4 October 2008 (UTC)

I think it's good like it is. Mishlai (talk) 23:41, 4 October 2008 (UTC)

The new para was part of this huge edit [5]. I expected to object to any such change :-), but in a quick review didn't find anything problematic. Apart from the para above (a bit too 2008 based), did anyone else review it fully and find it OK? William M. Connolley (talk) 08:29, 5 October 2008 (UTC)

From my examination, the edit noted in the previous comment, while lengthy, appears to be appropriate. --Skyemoor (talk) 09:46, 5 October 2008 (UTC)

After having had a chance to review the paragraph more closely, it does indeed appear to me to be very appropriate to include a slightly more explicit summary about methane in the Feedback section, given the presently accumulating body of literature about the correlation between melting ice and methane discharge. My sense is that it can be summarized much more succinctly so it doesn't clog up the Feedback section with too many specifics, and perhaps allocate the rest of it to, say, Effects of global warming. Also, the statement "That would increase the methane content of the planet's atmosphere by a factor of twelve,", cited to Shakhova et al (2008), appears to me to be a bit premature and speculative. Bottom line: IMO, in this WP article it should be summarized more concisely, using only the more scientifically verified, experimentally replicated material here. ... Kenosis (talk) 13:17, 5 October 2008 (UTC)

Verifiability issues in the lead and terminology section

Logicus has explained very clearly that the first sentence in the lead and the first sentence in the terminology section are not properly verified by the sources provided [6]. My only issue is with verifiability (WP:VER). And I have no POV against global warming as suggested in the revert edit summary, I accept the scientific evidence and I am only looking to improve the article. I hope the more knowledgeable editors here will be able to address this. --Phenylalanine (talk) 20:12, 5 October 2008 (UTC)

Just so it's clear, claims in the lead need not be referenced so long as the same claims are substantiated and referenced later in the body of the article. ~ UBeR (talk)

I agree. Where in the body of the article is first sentence in the lead properly substantiated and referenced? Thank you. --Phenylalanine (talk) 20:22, 5 October 2008 (UTC)

Presently in fn 11 & 12, as well as elsewhere. For further definitions, see also, e.g. these definitions. ... Kenosis (talk) 21:03, 5 October 2008 (UTC)

Thanks Kenosis. Please see this, which demonstrates that footnotes 11 and 12 do not properly verify the first sentence in the lead. --Phenylalanine (talk) 22:04, 5 October 2008 (UTC)

Also, none of these definitions properly verify the definition given in the first sentence of the article lead. --Phenylalanine (talk) 22:45, 5 October 2008 (UTC)

In what way? What specific part of the definition is in dispute? Short Brigade Harvester Boris (talk) 23:11, 5 October 2008 (UTC)

The answer to your question is found here: [7]. --Phenylalanine (talk) 23:23, 5 October 2008 (UTC)

Buried somewhere in there, perhaps. Progress will require a more concise and focused statement. Short Brigade Harvester Boris (talk) 00:15, 6 October 2008 (UTC)

""Global warming is the increase in the average measured temperature of the Earth's near-surface air and oceans since the mid-20th century, and its projected continuation." But the Terminoloy sections says: "The term "global warming" refers to the warming in recent decades and its projected continuation, and implies a human influence.[11][12]" In contrast with the opening definition, this latter definition fails to specify what it is that is warming, and is vaguer about the time period in question and whether it extends as far back as 1950 or not. But more crucially it now only refers to warming in which there has been a human influence, whereby one cannot even sensibly ask the question of whether there has been any human influence on global warming, since on this definition the very notion is of warming in which there is such an influence."

"To see further confusion, now turn to the Merriam-Webster Online Dictionary definition of 'global warming' that is given as the justifying reference for the 'Terminology' section's definition, and which is as follows; "an increase in the earth's atmospheric and oceanic temperatures widely predicted to occur due to an increase in the greenhouse effect resulting especially from pollution." But this definition does not justify either the opening definition nor that of the Terminology section, for it is crucially different from both at least in the following respects 1) This definition only refers to an increase in temperatures predicted for the future, but not to any past warming as in the two Wikipedia definitions. Thus on this definition we cannot know whether global warming exists until the future. 2) It only refers to whatever portion of warming may be due to the greenhouse effect and especially to pollution, whereas the Wiki definitions refer to the total warming. And it is unclear whether the pollution referred to is purely human, or could include volcanic pollution for example."

"But this confusion gets even worse when we turn to the Britannica definition referred to by the Merriam-Webster Dictionary reference, as follows: "the phenomenon of increasing average air temperatures near the surface of Earth over the past one to two centuries." This definition crucially differs from the both the Wikipedia and the Merriam-Webster definitions, because [1] it crucially does not include ocean temperatures and [2] it only refers to a past time period and [3] it radically extends the past time period to between one and two centuries, rather than just from 1950."

"Now to add further confusion upon confusion upon..., if we turn to the United States Environmental Protection Agency definition given in footnote 12 of the Wikipedia Terminology section definition to justify it, we read: "In common usage, 'global warming' often refers to the warming that can occur as a result of increased emissions of greenhouse gases from human activities." So this definition differs yet again from the other definitions at least since it only refers to that warming that results from increased human produced emissions of greenhouse gases and over any period rather than just in some specific period. But contrary to the common usage claim of this definition, most media presentations on global warming separate the notion and fact of warming or not from the issue of its possible causes, such as human activity or not." [8]

--Phenylalanine (talk) 00:30, 6 October 2008 (UTC)

That wasn't exactly a "concise and focuses statement", but let's move on. Given the fact that there are multiple definitions from reputable sources that disagree in one detail or another, what do you propose that we do? Short Brigade Harvester Boris (talk) 02:49, 6 October 2008 (UTC)

Just so it's known, these definitions have been discussed and debated in the past, so I suggest you begin looking for that in the archives. That will give you some sense as to how the precise definition was formulated. What I can tell you is that 1950 is the marker given by the IPCC for which we can contribute most of the warming to man's activities. The article actually points this out for you in the lead. ~ UBeR (talk) 05:10, 6 October 2008 (UTC)

The time frame given in the lead was changed from the prior longstanding language "in recent decades" to "since the mid-twentieth century" here, on 19 March 2008, in response to discussion on talk. The consensus among editors of this article has long been to refer in the lead to the current warming trend, which is the way the words "global warming" are most often used, rather than to refer to historical warming trends generally. ... Kenosis (talk) 16:34, 6 October 2008 (UTC)

Grammatical Mistake

I'm not sure if causes or allows is the correct verb in the sentence, "this warming causes allows the atmosphere to hold still more water vapor" under Forcing and Feedback: Feedback.--Maryrebecca (talk) 01:14, 6 October 2008 (UTC)

Either would be OK. "Allows" is a little more directly linked to the increase in saturation vapor pressure. On the other hand "allows" might be taken as implying the atmosphere can hold more water vapor but doesn't necessarily do so, when in fact it does hold more water vapor (so as to maintain approximately constant relative humidity). But not both. I'll pick "causes," Monty. Short Brigade Harvester Boris (talk) 01:28, 6 October 2008 (UTC)

I thought you weren't allowed to say that the atmos holds WV William M. Connolley (talk) 15:28, 6 October 2008 (UTC)

Comrade Boris say "In Soviet Union, water vapor hold you!" Short Brigade Harvester Boris (talk) 16:12, 6 October 2008 (UTC)

Minor removal of sentence from "terminology" section

I've removed the following sentence from the "terminology" section"

As greenhouse gases increase, the effect is projected to increase.

This was cited to global warming - Definition from the Merriam-Webster Online Dictionary, which defines global warming as "An increase in the earth's atmospheric and oceanic temperatures widely predicted to occur due to an increase in the greenhouse effect resulting especially from pollution." I should think the current version of this article already covers this, but I'm putting it here on Talk just in case it's useful in another section of this or another WP article. ... Kenosis (talk) 03:54, 7 October 2008 (UTC)

There are innumerable verifiable secondary scientific references, as opposed to a less desirable tertiary reference, that refer to projected increases in the earth's temperature. Therefore, limiting the definition to one tertiary reference is not appropriate. --Skyemoor (talk) 16:44, 7 October 2008 (UTC)

Agreed. Though my main reason for removing it was that it was outside of the scope of the section on "Terminology". ... Kenosis (talk) 17:46, 7 October 2008 (UTC)

Does global warming include ocean temperatures or not ?

The article's second sentence currently claims

"The average global air temperature near the Earth's surface increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 100 years ending in 2005."

But this sentence needs clarification in respect of its estimate of global warming ostensibly not including ocean temperatures such as included in the opening definition of global warming, thus possibly inflating the value inasmuch as ocean temperatures are cooler than air temperatures.

It also needs clarification in respect of its estimate being for the last century rather than for the half century specified in the opening definition, thus apparently inflating the value further.

I now repeat this pedagogical point yet again, for the third time, for the extremely hard of understanding and illiterate:

1) The statistic of global warming provided in the second sentence is ostensibly for a different entity than that defined in the opening definition, namely an average for the air only versus an average for air + oceans

2) The statistic of global warming provided in the second sentence is for a different period than that defined in the opening definition.

I replaced this logically irrelevant and possibly misleading sentence with the following sentence that (i) covers the same period as the opening definition of global warming and (ii) which I believe also includes ocean temperatures as in the opening definition of global warming:

"According to the 2004 Fourth Assessment Report of the Intergovernmental Panel on Climate Change, over the past five decades there has been a global warming of approximately 0.65 °C (1.17 °F) at the Earth's surface."

Note that the locution "at the Earth's surface" does not exclude surface ocean temperatures.

But Kenosis deleted it without providing any valid justification or apparently understanding the problem here.

So I therefore restore my proposed sentence and ask Kenosis or anybody else to kindly desist from deleting it yet again without stating some valid justifying reason on this Talk page.

As for the opening definition of global warming, in spite of much blather and also some helpful comments, still no justifying source for this definition has been provided, so I flag it yet again. The reference seems to be IPCC, but where is it ?

--Logicus (talk) 17:54, 7 October 2008 (UTC)

Logicus, I think you've already made your basic POV fairly clear. Whatever your specific content disputes about this article may be, please don't delete important citations from the article. Fortunately, a bot reinserted the citation to the IPCC report.
..... The sentence you removed from the body text of the article was: "The average global air temperature near the Earth's surface increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 100 years ending in 2005.", citing to the same IPCC source as the warming in the "past five decades". As to the consensus choice to include that sentence in the article, it's not at all illogical to note the IPCC's conclusions about climate change over the past hundred years, despite the opening reference to "since the mid-20th century". That's an editorial decision that is a consensus decision, a reasonable one I might add. The choice was made by general consensus of participating WP editors to note at the outset a slightly longer trend of warming that covers the last century, while stopping well short of changing the focus of the entire article from current and projected global warming, a pressing contemporary issue, to a broader generic definition that includes all discernible historical periods of warming that were not anthropogenic. Choosing the latter would result in a completely different focus of the article, and would entail much more discussion of prior non-anthropogenic warming trends going back to the beginning of what can be measured, e.g., from ice core samples. The mention of the temperature trend in the last hundred years in the article is thus by no means logically inconsistent with the use of "global warming" to refer to the trend since the fifties, which is the most commonly used context of the words "global warming" in today's discourse. Rather, the sentence that mentions the warming over the last century is a totally reasonable extension of the chosen scope of this article. So are the graphs and statements in the article that refer to longer periods leading up to the last half century.
..... Having said that, speaking as just one more WP user, I would not in the least be opposed to revising the lead to set the context of the article to include anthropogenic warming going back a century or more. ... Kenosis (talk) 19:54, 7 October 2008 (UTC)

Consensus is not always right, and previous consensus can be changed. Using a 100 year time scale then chopping in the next line to a 50 year time scale when you have a perfectly good 50 year source that illustrates the same point is being inconsistent for the sake of what? I personally see nothing useful being achieved by using the wider reference over the shorter... Jaimaster (talk) 22:44, 7 October 2008 (UTC)

It seems relevant to me to ask whether the article would be harmed by having an introduction that indicates some varying meaning with context? eg: "Global warming refers to increasing global average near-surface temperatures but the precise meaning can depend on context. The most commonly used context implies the warming in recent decades on Earth which many scientific organisations have found to be mostly anthropogenic." Probably a bit woolly but might that be better than being overly precise to the point of being wrong? crandles (talk) 19:44, 8 October 2008 (UTC)

I think we're manufacturing ambiguity. The statement is fine as it is. Mishlai (talk) 04:37, 9 October 2008 (UTC)

Positive Feedback

"The major positive feedback is caused by increased introduction of greenhouse gases into the atmosphere". Evaporation of water vapor, and dethawing of methane hydrates (which are then evaporated) are positive feedbacks. Emissions of fossil fuel burning is not a feedback because they are not induced by warming itself. Was there something else you were referring to that is the 'major positive feedback'? --Skyemoor (talk) 18:01, 7 October 2008 (UTC)

The "Forcing and feedback" section is going downhill at an alarming rate. "The forces that drive climate change are said to be operating in a system called forcing." -- what the...? It gets worse from there. Short Brigade Harvester Boris (talk) 18:45, 7 October 2008 (UTC)

I put that in purely for definitive and introductory purposes, to aid people. I have zero problem with you changing that sentence, if you can think of better wording. Where "it gets worse from there", well, point it out or change it as you wish and we'll see, my mind reading is weak today. Anarchangel (talk) 19:09, 7 October 2008 (UTC)

Do you mean Skyemoor's edits? He took my August is hottest vs Solstice is June analogy out, and maybe some other things, I haven't gotten around to it yet, and was a bit equivocal about the analogy thing anyway. I thought it was good because it was an commonly observable analogy of the principle of the lag between forcing and warming, but bad because it wasn't direct evidence. Anarchangel (talk) 19:15, 7 October 2008 (UTC)

"The major positive feedback is caused by increased introduction of greenhouse gases into the atmosphere". Evaporation of water vapor, and dethawing of methane hydrates (which are then evaporated) are positive feedbacks. Emissions of fossil fuel burning is not a feedback because they are not induced by warming itself. Was there something else you were referring to that is the 'major positive feedback'? --Skyemoor (talk) 13:42, 8 October 2008 (UTC)

As far as I'm aware, we have the albedo effect, the thawing of methane clathrate, the release of methane from thawing of permafrost regions, changes in rain forests that make them drier and more susceptible to catastrophic fire (which would release CO2), the possible decline of phytoplankton in warming waters (microbes that bury a fair bit of carbon when they absorb it through photosynthesis and then die and drift to the bottom), and possibly that organic decay and it's resulting release of gases would progress more quickly at warmer temps.

I think it's self evident that the human burning of oil, wood or coal is not a form of feedback (unless you're trying to make social or economic arguments, which are not the topic of this article). Burning fossil fuels can certainly cause feedbacks, however, and it's also true that the production of greenhouse gases is one of the feedback mechanisms (just not from fossil fuels). I don't see anything wrong with the statement "The major positive feedback is caused by increased introduction of greenhouse gases into the atmosphere" Mishlai (talk) 17:46, 8 October 2008 (UTC)

Good response, these points should be in the article; anyone have any problems with me adding them? --Skyemoor (talk) 10:39, 9 October 2008 (UTC)

IMO, that section should have a brief statement in the first summary paragraph to the effect that the primary positive feedback involves an increase in GHGs caused by warming itself. I understand it may be delicate, but I'm sure there's a way to do it to make it clear to the reader it involves a loop of sorts. As it stands now, the summary paragraph appears to imply that negative feedback is offsetting anthropogenic warming, which it is not. Additionally, it's now clear to me that at some point it'll need a brief statement about methane/permafrost as well, something like a concise version of what Short Brigade Harvester Boris put in a week or so ago. ... Kenosis (talk) 12:43, 9 October 2008 (UTC)

"the primary positive feedback involves an increase in GHGs caused by warming itself" -- assuming this means water vapor acting as GHG it's true but too vague, as it could be interpreted to mean other GHG. Why not simply say that the primary positive feedback is the water vapor feedback? Short Brigade Harvester Boris (talk) 16:35, 9 October 2008 (UTC)

That might help to avoid confusion. ... Kenosis (talk) 17:15, 9 October 2008 (UTC)

OK, got it covered here. ... Kenosis (talk) 18:29, 9 October 2008 (UTC)

So why is land temperature excluded from the opening definition?

The opening definition of 'global warming' states

"Global warming is the increase in the average measured temperature of the Earth's near-surface air and oceans since the mid-20th century, and its projected continuation."

Presumably ‘near-surface air and oceans’ means 'the near-surface air and near-surface ocean temperatures' , with the qualifier 'near-surface' being distributed over both 'air' and 'oceans', as in 'near-surface (air and oceans)' to use algebraic bracketing, rather than just over 'air'. I presume so because I presume it is practically impossible to get an average temperature for the whole volume of the Pacific Ocean, for example, right to its very bottom, and that only near-surface temperature measurement is practically possible.

So it seems we have four categories to consider in understanding the opening definition of 'global warming', namely

(1) near-surface air temperatures above the land

(2) near-surface air temperatures above oceans ( or above all seas or even any water, including lakes) ?

(3) near-surface land temperatures

(4) near-surface ocean temperatures (or of all seas or even of any water, including lakes ?)

So the question now arises for the opening definition of why near-surface ocean temperatures are included in the measurement along with near-surface air temperatures over both land and sea, but near-surface land temperatures apparently excluded from it ?

So who is it that defines global warming as a warming of the average of near-surface air temperatures across both land and sea and near-surface ocean temperatures, but excluding near-surface land temperatures ?

This apparently bizarre definition surely need some scientifically authoritative source to be quoted to ensure us that it is indeed this specific measurement and the warming (or not) of these three specific entities the scientific debate and this article is concerned with.

Is this the IPCC definition of what specific temperatures the global warming issue is to be concerned with ? If so where is it to be found ?

Thus yet again I flag this opening definition for a citation, and one which justifies its exclusion of land temperatures.

--Logicus (talk) 18:08, 8 October 2008 (UTC)

Your presumption is wrong. "Land temperatures" are not a useful concept in this context, as "land" is extremely diverse, and neither well-mixed, well-behaved, or even well-defined. --Stephan Schulz (talk) 18:57, 8 October 2008 (UTC)

The temperature of the land gets significantly hotter and colder than the temperature of the air 10 or 20 feet above the land. Therefore, temperature measurements are made in boxes some distance above the ground. For the oceans, buoys and satellites measure the water temperature, not the air. As a result, there is a lot of uncertainty about the actual average temperature, but much less disagreement about the change in temperature. This is because the measurement techniques are consistent. Q Science (talk) 22:40, 8 October 2008 (UTC)

Logicus comments on replies:

To Stephan: No, rather it seems that both of my two presumptions stated were indeed correct. And your further observations imply land temperatures are indeed excluded from the measure, which therefore answers my question. Thank you ! [Are you saying my presumption that ocean temperatures are near-surface temperatures is wrong, and wrong because it is the temperature of the wholy body of water ?--Logicus (talk) 16:09, 10 October 2008 (UTC)]

To Q Science: You seem to imply near surface air temperatures over oceans are not included, and hence whereby the opening definition is false, and together in consideration of Stephan's comments, should rather say 'near surface air temperatures over land and near surface ocean temperatures'. Would you agree ? Thus we should have something of the following ilk for the opening definition:

‘Global warming is an increase in the average measured temperature of the Earth's near-surface air temperatures over land and near-surface ocean temperatures...’

If this is correct in this respect, then the next question that arises is why the near surface temperatures of seas, lakes and rivers are not included. Should 'oceans' perhaps be replaced by 'marine' or 'seas' at the very least ?

And thanks for your information. I must say I see no valid reason in the points you make for excluding land temperatures, and also it is difficult, prima facie, to see how there can possibly be less disagreement about changes in average termperature than there is about what the average is itself ? But thanks again!

--Logicus (talk) 18:16, 9 October 2008 (UTC)

I think the lead sentence should be very general, even if it is not 100% correct, and the details should be placed in other sections. For instance, the points you want to make appear to be covered in Instrumental temperature record. What bothers me about the definition are the lack of the word theory and the inclusion of a time frame, which imply (to me) that this is a political definition. The IPCC definition actually refers to the increase in temperature caused by people. At any rate, the lead section should represent general usage of the phrase, even if it is scientifically incorrect, and arguing the science should be else where. Q Science (talk) 19:27, 9 October 2008 (UTC)

Logicus to Q Science: Thanks ! Could you possibly please kindly say what that IPCC definition of global warming is by quoting it and where exactly it is to be found ?

I went to the effort to put a link to the definition in my response. Why don't you click on it? Q Science (talk) 17:13, 10 October 2008 (UTC)

I suspect clickoreadophobia. Symptoms include being unable to click a link and read its contents because of the fear the Algore will eat you. Logicus has demonstrated repeatedly that he will not read the references cited in the article before commenting on them. [9] [10] [11] - Atmoz (talk) 17:34, 10 October 2008 (UTC)

Presumably the increase in temperature caused by people is quite different from and less than the 0.65 °C increase in temperature of 'the last half century' ? Do you know what the difference is ? This simple issue seems very confused.

Also I am not aware of wanting to make any points other than ensuring pedagogical conceptual clarification of the current confusion and also getting some simple consistent answers to the basic questions of what warming has been and what anthropogenic greenhouse gas increases there have been, etc.

So could you kindly please specify what points you think I want to make that appear in the 'Instrumental temperature record' article ? --Logicus (talk) 16:09, 10 October 2008 (UTC)

It's my understanding that the precise percentage of human contribution has significant uncertainty brackets as well as some disagreement. The article makes reference to what is verifiable by citing reliable sources, which is the consensus position that this percentage is "most" of the observed warming. It's important to not be more specific than sources can support, because that would be false certainty and intellectual fraud. I suspect if you read the relevant peer reviewed literature you would find some varying estimates.

I also don't think it's reasonable for you to ask other editors to do your research for you. The reference that Q Science provided to you has a definition of "Global Warming" in it's glossary that is easily found by either

• Going to the glossary and following the alphabetical order down to "Global warming or...
• Searching the PDF for "Global Warming." There are about 10 hits. It won't take long to find the one you're looking for.

Your unwillingness to exert these minimal efforts leads me to believe that you are here to create a disruption, and not to improve the article. If you don't feel like you know much about the topic, then perhaps it would be wise to edit a different article? Mishlai (talk) 20:52, 10 October 2008 (UTC)

Why are ocean temperatures excluded from the article's second statement?

This statement claims

"The average global air temperature near the Earth's surface increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 100 years ending in 2005."[My emboldening]

Why does this IPCC statement of global warming for the last century omit near-surface ocean temperatures ? Does its estimate include them, as they are included in the opening definition, or not ? Thus I tag it for clarification or rewrite needed.

--Logicus (talk) 18:15, 8 October 2008 (UTC)

See e.g., [12] and [13]. Short Brigade Harvester Boris (talk) 18:54, 8 October 2008 (UTC)

Logicus to Boris: Thanks for these two references, Boris. If you have read them in spite of your reading difficulties with extended analyses, no doubt with such as Lenin’s Collected Works for example, then I hope you will agree with me that they both seem to testify that the relevant temperatures for determining global warming are taken to be those of (i) the air over land near its surface and (ii) near surface marine temperatures, rather than "global air temperature near the Earth's surface" specified in this statement, which apparently refers just to 'all temperatures of the air over both land and water globally just near their surfaces', thus including super marine air temperatures, contrary to your two references, and excluding near surface sub marine temperatures, again contrary to your two references.

Thus the logical conclusion is that this statement

"The average global AIR temperature near the Earth's surface increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 100 years ending in 2005."

is logically irrelevant information to the issue of identifying what global warming has been as defined in the opening definition of this article, namely

"Global warming is the increase in the average measured temperature of the Earth's near-surface air AND OCEANS since the mid-20th century, and its projected continuation."

namely at least by virtue of omitting near surface ocean temperatures.

And the further questions arises of whether this statement for the last century is even true, if indeed air temperatures near the Earth's surface globally have ever been measured, or is even possibly undecided and undecidable because this temperature is unknown if near surface air temperatures over all water globally (i.e. over oceans, seas, lakes and rivers etc) have never been measured, which I understand may indeed be the case.

So I propose yet again this twofold logically irrelevant and misleading statement should be replaced by an alternative of the ilk I proposed before in an effort to begin reducing the current thickets of conceptual confusion in this appallingly confused and confusing article.

It was as follows:

"According to the 2004 Fourth Assessment Report of the Intergovernmental Panel on Climate Change, over the past five decades there has been a global warming of approximately 0.65 °C (1.17 °F)."

I also note you have said above in recognition of my pointing out the multiple conflicting and thus confusing conceptions of global warming in this article:

“Given the fact that there are multiple definitions from reputable sources that disagree in one detail or another, what do you propose that we do? Short Brigade Harvester Boris (talk) 02:49, 6 October 2008 (UTC) “

What I am proposing is the article be standardised with some simple, uncontroversial and adequate general definition of global warming that is consistently adhered to throughout the article to eliminate its confusingly repeated concept-shifting, such as the one I proposed, but which was rejected without any valid objections in my view.

It was

‘Global warming is an increase in the average measured temperature of the Earth's near-surface air and oceans.’

but in the light of subsequent information should probably now be

‘Global warming is an increase in the average measured temperature of the Earth's near-surface air temperatures over land and near-surface ocean temperatures.’

Here I leave aside the further question of whether it should be ‘marine’ rather than ‘ocean’ to at least include all seas.

--Logicus (talk) 17:58, 9 October 2008 (UTC)

Actually, the "2004 Fourth Assessment Report" was a mistake. The Fourth IPCC Assessment Report is "Climate Change 2007" ... Kenosis (talk) 18:37, 9 October 2008 (UTC)

Logicus to Kenosis: Thanks ! Can I take it you would then agree to the following replacement for the unacceptable current second sentence that confusingly quotes warming for both a different entity and a different period rather than for those specified in the opening definition of warming ?:

"According to the 2007 Fourth Assessment Report of the Intergovernmental Panel on Climate Change, over the past five decades there has been a global warming of approximately 0.65 °C (1.17 °F)."

Can you confirm this claim refers to both near land surface air temperatures and near surface ocean temperatures, rather than excluding the latter ? I believe it does.

And is the five decades in question the period 1957-2007, or some other ?

--Logicus (talk) 16:01, 10 October 2008 (UTC)

Here's a novel idea: actually read some references for yourself, such as the IPCC Working Group I Summary for Policymakers, instead of simply disputing everything based on personal conjecture. Short Brigade Harvester Boris (talk) 16:47, 10 October 2008 (UTC)

'So wot is the human contribution to global warming then: 2 ?'

Logicus copies here what was originally posted as a query to Mr? Connolley on his User Talk page, but since it was turned into an open discussion by others, it ought to be posted here. As follows:

So wot is the human contribution to global warming then ?

Dear Mr Connolley

I would be most grateful if you could kindly provide me with any scientifically accepted values to the variables V, W, X, Y, & Z in the following propositions, as I have already requested of anybody in Talk: Global Warming:

1) X% of the global warming of approximately 0.65 °C in the last half century has been caused by a Z% increase in anthropogenic greenhouse gas emissions,

2) X% of the global warming of approximately 0.65 °C in the last half century has been caused by a Y% increase in greenhouse gas concentrations.

3) X% of the global warming of approximately 0.65 °C in the last half century has been caused by a W% increase in the anthropogenic proportion of greenhouse gas concentrations

4) The anthropogenic proportion of greenhouse gases is now V%

As you may appreciate, the unfortunate impression created by the current Wiki article on GW is that nobody really has a scientific precise quantitative clue what the human contribution to global warming is, which surely cannot be the case.

Best Regards

--Logicus (talk) 18:15, 7 October 2008 (UTC)

Perhaps you should read up on this instead? Your questions 1-3 are the same one (Z=Y=W). Since the increase in GHG's can be attributed ~100% to humans. As for #4 try comparing the pre-industrial levels with the current levels - and you can figure it out for yourself. --Kim D. Petersen (talk) 22:00, 7 October 2008 (UTC)

Actually the proportion of the GHG increase attributable to human activity is more like 230% (i.e., the airborne fraction is around 0.43). Short Brigade Harvester Boris (talk) 22:08, 7 October 2008 (UTC)

Actually - perhaps not? Per [20] "Natural land and ocean CO2 sinks have removed 54% (or 4.8 PgC per year) of all CO2 emitted from human activities during the period 2000-2007." 57% or 54% depends on timeframe and I suspect lower now but I have no issue with the precise figure. If this removal is in response to anthropogenic emissions, doesn't this natural removal get allocated as an anthropogenic effect? I think Williams slightly over 100% is correct based on solar and volcanic forcings being to have a slight cooling effect. crandles (talk) 20:17, 8 October 2008 (UTC)

At risk of being stripped of my science credentials, possibly being shot by the side of the road by the National Academy of Sciences (thereby preventing me from ever becoming a member, sadly), exactly how can we test, let alone prove, that humans have any effect on the weather? I understand the data, but the world was warmer 2000 years ago, and there are what 100X more humans on the planet than there were then? Logicus (who needs to quit using words as if he were mobile texting) asks questions that I'd love to have answered. OrangeMarlin Talk• Contributions 22:27, 7 October 2008 (UTC)

Which data sets are you drawing from that lead you to believe the Earth was warmer 2000 years ago? -_Skyemoor (talk) 13:27, 8 October 2008 (UTC)

Remember your basic calculus? Velocity, acceleration, and changes in rate of acceleration? This would have something to do with 1) an unprecedented acceleration of warming in an already very warm period; 2) CO2 and CH4 levels, which are known to be closely correlated with imminent rises in temperature, levels unmatched since in something like 125,000 years; and 3) unprecedented acceleration of increase in CO2, and likely in CH4 levels. ... Kenosis (talk) 23:49, 7 October 2008 (UTC)

I suspect there is a common misconception that atmospheric models are constructed by fitting historical records and extrapolating into the future. They aren't. Instead they combine the physics of radiative transfer, thermodynamics, and fluid dynamics, the basics of which were worked out decades or centuries ago. Historical rates of temperature change aren't directly used to predict the future (albeit past observations are useful for testing and refining our computational methods by "predicting the past" so to speak). As an aside I don't think we should be using William's talk page for chat and tutorial, though I suppose I just did. Short Brigade Harvester Boris (talk) 01:10, 8 October 2008 (UTC)

Indeed you did.  ;-) Nice explanation; thanks. I'm outta here. ... Kenosis (talk) 00:14, 9 October 2008 (UTC)

Don't worry, carefully vetting guests are welcome William M. Connolley (talk) 07:10, 9 October 2008 (UTC)

Ouch. I guess my highly scientific pee theory isn't welcome then. sad puppy KillerChihuahua?!? 15:11, 9 October 2008 (UTC)

Oops. I meant vetted, not vetting. As a well-behaved puppy I'm sure you've been properly vetted :-) William M. Connolley (talk) 07:26, 10 October 2008 (UTC)

Its Magic Pee. That's what causes the warming. Really. KillerChihuahua?!? 22:30, 7 October 2008 (UTC)

Dear Logicus, you are clearly a person who values precision! This is indeed welcome; I applaud your attitude. But alas, you are falling well below your own high standards, a failing which I cannot doubt you deplore now that you are aware of it. I can help you though: you have erred in my title: I will embarass you no further until you have corrected your oversight William M. Connolley (talk) 08:07, 8 October 2008 (UTC)

---

Logicus to Mr? Connolley: My apologies for getting your title wrong, if indeed I did so. But what is it ? Mrs Connolley, Master Connolley, Lord Connolley, Dr Connolley, Professor Connolley, Great Helmsman Connolley, Scientific Officer Connolley etc ? Please enlighten me that you may further enlighten me with answers to these basic questions. Please note, and also Boris, that a proportion of an increase cannot logically be more than 100% of the increase. --Logicus (talk) 16:26, 10 October 2008 (UTC)