Talk:Climate change/Archive 17

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Archive 10

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Archive 15

Split article? Article needs work

I think that perhaps the article should be split into "human-caused" global warming and just global warming, whereas this article could just mention anthropogenic causes as a possible cause. Even if most GW is anthropogenic, some might be natural. Global warming as a statement is merely an observation that the earth is getting warmer. Also, some parts of the article act as if certain "facts" are completely indisputed. Anyway, just a suggestion. --Rotten 08:29, 29 October 2006 (UTC)

Climate change in general is already discussed in the same titled article. Most people refering to global warming today are referring to the current man-made crisis. Also, some parts of the article act as if certain "facts" are completely indisputed. - fine, identify and suggest modifications. --Michael Johnson 09:28, 29 October 2006 (UTC)

Done! Thanks!--Rotten 09:38, 29 October 2006 (UTC)

As I suspected, pointless. I ain't even a denier, but the article is crap. Now clearly the article says "The prevailing scientific opinion on climate change is that "most of the warming observed over the last 50 years is attributable to human activities"[1].". So I write in the next paragraph, "according to this opinion...". This is reverted withint seconds by the resident psycho-"admin" (which just shows that not all Wikipedian article should be used for any serious work). This article is crap crap crap... yet it could be a much more thourough honest and powerful piece, if you could scrape off some of the nutcases (like a certain "admin").--Rotten 09:51, 29 October 2006 (UTC)

Rv. No thanks. We don't need "according to this opinion" to prefix The increased amounts of carbon dioxide (CO2) and other greenhouse gases (GHGs) are the primary causes of the human-induced component of warming. Read the statement. The idea that CO2 etc are the primary cause of *human-induced* GW is not controversial William M. Connolley 09:47, 29 October 2006 (UTC)

It says it's an opinion in the preceding sentence. Duh.--Rotten 09:52, 29 October 2006 (UTC)

Read it more carefully. Its talking about something different William M. Connolley 10:12, 29 October 2006 (UTC)

What's the point? Clearly Lord God-King William M. Connolley III Esquire won't tolerate dissent on this article whatsoever. ;) Cheers and good night. --Rotten 10:23, 29 October

2006 (UTC)

You follow the usual pattern - make unresonable changes that show you haven't read the article, get offended and offenseive, and leave William M. Connolley 10:52, 29 October 2006 (UTC)

Because of heavy funding by vested interests, there is an abundance of disinformation posing as scientific research [1]. Our objective here at WP is not to give creedence to disinformation, but report objectively on the science. Unfortunately, there are people who become caught in the snare of disinformation, frequently attempting to inculcate others with said disinformation. WP is not a place to 'compromise' between disinformation and science, and that sometimes upsets people. A good place for those people to start is the page on Scientific opinion on climate change. Skyemoor 18:35, 29 October 2006 (UTC)

I have no doubt that climate change is occuring and most of it is anthropogenic, but felt that the sentence was far too certain.--Rotten 15:51, 30 October 2006 (UTC)

Well, you felt wrong. Do you have any reasonable source for a claim that the human-induced component is not primarily caused by greenhouse gases? --Stephan Schulz 16:02, 30 October 2006 (UTC)

When did I say that? I said "according to this opinion this is wnot accept hat happens"... this is the prevailing opinion that GW is happening.--Rotten 18:02, 30 October 2006 (UTC)

But even (most of) those that do not follow the prevailing scientific opinion on AGW accept that the primary cause for the human induced component is the increase in greenhouse gases. Even if the prevailing scientific theory should change (fat chance...), the current version of the sentence will still be true. Your version is longer, and less informative than the current one.--Stephan Schulz 18:21, 30 October 2006 (UTC)

I wonder if Newton ever spouted the words "fat chance" about the physics he was uncovering as ever being partially debunked one day. There is no certainty in science, merely theories. Thegreatdr 17:42, 3 November 2006 (UTC)

Newton? Very likely. He had a very high opinion of himself! Also note that Newtonian physics is not "debunked". It's been recognized as one borderline case that covers essentially all of the situations humans commonly find themselves in to a very high degree of precision. A much better description is that it has been refined and extended to cover more exotic situations. With GW, I do not claim that the theory is set in stone. Indeed, it's a very active fields with new results probably every day. But the core (to oversimplify: greenhouse gases cause warming, more greenhouse gases cause more warming) is stable. --Stephan Schulz 18:04, 3 November 2006 (UTC)

Semi again

I've semi-protected this again, since the anon vandlaism seems to be getting rather high. Please discuss here if you disagree. Nb: unlike last time, can we keep this section for discussing the value of semi-prot, rather than the article in general. Maybe this thing needs near-permanent prot? William M. Connolley 14:33, 31 October 2006 (UTC)

Sprotect against a content dispute? Bad form. Kyaa the Catlord 15:03, 31 October 2006 (UTC)

Thanks for the semi-protect, the vandalism has been indeed high. Skyemoor 15:07, 31 October 2006 (UTC)

Potential Global Warming Gases Pie Chart Looks Nice but....

..where is the main human/animal direct contribution to the problem listed? This refers to our "normal" methane emissions as a contribution to the atmosphere. Growing populations will mean greater methane emissions by people and animals. Since methane is the most effective "greenhouse gas", it is worth representing that, somehow, if anyone has attempted to quantify it. If not, shame on them. Thegreatdr 11:18, 1 November 2006 (UTC)

The human "direct" contribution is negligible. To a good approximations, among mamals only ruminants produce significant amounts directly. Even if we only eat bean burritos, the cow that goes into them produces much more methane that we do. The numbers from agricultural animals are included in "Agricultural byproducts". See the primary source for more details. And methane is far from being the most "effective" greenhouse gas. As far as I know, that honour goes to some of the exotic CFCs. --Stephan Schulz 16:28, 1 November 2006 (UTC)

Actually, the worse of the ones that we track (possibly the worst there is, I'm not sure) is SF₆ at 22,000 times the global warming potential of CO₂ at 100 years. Used as an inert gas in high voltage electric systems, there is memorably a line item for tracking SF₆ leaks from high energy particle accelerators in the EDGAR inventory. Dragons flight 17:03, 1 November 2006 (UTC)

That's good to know. I couldn't find any methane data in the link supplied by Schultz. However, this source link states that 1/4 of all the atmospheric methane is a by product of animals. That would imply that there is some merit in including the information from people/animals into the pie. I was negligent in mentioning methane was the most significant greenhouse gas among natural sources. I had no idea that CFCs and SF₆ were that much worse than methane. In my perspective, CO₂ has not been proven to be as important as people claim it is. If it is, it must have a long shelf life since our atmosphere is a small fraction as warm as people were claiming it would be 20 years ago. Thegreatdr 17:45, 2 November 2006 (UTC)

Methane is CH₄. It's in nearly all the tables (and the main text) of the link I gave. Your source states that 1/5th of the methan emissions comes from farm animal. These are primarily cow and sheep (i.e. ruminants), and are included in the chart.

How much weight you give to different gases depends on the time frame. CFCs have a very high atmospheric lifetime, and SF₆ is around for several thousand years. CO₂ has a very complex behaviour because it strongly interacts with the oceans and the biosphere, but also has a very long average lifetime. Methane is reduced to carbon dioxide and water fairly quickly, and has a much shorter lifetime. So in the short term, methane is much more potent, but in the long term, CO₂ becomes more important. The global warming potential is usually calculated over 100 years. Finally, the atmosphere is not "a small fraction as warm as people were claiming 20 years ago". The increase in temperature may be a fraction of some outlandish claims. But the 1990 first IPCC report (16 years ago and the first major synthesis report) claimed 0.2-0.5 degrees increase per decade in the 21st century (assuming "business as usual, i.e. no significant special efforts to reduce emissions). This is very much in line with current estimates. Do you have a serious source for much higher predictions? --Stephan Schulz 21:24, 2 November 2006 (UTC)

I can check out my old Discovers from the mid 1980s. I remember claims of 2+C warming by the end of the century...but then again, the more extreme claims are likely to get media attention, and Discover was media driven. I'm glad the estimates came down based on your 1990 report. I now understand more why certain gases would be more significant than methane. Somehow I missed seeing the CH4 in the link. Thegreatdr 06:34, 3 November 2006 (UTC)

I don't know what "Discover" is, but it does not sound like a reliable source on such a topic. I don't think that any scientific publication predicted an increase of 2 degrees in 15 years in the 80s. I can remotely imagine that as the outer limit of a large error range for total warming since 1900 or so.--Stephan Schulz 08:39, 3 November 2006 (UTC)

Wow. You've never heard of Discover magazine? It's been published for 20-25 years now. Thegreatdr 17:37, 3 November 2006 (UTC)

Not in my country, or on my continent. Anyways, it looks like a popular science magazine. According to our own article, it went rather downhill in the mid-eighties, so I would not consider it a really reliable source. I'd certainly be interested in seeing the concrete issue you have in mind.--Stephan Schulz 17:57, 3 November 2006 (UTC)

New Source for some related article

This press release is about a survey on American public opinion on global warming as an environmental concern. Here is the main page for accessing the survey. [2] I'm not to sure where or whether this would fit into our coverage of the topic, but I suspect the editors here would know where it can be appropriately used. GRBerry 17:32, 1 November 2006 (UTC)

Graph on top of the page.

The graph on top of this page is very misleading. A glance makes you think that the temperature has risen drastically, which is not true (since it's still less than 1 point off of the average.) It might be better to remove this graph, or present a wider y range to make it less misleading. Animebop 23:57, 5 November 2006 (UTC)

The graph is clearly labelled. And a 1 degree increase in such a short time frame is drastic. --Stephan Schulz 06:51, 6 November 2006 (UTC)

Obviously a one degree rise over that time period is drastic, as we can compare it to all the accurately, consistently complied data dating back thousands of years. - Don Bradshaw —The preceding unsigned comment was added by 69.137.152.241 (talk) 19:23, 12 December 2006 (UTC).

A compressed Y scale is one of the classic techniques for overstating the effect of a change. It is classic enough to be specifically mentioned in How to Lie with Statistics, which is a more than 50 year old textbook on how to avoid abusing statistics. The site the image is sourced from does not appear to be an advocacy site. (If it were an advocacy site, that plus the technique would be reason to replace the image.) The source site itself is not a reliable site becase it is a Wiki, however the sourcing stated at that site for the image is solid enough for Wikipedia.

Another problem with such charts mentioned in the same text is choosing a X axis scale that is an atypical starting point. Looking at the 1000 year and 2000 year and even longer time period charts at the same site, this appears not to be an issue.

While I believe that the chart is not an advocacy chart, the question raised was legitimate and not one that should be summarily dismissed. Of course, it would be better to use a chart that has been peer reviewed and available for free use, but the odds of one of those appearing is very limited. GRBerry 14:35, 7 November 2006 (UTC)

So what y scale do you want? One with lots of white space? Seems pointless. The y scale is selected to fit the data. And the x scale is selected to fit the data too... this is the historical record. You don't get to choose the start point William M. Connolley 15:18, 7 November 2006 (UTC)

The data is peer reviewed and the image is free, what more do you really want? There are big labels legible even in the thumbnail, so everyone has the opportunity to judge the scale for themselves, and is WMC says, it was chosen to fit the available historical record, which is not something we get to choose. The source site is closed wiki, with only one significant author - me. So, you don't get to say it is unreliable unless you are planning to condemn all my work. Dragons flight 17:27, 7 November 2006 (UTC)

Financial effects

Stern's research (Stern Review) also predicts that mitigation would cost be very cheap compared to the expenses to be paid later on. Only 1% of the gross domestic product needs to be spend to avert economic devestation comparable to a world war or a Great Depression. 81.245.172.195

Ice age lag-leads stuff

People may be interested in the talk at Image talk:Co2-temperature-plot.svg William M. Connolley 12:35, 9 November 2006 (UTC)

Archive?

Long enough to archive again? Mostlyharmless 07:53, 10 November 2006 (UTC)

Sure Vapour

rv Vapour; why

Vapour changed the intro quote. Based on Intro. "most of the warming..." quote is distorted. I suspect that the word "likely" has been deliberately omitted he has done so for the wrong reasons. The quote is direct from a section header on that page and not distorted; omitting "new and sig" hardly seems like a distortion either. In what direction? Having two near-identical quotes seems pointless William M. Connolley 13:36, 17 November 2006 (UTC)

Compare the current version "most of the warming observed over the last 50 years is attributable to human activities" with "There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities." (which is likely to be the quote) or "In the light of new evidence and taking into account the remaining uncertainties, most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations." This kind of deliberate misrepresentation of source material is unacceptable. This wikipedia article make the human cause of global warming as an indisputable scientific fact, when the source material clearly indicate otherwise (66%-90%). Moreover, this site is not about the truth but attribution of POV and fact (NPOV). It is fundamentally important that the statements are attributed to IPCC instead of weasel expression such as "most scientists". If you do not make valid counter argument based on wikipedia policies, I would like to revert. My edit accurately describe and attribute the sources material. The current wikipedia version does not. Vapour

This is the summary, and should be as succinct as possible, not overloaded with caveats. The statement *is* from IPCC; and it *is* attributed; but it is also the prevailing opinion - as backed up by the link to sci-op. Your edit over-complicates; and the attempt to make it "only" IPCC opinion is POV on your part William M. Connolley 20:26, 17 November 2006 (UTC)

The current wikipedia version categorically assert that human activities are the cause of most of the warming observed over the last 50 years. The actual statement in the source only state that there are much stronger evidence for such argument. By selectivly censoring a part of the statement, the meaning of the souce is completely distorted. It's not just soapboxing. It a blatant (and likely to be intentional) misrepresentation. Vapour

There's a whole "Causes" paragraph further down. As what Vapour mentions is a matter of broad public interest, if not of broad scientific interest, some more about causes could be mentioned briefly in the abstract at the top. Narssarssuaq 01:58, 18 November 2006 (UTC)

Which provide no excuse for the distortion of the source. "There is new and stronger evidences for A" or "It's likely to be A" are categorically not same as "A is the case". Vapour

The article doesn't say "A is the case". It says the prevailing opinion is A; and backs this up. Nor does omitting "new and stronger" make any real difference William M. Connolley 09:22, 18 November 2006 (UTC)

Wrong. The original source article list such causes/evidence to show that "A is likely" or "there is new and stronger evidence for A". By (wrongly) stating "A is the case", you make all the listed causes to be more definite than it is. By stating that "prevailing opinion is that A is the case" the entire causation aspect of the article is skewed. There is a great difference in context of listed causes/evidences, if one, for examply, state that (1)OJ is guilty (2)OJ is lilely to be guilty.

Moreover, it's not 66-90 percent scientist saying A and 10-44% scientist saying not A, hence "A is likely". It's IPCC which express opinion that "there is new and stronger evidence for A and therefore, A is likely". No where, as far as I know, IPCC claim that they represent 66-90% of scientist. And if they say their paper do represent "prevailing opinion", the interpretation that '"A is likely" is the prevailing opinion' must be sourced to IPCC. It is an original research to impose extra interpretation that IPCC represent "prevailing opinion". Otherwise, what the point of wikipedia gudeline stating that "weasle word" is undesirable. If one want to qualify the authority of IPCC, do so by refering to what IPCC is, which agains have to be sourced from reliable sources.

It ought to say "According to IPCC, A is likely to be the case." or "According to IPCC, there is new and stronger evidence that A and therefore A is likely to be the case." When something state "there is stronger evidence", it only refer to relative change in likelihood. It could be change from "likely" to "more likely" or "uttterly improbable" to "improbable". Only by qualifying the current state to be "likely" this relative reference in the source article is put in context.

In criminal proceeding, expert opinion like "A is the case according to prevailing opinion" instead of "A is likely according to such and such sources." or "there is new and stronger evidece that A according to such and such sources and therefore A is likely" could get an accused convicted beyond reasonable doubts. This kind of misrepresentation by a professional expert could result in a charge of professional misconduct. Oh, and if I omit "could" from the previous sentence, don't you agree that I would be making a stronger case for the probability of charge occuring?

And lastly, if you say it doesn't make a difference, why did you revert it? Vapour

The exact wording of the statement is the IPCC's. But the sentiment is not - which is why the sci op page page documents its adoption by various other agencies. Which is why calling it the IPCC opinion is wrong William M. Connolley 20:00, 19 November 2006 (UTC)

Are we in agreement that stating "there is new and stronger evidence that A is the case" is entirely different from stating "A is the case." and therefore, more appropriate quote would be "A is likey to be the case" (which is a different quote sourced from the bottom of the page). Or we can alternatively summarise it as "there is new and stronger evidence that A is the case, therefore A is likely (66-90%) to be the case" which also indicate the relative change of assesement from the past.

As of attribution of quote/fact/opinion, are we in agreement that IPCC="prevailing scientific opinion on climate change" without verifiable reference describing it as such would amount to an original research/interpretation? We could also say "According to IPCC's report" instead of "According to IPCC". It's a bit anal but I guess it is possible to argue that reference of "according to" to an organisation could refer to the organisation's opinion. Saying "according to IPCC's report" would merely reflect what is said on the report. You are free to describe what the IPCC's report represent in term of "prevailing scientifi opinion" as long as you can find verifiable sources. Vapour

We're obviously not in agreement, and I think you've failed to read what I've written just above. Let me repeat it, since you're finding it rather hard: The exact wording of the statement is the IPCC's. But the sentiment is not - which is why the sci op page page documents its adoption by various other agencies William M. Connolley 12:27, 20 November 2006 (UTC)

Firstly, you haven't answered whether we are in agreement that "there is new and stronger evidence that A is the case" is different from "A is the case". Secondly, you have not indicated whether we are in agreement that the current edit that "IPCC=prevailing scientific opinion" would amount to an original research unless such interpretation is referenced from a verified source. And lastly, I read you. I specifically suggested "according to IPCC's report" instead of "according to IPCC". Can't you tell the difference? Vapour

I can't see the point you're trying to make with a distinction between "according to IPCC's report" and "according to IPCC". It sounds like you're saying IPCC may not agree with its own report. Given that the whole purpose of IPCC is to issue periodic reports on the state of the science, it's quite a stretch to contend that IPCC issues reports that it doesn't agree with. If that's not the point you're trying to make, please clarify. Raymond Arritt 04:14, 21 November 2006 (UTC)

Confidence interval

The article says,

"Models referenced by the Intergovernmental Panel on Climate Change (IPCC) project that global temperatures might increase between 1.4 and 5.8 °C (2.5 to 10.5 °F) between 1990 and 2100".

Actually, unless the confidence interval of this range is given, or guessed, (or assumed to be the conventional 2sigma or 95%, see standard deviation), this statement is almost devoid of information (apart from it being possible to estimate some expected value). What is the probability of getting within this range? 30%? 50%? 67%? 95%? 99%? 99.999999%? It actually makes a lot of difference. Someone should try digging up this small but vital piece of information, which to me seems impossible to find anywhere. Narssarssuaq 20:28, 18 November 2006 (UTC)

As far as I know, the range comes from combining the 95% confidence interval for climate sensitivity with a "plausible" range of emission scenarios that the IPCC has not assigned probabilities to, as that is outside the scope of climate science and depends on political and economical circumstances. So there is no real confidence interval. If you assume that the emission scenarios bracket real emissions, the prediction is "at least 95% likely". --Stephan Schulz 21:00, 18 November 2006 (UTC)

It's impossible to find this information because it's not meaningful and to my knowledge has not been computed. The model projections are realizations of specific scenarios and thus are not independent samples from an underlying distribution; i.e., in statistical terms the central limit theorem does not apply. Therefore, there is no basis for assigning a measure of central tendency or a confidence interval. Raymond Arritt 21:21, 18 November 2006 (UTC)

Upon re-reading the article's abstract, I think it looks OK, as sensitivity data are actually given. Increased precision in the article regarding the uncertainty (a concept that's often misunderstood by non-scientists, btw) would, however, be advantageous. I can't think of anything to add myself, so I'll leave it to you experts. Narssarssuaq 22:15, 18 November 2006 (UTC)

Again I smell bit of spining. The original paper clearly state that human is likely (66-90 conficence) to be the primary cause of global warming. Usually, prediction is less certain than analysing the cause of the past event. Vapour

Here we go. Reading of the source reveal that "The globally averaged surface temperature is projected to increase by 1.4 to 5.8°C (Figure 22(a)) over the period 1990 to 2100. These results are for the full range of 35 SRES scenarios, based on a number of climate models. 6, 7". [4] Omiting the reference to "the full range of 35 SRES scenarios" change the context greatly as it's obvious that probability of each scenario are different. The assessement of IPCC which give more definite discription of probability is in the same page. It says, "Climate sensitivity is likely to be in the range of 1.5 to 4.5°C. This estimate is unchanged from the first IPCC Assessment Report in 1990 and the SAR." And the word likely in the paper is defined as 66-90% confidence interval. Would be nicer if they give different range for different confidence interval. Given that the later quote give proper assesement of probability, I would consider this to be a better quote. Reference to projection of 1.4 to 5.8 is acceptable as long as it mention "the full range of 35 SRES senarios" which put such quote in a proper contenxt. Vapour

The article already says that the range is dependent on CO2 scenario. But, the distinction between this and sensitivity is an important one which is often confused; so I've rephrased it to make it more obvious, I hope William M. Connolley 19:56, 19 November 2006 (UTC)

Looks good. Do we need a (short) article on emissions scenarios? Alternately we could add a link to the SRES report, or to the discussion of emissions scenarios in the TAR. Raymond Arritt 20:50, 19 November 2006 (UTC)

Added "likely (66-90%)" to give a better idea of what this estimation entail. Vapour

Effects of global warming have started

there should be a section that details the effects that are occuring right now http://www.cnn.com/2006/TECH/science/11/21/climate.species.ap/index.html

Ecosystems

CNN recently came out with a news story about Scientists that have discovered that species and ecosystems are already being adversly affected by Global Warming; An example was given that 70 species have already gone extinct because the habitats they lived in have disappeared. I have a source for this, but I have no idea how to cite it. Can someone tell me/cite it for me? (The article is on the front page of www.cnn.com, but I'm too lazy to directly link to it right now). This is more or less a part of this article that needs to be changed from will happen to is happening. I anticipate this won't be so uncommon in the near future. Specusci 18:12, 22 November 2006 (UTC)Specusci

Ah, I see the gentleman above me has already linked to it. Specusci 18:13, 22 November 2006 (UTC)Specusci

You should, perhaps, also cite the source article for that CNN story: C. Parmesan (2006). "Ecological and Evolutionary Responses to Recent Climate Change". Annual Review of Ecology, Evolution, & Systematics. 37: 637–669.[5] Deditos 15:10, 24 November 2006 (UTC).

Scientific Opinion

One of the major problems with this article is that it makes no distinction between the opinons of "environmentalists" and actual atmospheric scientists. The IPCC's claims are in many regards faulty, and there is also some question as to possible ulterior motives of the IPCC. A more Bold textscientificBold textdiversity of claims would be most appreciated, as atmospheric scientists tend to actually be quite neutral on the subject of climate change's causes. —Preceding unsigned comment added by Great Scrivener (talk • contribs)

The entire article is about scientists... what made you think otherwise? If you want the IPCC's opinions to be faulty, you'll have to do more than just assert it; ditto your claims to speak for atmos sci William M. Connolley 17:05, 23 November 2006 (UTC)

Oh, and you've confused high C14 with high CO2. CO2 was *low* during the last ice age... William M. Connolley 17:07, 23 November 2006 (UTC)

+ve feedback

I've massively trimmed the new "positive feedback" section. This page is always in danger of bloat, and will become unreadable if much longer. Anything not really important should go into sub-pages.

I'm not even sure "+ve feedback" belongs where it is now... should really be in the mechaism section (where ice-albedo already is) William M. Connolley 19:36, 26 November 2006 (UTC)

MANIFESTLY FALSE STATEMENTS

JackMcGuire

The article contains statements that are manifestly FALSE.

As quoted, the EARTH COOLED from the 1940's through the 1970's, See Science magazine (Dec. 10, 1976); Science Digest (February 1973); The Christian Science Monitor (Aug. 27, 1974); Newsweek ("The Cooling World," April 28, 1975).

Yet the article FALSELY claims that the Earth has warmed over the last 50 years.

Since the Industrial Age began in the 1700's, the COOLING Earth from around 1946 to 1974 clearly casts severe doubt on man-made global warming.

AS A RESULT, THE ARTICLE IS FALSE, DECEITFUL, AND MISLEADING TO THE READER, IN VIOLATION OF THE GOAL OF CREATING AN EXCELLENT ENCYCLOPEDIA ARTICLE.

A GOOD ENCYCLOPEDIA DOES NOT *LIE* TO ITS READERS.

The article is FALSE AND DECEITFUL in claiming that global warming may reduce agricultural yields.

Higher moisture content in the atmosphere -- caused by warmer oceans -- plus higher carbon dioxide STIMULATE plant growth. The combination of moister air and carbon dioxide is an ideal environment for plant growth of all kinds.

Add to that longer growing seasons, and it is clearly FALSE that global warming can cause lower agricultural yields.

Carbon dioxide is a NUTRIENT in photosynthesis -- the foundation of all life on earth (since animals eat plants for food).

The article is also FALSE AND DECEITFUL in claiming that global warming will cause sea levels to rise. That is unknown and unknowable.

Precipitation -- rain and snow -- occur when moist air encounters a cold environment. Just as water condenses out of the air onto a cold lemonade glass or a cold window in the winter, a higher moisture content in the atmosphere would INCREASE snow and ice falling on the polar regions. This would INCREASE the snow and ice pack at the poles, transferring evaporating water from the oceans to the poles, LOWERING sea levels.

Furthermore, ice melts at 0 degrees C. But temperatures at Antartica reach only -30 degrees C IN THE SUMMER at the Coast. Ice does not melt at -30 degrees C. Increasing temperatures from -30 to -28 degrees C WILL STILL NOT MELT ICE. Ice does not melt at -28 degrees C any more than it does at -30 degrees C.

http://www.coolantarctica.com/schools/lesson_plans/fact_file_and_references.htm

Temperatures must EXCEED 0 degrees for ice to melt.

Warming from -30 to -28 doesn't get you any melting ice.

Jack McGuire

Thanks for discussing on the talk page. I have reverted your additions since they seemed to be largely uncited. The material you did cite comes from sources which are out of date in terms of their methods of paleoclimate reconstruction, and popular rather than peer-reviewed sources. In short, they no longer reflect the current scientific consensus. There are several issues to be dealt with in your edit: the cooling between 1946 and 1974. It would be problematic to take a short term trend and extrapolate, while ignoring the orders of magnitude larger long term trend. See, this article for more information about this. The material about the specific consequences of global warming are less well established, since they involve many biological interactions which are difficult to predict. I think if we can find citations to scientific sources which reflect a consensus opinion of climate scientists, then they should be included. Without them, however, it would seem like endless speculation. There is some recent empirical evidence that gloabl warming has a negative impact on animals, and there is substantial evidence that the ice caps are melting. I am not sure that there are sources which say what you have said, but if there are, cite them and we can discuss. Thanks, --TeaDrinker 04:23, 27 November 2006 (UTC)

Sea water is of course above freezing point, so it is at the interface of ice and water that global warming will produce ice melt, which of course compounds as sea levels rise. Also sea levels will rise even if there is no ice melt - as water warms, it expands. And sadly thirty year old references just don't cut it. --Michael Johnson 04:39, 27 November 2006 (UTC)

Still, he is quite correct about Antarctica melting: See Sea level rise. (By the way, salty sea water may melt at temperatures far below 0 degrees C). Also, if there was a significant lowering of global temperatures from 1946 to 1974, it may of course be mentioned, but the article is already too long. Narssarssuaq 11:59, 27 November 2006 (UTC)

There are no cites in Jack's discussion, and from my own reading on Antarctica, it's obvious that 0 C is exceeded frequently in the southern pole summer. Even readings from Scott, Shackleton, and Amundsen in the early 1900s confirm this. If Jack wants to provide scientific sources for his statements, then we would have a starting point for his assertions. Skyemoor 13:05, 27 November 2006 (UTC)

Indeed, Jack is getting confused between the continental mean temperature and the temp at the edges. He is, however, correct in that Ant isn't going to melt in a hurry; but he is wrong to imply that the article says it will. As for the 40's... there is a graph right up front with the temperature record on it. No, the T change then isn't very sig - only as a break in the warming. It gets a brief mention at the end of "Greenhouse gases in the atmosphere" section William M. Connolley 13:26, 27 November 2006 (UTC)

To do list

"Make the article neutral by including crititism of global warming and showing that it is not a proven fact." Is that really necessary? We have alternate theories AND the proven fact thing sounds like an import from the evolution type 'debate'. Brusegadi 04:21, 27 November 2006 (UTC)

Also, it is pretty muc general consensus that global warming is real, human cause or not; that, and I'm pretty sure everyone assumes that both sides are unproven, much like the Evolution/Creationism disputes. Specusci 16:36, 27 November 2006 (UTC)Specusci

I removed that bit William M. Connolley 17:01, 27 November 2006 (UTC)

The phrase "global warming is real, human cause or not" points to an important point that many misses: Global warming until 2100 is, at a certain degree of precision, predicted by models. Whether the present warming can be attributed to this predicted global warming or not is in principle beside that particular point. Present warming may consolidate the theory. Still, as there is a lot of "natural noise", such as solar and volcanic activity, plus weather fluctuations, involved in global temperatures, such an empirical consolidation of the theory will have to rely on a complex analysis of the situation, an analysis which is totally different from the modelling of future climate. I'm unsure if the article is clear enough on this point. Although it may seem self-evident for scholars, it seems some journalists, not to mention Average Joe, have problems with this. (Or am I wrong?). And as the Global warming article is most probably extensively used by such people, we may want to become slightly clearer on this point. Narssarssuaq 17:11, 27 November 2006 (UTC)

I have to wonder if you're reading the article, or just the talk page. A widespread scientific opinion on climate change is that "most of the warming observed over the last 50 years is attributable to human activities"[2]. is clear enough, with its link; as is causes" section William M. Connolley 17:37, 27 November 2006 (UTC)

I am reading both the article and the talk page, if you're still wondering... My point isn't that it's not mentioned, but that the divide isn't emphasised enough. Also, the first sentence reads "Global warming is the observed increase in the average temperature of the Earth's atmosphere and oceans in recent decades". True, and it's perhaps good enough, but it may be misleading not to mention that "Global warming" is also, and perhaps more often used about, the partially unrelated predicted increase in coming decades. I see the point of keeping the article concise, but as I said; I have a feeling that the article could be slightly clearer as to the divide mentioned. Narssarssuaq 18:02, 27 November 2006 (UTC)

German article Globale Erwärmung now a featured article!

Hey guys, this is off-topic, but for the better: It's for celebration! I'm the main author of the German sister article about Globale Erwärmung, so I guess it's up to me to thank you all for your contributions here, because both the content of this article and that of this very talk page played an important part in the German article about global warming becoming a newly elected Featured article. Thanks to all of you, please keep it up and enjoy the spread of your excellent work! Hardern 21:48, 27 November 2006 (UTC)

Congrats on a job well done! --Stephan Schulz 23:48, 29 November 2006 (UTC)

CO2 is accelerating

from the bbc.--Pixel ;-) 23:23, 27 November 2006 (UTC)

An Oxford professor in the article seems to claim that this indicates a too optimistic scenario distribution at IPCC. I hope it's an unreliable source. I guess we'll have to wait for the IPCC Fourth Assessment Report instead of quoting loose statements like that in this Wikipedia article. Narssarssuaq 01:11, 28 November 2006 (UTC)

I'd say Mike Raupach is pretty reliable source! (He gave a fantastic talk a couple weeks ago at a conference I attended.) Likewise Myles Allen is head of the Climateprediction.net super-duper-mega-ensemble project. But I'd wait for the dust to settle before including this as encyclopedic content. Raymond Arritt 03:05, 28 November 2006 (UTC)

(I was referring to the organisation doing the survey). Narssarssuaq 16:30, 29 November 2006 (UTC)

If the bbc got it wrogn we have the right to be wrogn too.--Pixel ;-) 13:33, 28 November 2006 (UTC)

True. Though this isn't wiki-news. I'm not sure how this is compatible with the trend in actual CO2 conc, which is *not* accelerating in the same fashion William M. Connolley 14:14, 28 November 2006 (UTC)

I'd say this graph: [6] shows a certain increase in concentration growth rate. Not sure if it corresponds to 1% -> 2.5%, though. Narssarssuaq 23:46, 29 November 2006 (UTC) By the way, this diagram [7] shows both that there is a strong correlation between atmospheric CO2 and global temperatures, and that present atmospheric CO2 is very, very high in a historic context. If IPCC models are to be right, the correlation so evident in the diagram doesn't apply for anthropogenic CO2 emissions. Has there been any research into this, establishing precisely how and why this is the case? Narssarssuaq 00:01, 30 November 2006 (UTC)

The CO2 curve is kind of bumpy-looking (there's a rigorous scientific term for you). I'd be hesitant to attach much significance to rate fluctuations on scales less than a decade or so. As for the second diagram you cite, look at the time axis. The time scale relevant to anthropogenic GH warming is a century or so. If I've done the math right, that would be invisible on your diagram -- i.e., less than the width of one pixel. There's no reason to expect that processes that are important on time scales of tens of thousands of years are the same as the processes that are important for a few decades. Raymond Arritt 01:51, 30 November 2006 (UTC)

You're right. Thanks. Narssarssuaq 01:54, 30 November 2006 (UTC)

I think it would be benificial to the overall purpose of the article that the largest affects of the current warming occur near the polar regions, thus having even more effect on ocean levels. —Preceding unsigned comment added by [[User:{{{1}}}|{{{1}}}]] ([[User talk:{{{1}}}|talk]] • [[Special:Contributions/{{{1}}}|contribs]])

Should we rename this article Globle Heating

Global warming sounds like something nice. Heating is something to be serious about. —The preceding unsigned comment was added by 75.72.176.177 (talk • contribs) 02:47, 30 November 2006 (UTC)

No, its most common name is Global warming. Wikipedia is about objective information, and not an arena for political (or other) agendas. Narssarssuaq 04:22, 30 November 2006 (UTC)

I just today read about somebody who suggests renaming the phenomenom. somebody else suggested "global climate disruption". But as long as its commonly called global warming, Wikipedia should stick to that. Hardern 22:13, 30 November 2006 (UTC)

Yeah... terrible idea. See WP:NAME. Mikker ^(...) 22:24, 30 November 2006 (UTC)

I Believe that was the President's press strategist-The "global climate disruption" guy167.128.221.98 18:40, 1 December 2006 (UTC)

So... I guess Global roasting won't fly either. ;^) --Richard 03:19, 1 December 2006 (UTC)