Talk:Climate change/Archive 7

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New Articles: Global climate change and Climate forcings

Please read the new articles and consider commenting on them and/or moving some material to either one. Note that climate forcings is not specific to global climate forcings, so if it makes sense to create a separate section please do.

I hope this helps get this part of Wikipedia sorted out.

Posted to all discussion pages listed in the "See Also" section of global climate change. --Ben 03:48, 2 Dec 2004 (UTC)

CM -> GCM

(William M. Connolley 20:51, 28 Mar 2005 (UTC)) I've switched Climate model to general circulation model and moved text too. Because... for the GW article, we want to link to an article which talks about the GW aspects of climate models... not one that patiently goes through the different types, most of which are irrelevant. ps: isn't it quiet round here...

A little light-hearted fun.

I thought some of you might enjoy this article, in the spirit of the season. Doubts about the Advent of Spring — Cortonin | Talk 26:20, 1 Apr 2005 (UTC)

(William M. Connolley 18:45, 2 Apr 2005 (UTC)) Glad you liked it...

Maybe it is just me, but does the notion of scientists making fun of their opposition bother anyone else? I know it was April Fools, and it is funny, but I would sort of prefer it if the scientific side of this debate stay somewhat more composed than publicly making fun of the other side. Dragons flight 20:52, Apr 2, 2005 (UTC)

(William M. Connolley 21:04, 2 Apr 2005 (UTC)) I think you're being somewhat po-faced. Its not only funny, but it also makes a serious point. However, I'm pleased to see you distinguishing the "scientifc side" ie RC from the unscientific ie MC side.

If their being scientists bothers you, just view them as not being scientists. (SEWilco 21:07, 2 Apr 2005 (UTC))

To be honest, I don't really think that making fun of one's opponents has much role in any debate, but I find it particularly unnerving when the side which wants to be representing the rational and reasoned scientific establishment resorts to making fun of the views of the other side.

Some people take MC seriously. An even greater number don't understand the debate. Some of these people are going to visit RC in the hopes of learning something. But look at how the April Fools parable will look to people that are confused or skeptical? Almost the entire posting says that doubting global warming is as absurd as doubting the seasons. Anyone who is skeptical or confused is going to have doubts, so by analogy, all of those people are morons. Even in the best case scenario, that article has given the skeptical a good point of evidence that their concerns will not be taken seriously at RC.

(William M. Connolley 20:07, 3 Apr 2005 (UTC)) MC has been ripped to shreds twice on RC, which is arguably taking him more seriously than he deserves (does he have anything sensible to say about the science of GW? I haven't heard it, if so). Some people take him seriously, indeed, in which case poking fun at him is probably a good idea. The motto of the parable, of course, is that cherry-picking short term trends (as people did with the satellite data before it started showing warming too; as people still do for isolated warming cities; etc etc) is silly.

Sure it's funny, and it is going to play well among environmentalists, and the already converted, but I had hoped that RC wanted to do more than preach to the faithful. One could easily have had fun with April Fools without making fun of others. For example, write an article saying: "We're sorry, this has all been a big joke. There has never really been any global warming." or "Climatologists agree: Bring on the heat. Winter was never any fun, anyway." or "Solution to Global Warming found: Breathe Less. Six billion humans expelling carbon dioxide at an alarming rate." There are plenty of ways to have fun with the holiday that don't involve mocking your opponents. And even if you feel compelled to mock MC, then you should at least have more than a few tacked on lines of self-deprecating humor (e.g. "tennis rackets") to give it comedic balance. Instead, RC seems to let their frustrations get the better of them and used April Fools as a thinly veiled excuse for attacking their opponents. Frankly, I'm disappointed in RC.

(William M. Connolley 20:07, 3 Apr 2005 (UTC)) I'm disappointed by your reaction. The piece is a joke. You appear to be suggesting that its the entirety of RC output, which is weird. It isn't even the entirety of the front page.

In order to be effective, scientists need to be respected as neutral arbitrers of truth. Part of that means being seen to take criticism seriously, even when there are good reasons to believe that the criticisms are ultimately without merit. The members of RC want to portray themselves as the representatives of the scientific climate establishment on the net. If they then go out and malign and make fun of the opposition that does a disservice to the credibility of scientific establishment and ultimately to all of us. If RC wants to represent the voice of the climate establishment, then they ought to be willing to hold themselves to a higher standard.

Dragons flight 23:51, Apr 2, 2005 (UTC)

Does being a scientist mean that you have to surrender your sense of humour, your ability to use jokes or parody? I sure hope not (I've gone to far to have to find a new career now!) Guettarda 23:31, 4 Apr 2005 (UTC)

Rm Silverbacks solar and vert profile

(William M. Connolley 09:33, 11 Apr 2005 (UTC)) I removed solar from the commitment section. Solar is only one influence after GHGs, and probably not the largest: sulphate aerosols are larger. So there is no reason to single out solar. The std commitment stuff is purely in terms of CO2, anyway.

As for vert profiles: well yes, the models have flaws. That one isn't usually pulled out as one of the largest and I'm not sure why its supposed to be there.

Suphate aerosols are not mentioned because the literature shows the unrealized commitment is warming, they are considered a cooling influence although perhaps, there has been a recent reduction in their levels contributing warming that is unrealized. One thing the commitment studies show is that ocean equilibration takes centuries or millenia, so any persistent increase in solar activity that is thought to have contributed to the pre-1940 climate is not yet equilibrated. --Silverback 09:46, Apr 11, 2005 (UTC)

(William M. Connolley 13:27, 11 Apr 2005 (UTC)) The text is:

Climate commitment studies predict that even if levels of greenhouse gases and solar activity were to remain constant, the global climate is committed to 0.5°C of warming over the next one hundred years due to the lag in warming caused by the oceans.

and I've bolded your addition. My point is that there is no reason to single out solar in this fashion. If you're interested in second-level effects, ie things other than GHGs, then you should talk about sulphates first. The fact that they are a cooling doesn't matter. I also think you are over-confident about the size and even direction of the solar influence.

As for the vertical stuff: yes of course its in the literature (not that arxiv is the literature, of course). So are lots of things. Adding (your bit in bold) Much of this uncertainty results from not knowing future CO₂ emissions, but there is also uncertainty about the accuracy of climate models, especially the representation of clouds and the failure to correctly model the vertical temperature profile over the tropical oceans[1]. is not justified. I don't think the vert prof bit is an especial concern. Just about everyone agrees that clouds are, which is why they get a special mention.

The models show that significant warming of the troposhere is a characteristic of greenhouse gas forced warming, yet the data does not show this characteristic,

(William M. Connolley 15:31, 11 Apr 2005 (UTC)) No - this is somewhere between false, and overstated. Singer et al (of course S is noly 3th author, so we shouldn't really be calling it S's paper) deliberately truncate the data to avoid seeing any warming, so of course they don't see any warming. If you use the full data series, you see warming: in all versions of the satellite (or balloon) record. Some of those are consistent with models and balloons, some not. Saying "*the" data..." isn't correct: there are multiple datasets.

and the disparity is especially significant over the tropical ocean. You yourself stated that the IPCC also noted this problem. The latest research is evidence that different data sets show the disparity, and conclude that the models apparently have problems at the tropical ocean surface. You know this, because we have discussed the papers. You are being obstinate and dismissive, of the most recent peer reviewed results.

(William M. Connolley 15:31, 11 Apr 2005 (UTC)) I know the problem; the tropical ocean stuff I'm less sure of.

(William M. Connolley 15:57, 11 Apr 2005 (UTC)) Also (I've just read but not digested this) if you think that S+C's version is validated by the radiosondes, then look at Agudelo and Curry, GRL 2004 L22207: table 1: radiosondes: 0.044 oC/decade; colocated MSU: 0.121 oC/decade (1979-2001). And they go on to say: a foruitous (and potentially misleading) agreement between the "global" estimate using the homogenised radiosonde data set (87 locations) with the global MSU value masks a factor of 3 difference in the collocated temperature trends.

Unfortunately, I don't have full text access to this article, and I can't find it in arxiv, although, that sites search capability does not inspire confidence. The end of the abstract was intruguing, but I'm not sure what they meant: "that the models used for the reanalyses are simulating the necessary dynamics/thermodynamics that could lead to a tropospheric cooling in contrast to a surface warming (and vice versa). "--Silverback 17:23, Apr 11, 2005 (UTC)

I am sorry your block lasted 48 hours, but you should have emailed the wikien-l email list when you noticed the problem.

Feel free to include the suphate aerosols if you wish.--Silverback 14:27, Apr 11, 2005 (UTC)

(William M. Connolley 15:31, 11 Apr 2005 (UTC)) This isn't the point: there is a page called commitment studies. It has the details on it, or should have. Minor effects shouldn't be on the main page.

As far as solar, here is a quote from the Wigley paper

• • "For past forcing, I considered the effect of natural forcings from solar irradiance changes and volcanic eruptions, and uncertainties in aerosol forcing."

Here is a quote from the Meehl paper:

• • "The 20th-century simulations for both models include time-evolving changes in forcing from solar, volcanoes, GHGs, tropospheric and stratospheric ozone, and the direct effect of sulfate aerosols. Additionally, the CCSM3 includes black carbon distributions scaled by population over the 20th century, with those values scaled by sulfur dioxide emissions for the rest of the future climate simulations. The CCSM3 also uses a different solar forcing data set for the 20th century."

--Silverback 14:48, Apr 11, 2005 (UTC)

(William M. Connolley 15:31, 11 Apr 2005 (UTC)) Yes, I know full well that solar effects are included. What magnitude and sign do you think they have?

Since some warming occurred in the late 1800s and before 1940 before the most significant greenhouse gas increases, this is probably due to increased solar activity. While some of the unrealized climate commitment from this warming probably accounts for some of the warming in the latter half of the 20th century, given the long equilibration times, it is probably still accounting for some of the commitment afterwards.

(William M. Connolley 15:57, 11 Apr 2005 (UTC)) Sorry: what I meant was not, "what is your opinion" but: what do the refs say? You've been quoting refs for the commitment stuff: presumably they say this, or if not that is significant.

No, they don't say whether or not it is significant, they have no way of knowing without doing the study. As you know, the studies in this area are few, and we've reviewed them all.--Silverback 16:33, Apr 11, 2005 (UTC)

(William M. Connolley 16:52, 11 Apr 2005 (UTC)) Ah, OK, thats what I thought, and thats what my problem is. You appear to be saying that you know/think that the solar effects have lead to a significant (or at least worth mentioning) commitment to warming from solar forcing. I'm not convinced of that. In fact I'm convinced of the opposite: that after GHGs the next most sig commitment component would be a negative one from sulphates (ie, that the warming seen so far is rather less than you might expect because sulphates have been keeping the increase down; this of course is factored into the std climate runs). I can't properly substantiate this, but http://www.grida.no/climate/ipcc_tar/wg1/figspm-3.htm is relevant.

I have no problem with you mentioning criticisms of the Singer co-authored studies, especially, since I would like to point out that the climate commitement studies were run from the current climate, and if run instead from the 1940 climate might show that some of the warming already experienced and even that in the 1990s generally attributed to GHG, was due in part to climate commitment. I suspect the climate has been lagging behind as solar activity increased since the little ice age.--Silverback 15:50, Apr 11, 2005 (UTC)

(William M. Connolley 15:57, 11 Apr 2005 (UTC)) I'm puzzled by your "I have no problem with you mentioning criticisms..." - presumably, you mean "from refs", rather than my own personal opinion?

I mean from refs or from your reasoned criticism or explanation, not your "opinion", there is a difference. --Silverback 16:33, Apr 11, 2005 (UTC)

(William M. Connolley 16:52, 11 Apr 2005 (UTC)) I'm thinking of the SEPP page of course, where reasonned criticism was rejected as pers res - though perhaps not by you.

(William M. Connolley 12:00, 12 Apr 2005 (UTC)) This is getting weird: Sb now reverts with I didn't state that it was a "key" problem, but it is interesting that you think the clouds and aerosols are more serious, I'd like to see a good cite, not just the IPCC on this when his previous revert said adding aerosols, no reason to shift key problem to lesser page, it is not just a technical detail. Come on, try for some consistency please!

As for the text: just about everyone agrees that clouds are a key problem. I see no evidence at all for similar agreement on the tropical stuff.

Sorry, I didn't get the drift of your comment, and forgot I had used "key" because you interpreted it differently than I intended. I was thinking of the vertical temperature profiles as "a key" problem, not "the key" problem. I know the temperature profiles were serious enough for the satellite data (now confirmed by other data), to create embarrassing problems for the models. While I suspect that clouds and aerosols are just as serious, the profile discrepancy is harder data easier to quantify. I suspect that the cloud issue is harder to quantify, since at any given timepoint the distribution of clouds is not expected to match any particular data. I suspec the comparisions are probably global norms like percentage of cloud cover over a period of time, and perhaps even over specific areas averaged over time. Hopefully they even insist on a proper distributed of cloud times, in different climates. Of course, getting the N pacific occilation and ENSO right is important too. I don't envy the modelers their task and appreciate their work, I just don't think we should put much stock (certainly not hundreds of billions of dollars worth) in their predictions yet.--Silverback 12:25, Apr 12, 2005 (UTC)

Among other things, solar activity DOES need to remain fairly constant for the temperature predictions of commitment studies to be accurate. Solar activity does naturally vary, so we should make note when the assumption of constancy is assumed. And the altitude problems are well documented. — Cortonin | Talk 16:58, 12 Apr 2005 (UTC)

No global warming according to NASA

I just found an article on a NASA site ([2]) that says satellite measurements show no global warming in the two decades ending with 1997 and questions the accuracy of computer models. The article cites a paper in Nature, a respected peer review journal, that verifies the accuracy of these measurements. I don't have time to incorporate this into the GW article so I'm leaving it to someone else.

Investigation of the temperature discrepancies between satellite and surface data, and the predictions of models is still an active area of research and a problem for the modelers and the debate has progressed quite a bit since 1997. Here are a couple journal articles that we were just discussing recently if you want to update yourself on the current status: [3] [4]. I am going to remove your older reference from the article because the older information will just confuse the issue. Thanx for letting us know what you found.--Silverback 17:58, Apr 12, 2005 (UTC)

To a neocon or even any con...

Global warming is the central underpinning of Environmentalism which is Communism repackaged for consumption by Westerners who are used to abundance (this unsigned comment by User:JohnSmith777).

You damned fool: Communist governments had far less concern for the environment than modern Western governments. As well, the tenents of environmentalism far predate global warming concers, though currently, GW is a central issue. --D. Franklin 04:23, Apr 25, 2005 (UTC)

Please remove your personal attack from your comment, it is considered flaming. -- Natalinasmpf 05:42, 25 Apr 2005 (UTC)

Both of you are wrong. Communism is an ideology socioeconomic model, and whether the policies it decides to do (far-sighted, moderately environmental policies which say, keep the forests for the next millenia, or the short-sighted but highly industrial policies which increase the GDP by 10% every year but run out of forest within the century) depends on the citizens. And stop flaming please. Global warming is a HYPOTHESIS set out by a group of people across the political spectrum who observed a certain phenomena taking place and hypothesised about it, although I think they are wrong. Oh, communist governments are actually more considerate. I do not refer to Cuba, the Soviet Union, North Korea or the like, those are state capitalist governments, not actual communist governments which would actually follow the model of anarchism, which also would be more environmentally friendly. Even within a certain ideology, the industrialist versus environmentalist attitude is a subset and is not specific to the SOCIOECONOMIC ideology such as capitalism/communism. And JohnSmith777 assumes communism is an ideology which advocates centralised collectivist oligarchies. This is not the case. It is actual more like a decentralised collectivist anarchy. Not to be confused with anomie either. Because it is based on a gift economy, rather than a profit driven one, its policies would therefore be more far-sighted. -- Natalinasmpf 05:05, 25 Apr 2005 (UTC)

Yes JohnSmith777, it is all a big commie plot, now drink this lead based solution, and I'll teach you some more about liberals. Liberals say lead makes you stupid because the commies want to destroy industry. Toxic waste is actually good for you, but they don't let us throw it into the water supply because they want to create welfare jobs. Cancer is a big scam invented by greedy liberal doctors to suck dry corporations.

This link better

The bias of certain posters from sci.environment and alt.global-warming is evident in this wikipedia article. A better article that frames the issues in terms of pros and cons instead of 'received wisdom circa 2005' is this site: http://www.answers.com/topic/global-warming-controversy User: raylopez99

Which was copied from global warming controversy. — Cortonin | Talk 08:46, 19 Apr 2005 (UTC)

positive effects of carbon dioxide != positive effects of global warming

I came across the article to discuss add in the content that a rise in carbon dioxide levels is more crucial than what the article said before (due to carbon dioxide starvation and all), but then I realised "positive effects" meant the positive effects of global warming...now, global warming doesn't cause CO2 increases, no? Also, the argument also runs not the either way round for a certain extent (the heat trapping effects plotted on a graph, for example, levels off)...I added in my content, but I was kind of too bedazzled to fix it (yet). Does someone with free time have time to fix this? -- Natalinasmpf 01:26, 20 Apr 2005 (UTC)

Well, actually there are a number of records which show past warming events took place before CO2 increases. (SEWilco 02:24, 20 Apr 2005 (UTC))

Hmm yes, I just remembered that was one of the arguments against the Kyoto protocol. But what I meant is that generally, the idea that "increasing atmospheric carbon dioxide (a suffocating 300-600 parts per million to plants, compared to 210,000 parts per million of oxygen) increases plant growth" should be listed as a proponent for benefits of increased carbon dioxide, not global warming itself. -- Natalinasmpf 02:27, 20 Apr 2005 (UTC)

Perhaps CO2 effects should be in the carbon cycle article. However, if there is any relationship between CO2 and warming then perhaps it should be mentioned among effects. And have you seen a heat trapping graph? (SEWilco 02:50, 20 Apr 2005 (UTC))

Yes, I have, but in my perspective I have always considered this a side effect that carbon dioxide isn't linearly related (neither exponentially, maybe more like a quartic function or an S-shaped kind of one) to rise in global temperatures, rather than the fact global warming causes carbon dioxide increase. My proposal is to mention the argument that "carbon dioxide increase" may not cause global warming in the first place, never mind the benefits of any global warming should it take palce. And that while at the same time, carbon dioxide may also be beneficial. -- Natalinasmpf 03:06, 20 Apr 2005 (UTC)

"the fact global warming causes carbon dioxide increase": Actually, there tends to be an increase in methane after warming, with CO2 increasing even later. And after the chemical acrobatics in the atmosphere, methane breaks down into water and CO2. If this stuff were simple… (SEWilco 04:09, 20 Apr 2005 (UTC))

DragonFlight attempt at compromise

(William M. Connolley 22:05, 20 Apr 2005 (UTC)) I'm fairly happy with the DF version (thanks). I would like the intro para to be stronger now: the sci op para says "most of the warming observed over the last 50 years is attributable to human activities" so the intro is now rather over-vague.

400 kyr pic

(William M. Connolley 21:16, 21 Apr 2005 (UTC)) Well, here we go again, a re-run of the exactly-which-graphs shall we use question. TJH's original idea that replacing the last 100 years with the past 400kyr is obviously absurd; sadly Cortonin has now jumped onto this bandwagon. All we ned now is for Dnorris to return. The article (as it should be) is about the most recent climate change; the intro doesn't mention the long term at all. So including the long term graph there is not at all sensible. Note that further down DragonFlights nice last 2000y graph *is* included for long-term perspective.

LOL. Curious William, what exactly is your preferred timeframe for this "issue"? Ten months? Twenty years? 100? LOL. New graph includes years in short graph, but also includes additional years' data. thejackhmr

(William M. Connolley 21:22, 21 Apr 2005 (UTC)) Sadly, yes, I think you are laughing: ie, you're just trolling on this article. The obvious timeframe for GW is about 100 years. Which is what the article talks about. As I said. Now, try answering the points I raised. Since Cortonin has joined in your silly game, he can answer too.

You'll have to explain this "obvious timeframe" of yours. Please entertain how can one predict if the earth is cooling or warming without looking to see if the earth was once previously cooler or warmer? LOL! How absurd. thejackhmr

(William M. Connolley 21:43, 21 Apr 2005 (UTC)) Well, have you considered actually reading the article, to discover what its about? If you do so, you'll find that the pic is out of place.

Hmm... does seem rather absurd to insert a 420kyr. graph in an article focussing on the las150yr or so. I moved the image in question to climate change where it seems more relevant to me. But, I dunno - maybe out of place there also. Vsmith 21:32, 21 Apr 2005 (UTC)

150yr? Why not 151? LOL. thejackhmr

thejackhmr is correct that graphing a trend is irrelevant without putting it in a larger context to show how it fits. It's 10 degrees hotter today than it was yesterday, and if I plot that on a graph you'd think I would die of heat stroke next week unless you also include a larger context for comparison. Selecting subsets of data allows you to present virtually any trend, but showing larger quantities of data allows you to show significance of a trend. — Cortonin | Talk 21:51, 21 Apr 2005 (UTC)

(William M. Connolley 22:02, 21 Apr 2005 (UTC)) Precisely: graphing trends for irrelevant periods is irrelevant. Adding a 10-day picture would make no sense; adding a 400 kyr picture ditto. And you've totally failed to answer my point: the 400 kyr frame is not what the article is about.

Adding the 10 day picture is irrelevant because the data analysed is too narrow to make a conclusion on the overall effects. However, adding a 400,000 year time frame isn't, because it has a wider, and therefore better, picture. In our global warming case, has the variable been isolated to figure out whether it the rise in temperature is a natural trend or a man-made effect? A 400,000 year graph helps this. A 150 year graph is only sufficient for stating a fact within the 150 years, not for making conclusions about the long-term future. -- Natalinasmpf 22:43, 21 Apr 2005 (UTC)

I am a fan of context, but that picture really doesn't fit. Right now there is almost no discussion in the article about ice age cycles and very long term variations, and without such a discussion a reader doesn't have enough information to make sense of the 400kyr plot. Also, unless someone can provide a serious argument that recent global warming is related to ice age scale orbital variations, I don't see any point in adding that discussion to this article. Simply dropping a plot in to point out long-term natural variability is a red herring unless you also explain that most scientists believe that the ice age variations are caused by an entirely different physical mechanism than recent warming. Dragons flight 23:10, Apr 21, 2005 (UTC)

First, there should be more discussion of long term variations, since the exclusion of those leaves a hole in the associated issues, but addition of such information is mostly suppressed by the same process demonstrated here. — Cortonin | Talk 01:27, 22 Apr 2005 (UTC)

But more directly, the 400kyr plot provides a context for interpreting the significance and meaning of the projections of climate models. It shows us how the temperatures have fluctuated, and the magnitude of those fluctuations, over the course of human existence. It also shows where we currently are on this temperature range. This gives us a metric for understanding what the effects will be in terms of what humanity has already experienced (which relates to understanding the Potential Effects section). It also gives us an indication of where the long term natural trend will go over thousands of years, which appears to be down by another 6-8 degrees. I for one am interested in the changes to the climate beyond just the next century. — Cortonin | Talk 01:27, 22 Apr 2005 (UTC)

Read a bit further in the article, the 2000yr image is there for your perspective and context. The longer term issues are discussed at length in Climate change where I had moved the image in question. However, as the image has no copyright tag, I removed the link to it and replaced with a similar image [Image:Vostok-ice-core-petit.png] that has more info and has a copyright tag and is used in a variety of climate articles. The insertion of the image here appears to have been simply to obfusticate - (skeptic POV ploy). Read the climate change and associated articles for your desired (and valid) context, don't try to obfusticate this article by overloading it with all that "context". Vsmith 03:20, 22 Apr 2005 (UTC)

The 2000yr image only shows a portion of the context. It doesn't show a large enough portion to see the range of the rate of changes. As a geologist by training, I would think you would support interest in examining the effects on the longer time scales as well as the short ones. The Vostok-ice-core-petit image you suggested doesn't quite cut it, because it has no temperature scale on the Y axis, and thus provides no context for temperature changes. You seem to think the purpose of the global warming page is to make the case for global warming. I instead see the purpose of the global warming page as to present information and theories relating to global temperature changes. And the larger timescale image relates here, because the topic of global warming is more general than just a single-century anthropogenic CO2 topic, especially given the definition at the top of the page. — Cortonin | Talk 10:19, 22 Apr 2005 (UTC)

As a geologist I am interested, but the needed info is in and referenced to other articles from this page. It all doesn't need to be here - and insisting on including more and more clutter to weaken this page by including info not directly pertinent is an obvious tactic used by your skeptic allies to obfusticate. Why not as well include info on Snowball Earth and earlier Archaen climate changes? The obvious purpose of this page is to discuss the direct and most pertinent evidence for global warming over the past couple hundred years. And the anthropogenic aspect IS the main focus - it is the one we may be able to control or ameleorate. Vsmith 15:26, 22 Apr 2005 (UTC)

This is why people have been accusing you of pushing POV. You treat the purpose of the page as to discuss the strongest evidence "for" global warming, only considering the past couple hundred years, and focusing only on the things humans can control. This is not a neutral description, this is advocacy for political action. — Cortonin | Talk 17:17, 22 Apr 2005 (UTC)

Exactly. This is not about "Global Warming caused by human actions", this is Global Warming. A climatic trend. And furthermore, you may provide links to "climate change" and all, but without elaborating the link, or identifying the concept, then there's no point, obviously you must place some easily accessable information, with drawing our the relevant points from climate change. Its just as bad as the articles with mathematical proofs that go "construct polynomial ring R over field F" and providing a link to what a polynomial ring is and what a field is, but not explaining how they interact. In the same way, just linking to Climate Change isn't sufficient, either. Weaken the information? An encyclopedic article discusses BOTH sides (or all sides if they are more), of the issue at hand. How is it clutter? Is it suddenly, clutter, because *gasp* it detracts away from the main ICC argument? Obvious tactic, skeptic allies? I smell a troll. -- Natalinasmpf 18:22, 22 Apr 2005 (UTC)

Cortonin, have you read the first paragraph of the article? It appears you haven't. It is quite well defined, why don't you read it? You might discover what the article is about. Vsmith 20:44, 22 Apr 2005 (UTC)

The article discusses the theory that human causes cause artificial climate change. Point being? This makes it an argument - which of course there are (often solid) rebuttals to this theory which due to the NPOV policy, should be shown. -- Natalinasmpf 20:58, 22 Apr 2005 (UTC)

Vsmith, yes, of course I have. Global warming theories may attempt to account for an observed temperature fluctuation, but that is not the full scope of global warming. It is "a term used to describe an increase over time of the average temperature of Earth's atmosphere and oceans," and more generally, it includes a set of theories describing these temperature changes and the associated observations, predictions, and effects. Unless, of course, you think we should redefine it to "a term used to describe an increase over time of the average temperature of the Earth since the late 19th century and due to anthropogenic greenhouse gases." Wouldn't that do a wonderful job of solving the questions by defining everything you believe as fact. — Cortonin | Talk 22:34, 22 Apr 2005 (UTC)

It also isolates the variable. You may claim that global warming is due to the emission of greenhouse gasses in the last 150 years, but you have to isolate the variable to see its not part of a bigger pattern. I suggest keeping the graph. -- Natalinasmpf 21:53, 21 Apr 2005 (UTC)

questions about 2kyr graph

I've deleted the 2kyr graph, why is the year 2004 plotted even though it should be off the graph. Is the instrumental data decadally smoothed? How are the boundaries handled, especially the hockey stick end where only the black instrumental line appears.--Silverback 04:15, Apr 22, 2005 (UTC)

The x-axis runs 0 AD (or whatever you want to call it) - 2004 AD to accommodate the 2004 point, which is the single value for that year. The black line for the instrumental data is smoothed the same as everything else. The smoothed records are 5 years shorter at each end than the original data. Anything else? Dragons flight 04:53, Apr 22, 2005 (UTC)

Yes, how can the smoothed instrumental data be 5 years shorter than the original data and have a 2004 point? Also, how did you place the decadal smoothing relative to the year it is plotted, shouldn't you have used an odd number of points for your smoothing. What should the last plotted year be with your smoothing? If you "center" your 10 pt stencil on the year, you will have 5 pts on one side and 4 on the other. Which side is the 5 on? --Silverback 04:56, Apr 22, 2005 (UTC)

The 2004 point is simply the annual average for 2004, and is shown for a present day reference, if you want to add a comment to the caption about this, be my guest, but it hardly seems a reason to remove the whole plot. The smoothed record, which is shown as the dark line, ends in 1999. As noted on the image description page it is actually σ = 5 year Gaussian weighted moving average. In other words, if $T(t)$ is the Temperature record as a function of time then the average is given by

${\bar {T}}(t)={\sum _{k=t_{o}}^{t_{max}}T(k)*e^{-(t-k)^{2} \over 2\sigma ^{2}} \over \sum _{k=t_{o}}^{t_{max}}e^{-(t-k)^{2} \over 2\sigma ^{2}}}$

As you will note, ${\bar {T}}(t)$ actually is defined for all times t and uses the data T(t) at all measured times in determining the average. However, because the Gaussian is a rapidly varying function of k, it is mostly determined by k in the interval [t-σ,t+σ], and it is usually considered reasonable to report the averaged values to within σ of the end of the record. Dragons flight 05:37, Apr 22, 2005 (UTC)

So approximately 68% of the weight is within an 11pt stencil centered the year being calculated. I wonder what happens when it runs into the end, is something reasonable assumed for the 16% of the weight that gets lopped off at. I am going to self revert, and place a comment in the caption. If you redo this to incorporate later analyses, it would be better not to mix individual data points with smoothed data.--Silverback 08:08, Apr 22, 2005 (UTC)

I disagree with respect to the 2004 point. A reasonable person can conclude whether or not it is likely to be consistent with a continuation of the trend. A sceptical person can go look at the other plots and decide whether 2004 is an anomalous outlier (I would say it is not). In my opinion it is more useful than confusing, however I have added a note about that point to the image description page. Dragons flight 13:57, Apr 22, 2005 (UTC)

That is what is deceptive about the graph, the 2004 point looks consistent with the trend because of the compressed time scale, even if the 2005 is even higher, the smoothed curve will pass below that 2004 point, and since the black line is based on unadjusted raw data, it probably should not even be on the chart, even if it was used to scale the other data.--Silverback 21:13, Apr 22, 2005 (UTC)

SB, I'm not clear what you are objecting to when you say the black line shouldn't be on the chart. As far as whether or not 2004 is consistent with the trend, I just ran the following test: I fit a line to the black curve from 1980 to 1999 and asked what value it would project for 2004. The difference between that and the reported value for 2004 is a tiny 0.005 °C (with the line being below the point). However, 0.005 °C is basically a rounding error when it comes to climate. Had it been an El Nino or La Nina year in 2004 you could get deviations of 0.1 °C. Obviously, this is just one test, and a fairly arbitrary one at that, but in my opinion there is nothing about the 2004 data point that is inconsistent with the long-term trend. Dragons flight 22:08, Apr 22, 2005 (UTC)

(William M. Connolley 20:05, 22 Apr 2005 (UTC)) And lets not forget that 2004 isn't the maximum value, just the most recent year.

Edit 4.249.186.129

I disagree with the edit done by 4.249.186.129. I think the phrase "The current scientific consensus on global warming" is closer to the true condition versus "The majority view on global warming".

Question for a reference

Would it be sensible to cite Michael Crichton's book State of Fear as a reference for reading? I recently read the book, and although its sci-fi attributes lean more to the fictional genre more than the scientific, Crichton did some pretty extensive research, as displayed in the book's bibliography. OK, so I'm adding it. If anyone cares, you can sue me or just remove the edition. =) Regards, Salva 20:28, 25 Apr 2005 (UTC)

(William M. Connolley 15:55, 26 Apr 2005 (UTC)) Anyone can quote references. SoF contains wild distortions and isn't suitable for use as a reference. See http://www.realclimate.org/index.php?p=74 if you want some details.

I give up - it is still biased

Quote: "The current scientific consensus on global warming might be summarized by the findings of the Intergovernmental Panel on Climate Change (IPCC). In their Third Assessment Report, they concluded that "most of the warming observed over the last 50 years is attributable to human activities".

I did not know there is a concensus now.

(William M. Connolley 10:30, 28 Apr 2005 (UTC)) What do you mean? That you didn't know there was a consensus, but having read the article you realise there is?

http://www.envirotruth.org/news-cosmic.cfm

Dr. Tim Patterson, a professor in the Department of Earth Sciences at Carleton University, who specializes in Paleoclimatology wrote this artical. If you review Tim's course then you will find that he also talks about orogenic processes, ocean current processes and so forth.

(William M. Connolley 10:30, 28 Apr 2005 (UTC)) Which is why its not very relevant to whats here.

What I might suggest is that this artical be spilt in two. Rather than having revert wars - write an intro an in there talk about the controversy then let each faction post their views with the understanding that faction "CO2" cannot edit the other faction's page and visa versa.

(William M. Connolley 10:30, 28 Apr 2005 (UTC)) Perhaps you think it might eb agood idea to have an article about the global warming controversy?

There is also a page on Paleoclimatology and I for one do not want any climate change people mucking with it. The basic reason is the climate change people are looking at say the last 2,000 years and certainly not much past 2 million years. Paleoclimatoloy is focused on a time scale of 4.5 billion years with particular interest in the last 570 million years because we have more data.

This is like having the enclopeadia Britannica which has 19 books. If each book represents 30 million years years then each page is about 30,000 years. On this scale each line represents about 190 years. This means our climate change folks are looking at the last 5-10 lines of the last page of the last book.

As a paleoclimatologist, Patterson says the geological record does not support CO2 as a climate driver. This does not mean CO2 has no effect... it clearly will have an effect. However the effect can be minor. Defining Global Warming as that portion of change attributed to humans does not change the fact that the effect of CO2 can be lost several digits behind other factors such as changes in water vapour (caused by massive irrigation).

(William M. Connolley 10:30, 28 Apr 2005 (UTC)) This is nonsense, for reasons that have been explained: did you bother read them?

Connelly has incorrectly argued that since water vapour comes out of the atmosphere quickly it cannot be responsible for climate change. Yet - we have entire rivers forced itno the atmosphere and this constantly renews water which falls out - that mechanism is via plant transporation and evaporation and this occures in arid areas.

(William M. Connolley 10:30, 28 Apr 2005 (UTC)) No, clearly you didn't.

If we contrast the climate at the top of Mount Everest to that of Brisbane Queensland for instance, then we can see that it is warm and muggy in Brissy and cold and dry at the top of Everest. N2, O2, and CO2 are in the same relative porportions and indeed they collectively account for only about 25% of the absorbtion at sea level of incident solar energy because the solar constant measured in space is 1300 watts per M^2 and at sea level it is about 1000.

What is hugely different is the atmospheric pressure and even more important is the fact that in Brisbane at above 35C we can expect to have about 40,000 PPM of Water Vapour while at the top of Everest we have less than 1000. Check the [dew point] curves for this.

If the data collected by Dr. Jan Veizer and Dr. Nir J. Shaviv ( see the artical http://www.envirotruth.org/news-cosmic.cfm ) is correct then the earth might be coming out of the ice age we are in.

(William M. Connolley 10:30, 28 Apr 2005 (UTC)) Which would be incompatible with the temperature record.

OTOH we might still just be in an interglacial. In all likihood these processes are geological in nature and there is nothing we can do about them - other than start rebuilding some mountians (Orogenic processes correlate well with ice ages). If we are in fact in an interglacial then any warming will just push off the cooling for a few 100 years and in this case maybe it will give us time to put mirrors in space - without which we might find NYC under a mile thick glacier.

I see no problem with the global warming folks spouting. However this artical is a bad one because it is biased and it has not been getting better. So I suggest - agree to disagree and write two articals. To avoid the revert wars the admins can freeze approriate pages for appropriate folks.

Terrell Larson

Shaviv & Veizer

Cortonin recently added reference to the Shaviv and Veizer work suggesting upper bounds on the impact of CO₂ doubling. I agree that this is interesting work, but it is not appropriate to this page because it is not relevant to the time scales of present global warming.

From the cited paper, page 6: "As a final qualification, we emphasize that our conclusion about the dominance of the CRF over climate variability is valid only on multimillion year time scales."

And the same authors in Eos (Vol. 85, No. 48, 30 November 2004) make the stronger statement that without long-term ice sheet feedbacks, a response of 1.5-4 °C was a plausible result of CO2 doubling.

Many environmental groups latched onto to Shaviv and Veizer numbers as a reason to doubt the IPCC, but even Shaviv and Veizer don't believe that is the case because their work only applies to very long-term changes occurring in equilibrium with changes in continental ice sheets and geologic processes. The 2003 work does not constrain the temperature changes that CO₂ may cause over the next few centuries.

Dragons flight 14:35, Apr 28, 2005 (UTC)

Read the next sentence too. "At shorter time scales, other climatic factors may play an important role, but note that many authors (see previous references) suggest a decisive role for the celestial driver also on multi-millenial to less than annual time scales." Yes, the study only proves the connection on the multimillion year time scale, since this is where the dataset which can be worked with in such a way is, but they clearly follow up by saying that the strength of the mechanism is expected to similarly apply to scales as short as less than a year. And throughout the rest of the paper they are using the data to analyze the CO2 doubling models, specifically referencing the IPCC (example, fifth page). If you dispute that usage, publish on it, and we'll add your dispute. Re-adding. — Cortonin | Talk 18:12, 28 Apr 2005 (UTC)

Cortonin, I don't object to the material you are trying to include but I think I am going to try to refactor it and try to convey it more accurately and in context. For one thing, this isn't the best topic to be the focus of the "solar variation" section, since the comparison they are making is between temperature and cosmic ray flux as controlled by the passage of the solar system through the galactic spiral arms. Obviously cosmic rays are influenced by solar variation as well, but that is seperate from most of what Shaviv and Veizer (2003) are discussing. Also, the current text makes it sound like it is their model for interaction between cosmic rays and clouds, when they are in fact building on the work of others. You probably also need to note that their long-term temperature records are only sensitive to low-latitude temperatures and they say in the paper that figures probably need to be increased by a factor of 1.5 when comparing to global averages. Lastly, I do think the context of hundreds of millions of years matters. It is what all the numbers are based on, and even the authors say (i.e. the above cited Eos) that short-term variations in response to CO₂ could be considerable larger. (Oh, and I wouldn't need to publish that dispute myself since in addition to the authors own statements, Rahmstorf et al. and Royer et al. have already argued the point that the short term response to CO₂ increase may be significantly larger than the long-term glaciological / geological equilibrium responses Shaviv & Veizer may be measuring.)

Okay, that is a lot of caveats, which is part of why I am writing it here before making changes to your text, so that the reasoning is clear. However, I am also thinking about significantly rearranging this. I think I would like to move much of the detail to solar variation or solar variation theory, but leave a short reference to it and probably add some other solar variation work (Svensmark maybe) in the "Solar Variation" section of global warming. At the same time, I am thinking of trying to figure out a way to more directly seperate out the IPCC view of climate sensitivity and contrast it with minority scientific opinions, of which this could be an example (with a million years caveat). Anyway, I've not quite decided what I want to do, or how I want to go about it. I probably won't be doing anything elaborate before this weekend, so if you or others want to comment or make changes in the mean time, go ahead. Dragons flight 21:53, Apr 28, 2005 (UTC)

Well, there are two things of importance. First, it's not that they're attempting to measure the CO₂ response in the paleoclimate data (in fact, they try this and report that it doesn't work), but instead, that they're using the calculated solar sensitivity and associated feedback (which should scale down to smaller scales) to estimate the amount that could still be attributed to CO₂ given various models. There is a subtle, but important, difference between the two. — Cortonin | Talk 00:53, 29 Apr 2005 (UTC)

In your text in the article and here, you keep referring to this as "solar". You are aware that Shaviv and Veizer's work is not a study of solar variability, right? It has clear implications for cosmic ray changes as mediated by solar variability, but what they are looking at is the change in cosmic rays driven by processes external to our solar system. As a result one needs to be a little careful in how this work is described. Dragons flight 08:02, Apr 29, 2005 (UTC)

They are only partly looking at changes due to factors external to the solar system (most of which would not scale down to small time scales), and calculate that this accounts for a good portion of the large scale change. But they also spend a bulk of the paper discussing the effect due to solar wind shielding of cosmic rays and its effects on cloud formation, so this is directly related to output coming from the sun, and thus is "solar". It is this solar wind aspect which also varies on the short time scales (perhaps even more than on the large). — Cortonin | Talk 10:15, 29 Apr 2005 (UTC)

My reading is that they spend the bulk of page 2 (journal page 5) and a little bit of the conclusions discussing evidence for short-term connections, which provides context for their work, but the analysis itself is all long-term external perturbations. I think the right way to discuss this aspect of the work is basically the way they do, you say what it is they measure (i.e. external pertubrations of CRF relative galactic motions) and then say, as they do, that this has obvious analogs to short time scale processes. But it is not really okay to say that they have measured the impact of solar variability, since solar variability is not part of their data set and includes things like irradiance and UV variations that wouldn't be reflected in galactic processes. For the record, solar variability over the 50 years of good cosmic ray records, shows up as about a ~15% modulation (depending somewhat on where you are and what you measure). If their model is correct, then galactic processes modulate the flux over about a factor of 3. Of course temperatures also vary much much more over long time scales than over short, so not really a problem for the work, but just a comment that the effect of solar variation is scaled down compared to the effects for galactic motion. Dragons flight 14:55, Apr 29, 2005 (UTC)

Well they don't need to use a solar variability data set for the longterm, because what they're measuring on the longterm is the strength of the CRF feedback by comparing the levels of CRF (without regard for what causes them) in correlation with temperature fluctuations. The idea is then that the strength of CRF feedback on temperature by affecting cloud formation should be essentially the same in the shortterm, and the effects of solar wind on CRF can be determined from more recent data. — Cortonin | Talk 19:25, 29 Apr 2005 (UTC)

Second, I oppose the exclusion of solar variation theories from this page. According to most recent papers studying climate response due to solar variation, at least half of all observed temperature changes in the 20th century can be attributed to solar variation, and maybe more with certain feedbacks such as this. Shuffling this off to another article makes no sense. The page is not called "anthropogenic global warming". So whatever changes you make should still include a description of the basic principles of solar variation theory, along with the basic principles of the major feedback mechanisms involved with solar variation. I think, as you suggest, it would be good to get more detail here on other solar variation work, for a little diversity. — Cortonin | Talk 00:53, 29 Apr 2005 (UTC)

I also favor having reasonable mention of solar variability, but generally would prefer to avoid having the details of any single study on the global warming page itself. Dragons flight 08:02, Apr 29, 2005 (UTC)

Besides, even if it WAS called "anthropogenic global warming", the article has to NPOV and include arguments from all sides (with the appropriate dialogue), and just because the ideal theory would be ruined by an argument concerning another time frame doesn't mean its irrelevant. The IPCC theory would be ideal for the suited time frame, not accepting any arguments that doesn't deal with that is just plain silly because that's merely giving the IPCC argument an uncalled for advantage. If there is an argument that contests the validity of the time frame, you can't use the same time frame to try to rebut that argument or reject it. That would be circular logic. For example, if I was defending someone who was accused of murder because he was in such and such area at a certain time, but suppose I bring in evidence showing that the murder took place say, later in the day than thought. You can't reject the evidence on the basis of a "wrong time frame", because the very evidence contests the time frame. This applies for the IPCC versus upper limit on CO2 impact argument. Or if I bring in evidence that say, the murder victim was previously harassed by loan sharks, and thus the accused isn't the sole suspect, that evidence can't be rejected by that it was in the "wrong time frame". What the prosecution can do is argue whether the loansharks are capable of murder, etc. or were present based on their past records, which is equivalent to a full analysis of whether the patterns recorded are say, strong enough to manifest themselves again to offset previously predicted warming. I have not seen this discussion, only "wrong time period" arguments, which is completely off target, IMHO. -- Natalinasmpf 02:21, 29 Apr 2005 (UTC)

Please don't be hostile. In this particular case, everyone agrees that there are processes that occur over hundreds of millions of years that simply don't happen on the scale of a century (e.g. ice sheet responses, mountain building, changes in ocean chemistry, etc). Because of this, some scientists argue that Shaviv & Veizer's work has absolutely no relevancy to modern changes. Others, including the authors themselves if I am understanding them correctly, argue that it may have some relevancy to modern changes, but are cautious to note that the actual effect on short time scales might be considerably larger then they estimate.

In general, there are many cases of climate changes that have occured over long timescales which in my opinion are fairly well understood, and if the generally accepted arguments are accurate then they can't occur over the scale of a century. So yes, it does occur over the wrong time scale. But I'm not saying that because I have some inherent objection to looking at longer time scales. Frankly, I like context. But when you look over very long time scales you also observe a variety of features which, according to widely accepted science, simply can't be occuring over the time scale of recent warming. For example, if you look at Shaviv & Veizer, they argue the biggest climate signal is related to encounters with galactic spiral arms, which (in their model) are seperated by 140 Myr. Obviously, that part of the work, based on our position relative to the spiral arms, has not significantly changed in the last 150 years. (Cortonin and I both know this, and the present disagreement is over how to describe and how much relevance to give the other parts of the work.) Dragons flight 08:02, Apr 29, 2005 (UTC)

But the point is the dampening of the impact of the CO2. I mean, in many studies, the rate of CO2 increase versus the rate of temperature increase is hardly linear. I'm not being hostile, I'm just emphasising a fact in an otherwise long post. Natalinasmpf 10:43, 29 Apr 2005 (UTC)

And over long time scales you have other greenhouse gases, solar variations, galactic motions, ice sheet growth, mountain building, ocean circulation changes, orbital variations, etc., etc.. It is hardly surprising that one should look at raw data of CO2 versus temperature and find that there is not a 1-1 relationship, so you have to look at the studies that try to pull apart the myriad of different forcing factors. Many of these produce estimates for CO2 forcing that are consistent with IPCC estimates. Some, like Shaviv and Veizer, end up with lower values. Is that because there exists other negative feedbacks that occur on long time scales and haven't been accounted for? Even the authors are prepared to admit that possibility. With the current work, there is also the question of how well we know CO2 over that time scale. If you pay attention to their figure 1, they show three reconstructions of CO2, none of which really agree with each other. This work provides a point of reference, but one which may be buried under a lot of confounding factors. I don't object to using that point of reference in it's accurate context, but one should be respectably cautious about using very long-term records, which we don't understand all that well, to overthrow the shorter-term measurements that are much better documented. Dragons flight 15:21, Apr 29, 2005 (UTC)

The problem is of course that the short term records are short, and thus, there's much less that can be experimentally known about the precise response to certain climate stimuli. Simulations of complex systems don't give us anywhere near the accuracy of experimental observation, so to examine global warming based primarily on simulations without careful examination of the best data sets available would be a critical mistake. Certainly, using longterm trends to examine shortterm trends merits caution and consideration of scale-dependence of the mechanisms, but using simulation to replace experimental observation requires at least as much, if not more, caution. A thorough examination has to consider both. — Cortonin | Talk 19:01, 29 Apr 2005 (UTC)

Part 2

I have removed the reference to the clouds, cosmic rays, climate mechanism primarily because you are misappropriating it to Shaviv and Vezier. They did not propose this idea. Their work was motivated by the work of Svensmark, Marsh and others (e.g. [5] [6] [7] [8]). Shaviv and Vezier are relatively late comers to this debate. Their work supports this connection, but there is nothing about the short-term connection that is new to them. If there is a discussion of this particular mechanism it seems to me that it should probably appear in the solar variation section and be attributed to one (or more) of the original proposers and not to Shaviv & Vezier, who in this respect are primarily quoting other people's work to motivate the context of their own work. Dragons flight 05:31, May 2, 2005 (UTC)

Very well, so it could be described with detail in the Solar Variation section in the wording of the earlier researchers in that area, but it should still have a brief mention in the S&V section whether or not they originated it. It's an important part of their justification for the extension of the work to shorter timescales (since we don't go in and out of galactic arms on a daily basis), and it makes no sense to follow up with a criticism of the applicability to shorter timescales unless the mechanism for extending it to shorter timescales is first summarized. — Cortonin | Talk 05:37, 2 May 2005 (UTC)

But it is the relevance of the CO₂ calculation to short time scales that is being debated. I agree that their conclusions support the importance of cosmic rays on short time scales, but whether or not their CO₂ calculation works on short time scales seems to me to be an independent question. Dragons flight 05:44, May 2, 2005 (UTC)

But their calculation of CO₂ requires only that the cosmic ray calculation be correct. They are making the maximal assumption that all variance not explained by cosmic rays is attributed to CO₂, thus giving an upper bound for CO₂ contribution. So if their calculation for cosmic rays is correct, then their CO₂ calculation should also be correct. Of interest, is that the authors of the critical essay were complaining because S&V didn't include methane. But by the reasoning S&V used, including methane could only reduce the contribution due to CO₂ from that calculation, since the leftover would then have to be attributed to CO₂ and methane, when instead they were attributing everything leftover to CO₂. — Cortonin | Talk 19:04, 2 May 2005 (UTC)

WikiProject Climate Change

Shouldn't there be a WikiProject Climate Change to help coordinate the various articles around the topic? Also, I suggest that it would be worth trying to create a simple entry page aimed at laymen with no knowledge of the subject, sans confusing detail and too many references. Maybe Global warming and Global warming (advanced) - that kind of concept anyway. It would really be useful to have a more stable, easier overview, and keep the discussion of the developing scientific details a little bit tucked away. Take a minute to think about the average reader, people. Rd232 09:04, 4 May 2005 (UTC)

Wouldn't it be nice! But with such polarised views and with each side minutely inspecting the other's contributions, and (rightly) insisting on citations, I'd be very surprised if any summary would survive a deluge of edits. There seems to be such strong disagreement even on the underlying approach the "Global warming" article(s) should adopt. See, only as a sad example, Wikipedia:Requests for arbitration/William M. Connolley and Cortonin. Thincat 10:35, 4 May 2005 (UTC)

Worth a try though. I do think since much of the disagreement is about detail, it should be possible to summarise the general issues in a moderately non-controversial way. Does the average reader really want to go straight into scary graphs and discussion about recent data on the effects of urban heat islands? Or be faced with paragraphs like this: A new reconstruction by Moberg, et al, published in Nature 433, 613 - 617 (10 February 2005) [9] shows both the Medieval Warm Period and Little Ice Age anomalies (although not by name) and concludes that the temperatures around 1000 and 1100 AD were comparable to those of the 20th century before 1990. "Moberg's reconstruction will help to put the record straight in one of the most contested issues in palaeoclimatology," says Hans von Storch. "But it does not weaken in any way the hypothesis that recent observed warming is a result mainly of human activity." [10]. Moberg's results are consistent with those of Von Storch, et al, who conducted a modeling analysis that showed the variability to be about twice as great as previously published [11]Science 306, 679 - 682 (2004) (http://dx.doi.org/10.1126%2Fscience.1096109%7C). Rd232 17:15, 4 May 2005 (UTC)

(William M. Connolley 19:57, 5 May 2005 (UTC)) A wikiproject on this might well be a good idea, the articles are probably a maze for the newcomer. I have been advocating shortening the GW article for some time now: in my view it is prone to "stuffing" by the skeptics (see the recent S+V stuff). But, this will be hard to accomplish in the current state, and I think we're all waiting for the arbcomm to see if they provide anything useful to help resolve the dispute(s). OTOH I would argue that much of the current article is quite good, and at least up to A new reconstruction by Moberg... not too detailed.

Temporary injunction

Copied here from Wikipedia:Requests for arbitration/William M. Connolley and Cortonin#Temporary injunction:

Since revert wars between the Cortonin and William M. Connolley have continued through this arbitration, both users are hereby barred from reverting any article related to climate change more than once per 24 hour period. Each and every revert (partial or full) needs to be backed up on the relevant talk page with reliable sources (such as peer reviewed journals/works, where appropriate). Administrators can regard failure to abide by this ruling as a violation of the WP:3RR and act accordingly. Recent reverts by Cortonin [12] [13] [14] [15] [16] by William M. Connolley [17] [18] [19] [20] [21] Additional reverts by others involved in these revert wars may result in them joining this case.

--mav 22:44, 23 May 2005 (UTC)

RealClimate.org discussion

I'm re-inserting the realclimate.org reference as a discussion and critique of the paper at Envirotruth.org [22] as well as the published Nature article. Seems appropriate to me. Vsmith 16:24, 24 May 2005 (UTC)

Shouldn't we in turn have a reference to a similar discussion and criticism of the Oreskes paper? After all, it's pretty easy to check that Oreskes paper does not actually describe the 928 abstracts which result from looking up "climate change" as she claims in the paper, and there are valid criticisms about the subjectivity of assessing the degree of support in the abstract. — Cortonin | Talk 20:33, 24 May 2005 (UTC)

(William M. Connolley 22:11, 28 May 2005 (UTC)) Its not clear what you mean by Oreskes paper does not actually describe the 928 abstracts which result from looking up "climate change" as she claims in the paper. It doesn't sound true: why not provide a ref.

Hey V, perhaps you'd care to explain why a blog is a valid source to criticize a peer-reviewed article. I mean, it seems pretty lopsided to me - rather like using extracts from the editorial page to refute something on the front page. Shouldn't we steer clear of the "apples and oranges" comparison here? Sorry, but "seems appropriate to me" isn't really a good enough reason to put opinion on the same level with scholarship. --JonGwynne 06:11, 25 May 2005 (UTC)

(William M. Connolley 22:11, 28 May 2005 (UTC)) Your understanding of the literature is unnuanced.

What happens to GW when 2005 is colder

2005 is on track to be colder than 2004. All the graphs will then have a spike at 03/04 and drop down again, this will also bring the 5 year moving average down. Will this year be dismissed at an outlier? If so, what happens if 06 is more on par with 05 than 03/04. Still an outlier? Everyone gets really upset when talking about the statistics involved and what points are considered valid data, I'd rather those people not comment, I'm more interested in what actually happens. Will several years of cold weather sink GW theory? I'm familiar with the graphs which are visually convincing, but clearly the El Nino spike is responsible for some of the observed variance. As this influence subsides the graph will drop back down, and although may still be rising at a smaller rate, I wonder where this discussion will be in 5 years. Facts have the unfortunate tendency of dictating what theories do and do not survive. Personally I'm nihlistic about GW as I live somewhere where the Avg Temp is 90-105 in the summer yet somehow the ecosystem is vibrant. I do however find the GW discussion (argument/flamewar?) interesting. It has become an object of faith on the left and scorn from the right. I'd appreciate hearing what the GW proponents think will happen if 05-06 is cold relative to the last 5 years.

Also I read the article on climate and laughed. It's defined on a time scale ranging from (no joke) months, years, thousands of years, millions of years. There are several powers of ten differences there. How can climate change be defined when the big proponent of it can hardly nail down the definition of climate. Anyways I look forward to hearing what you guys think about the 05 cold.

--Dsquared 00:45, 1 Jun 2005 (UTC)

Global warming is about average temperatures of long periods of time. So what happens in one year is really inconsequential. It's a misperception that global warming means that all of a sudden it'll be 90 degrees in the winter all the time: even a very small increase in average global temperature will have disastrous effects and that's what the data predicts, despite variations in this trend over very small periods of time. Because of the aformentioned misperception, you're quite correct that people not familiar with the theory beyond the two words "global warming" - i.e. most people attempting to debate the topic from my experiences - will be swayed to deny it. --Tothebarricades.tk 02:19, Jun 1, 2005 (UTC)

Ah, and so I must ask what constitutes a long period of time? Five years, 20 years, why not 100 years or 1000? The earth is 4.6 billion years old, humans have been creating co2 for less than 300. 300 years doesn't sound like a long period of time when speaking in geologic time periods. 100kyrs aren't even very long geologically. The anthropogenic argument relies of defining 'long period of time' at less than 300 years which is really a blip on the lifespan of the earth. Yet the models predict .xx degrees warming by 20xx. I remember when they were saying that by the year 2000 the temperature would rise 1.8 degrees or whatever silly amount it was. That didn't happen but now they are dropping the amount of warming by factors of 10 and raising the rhetoric by a similar amount. You argued that what happens in one year is inconsequential, by that same reasoning you could argue that what happens in one decade or one century is inconsequential. Statistics requires a large sample to return valuable results and only results that predict at what rate a certain outcome would occur over many possible tests. You have to poll nearly 1,000 people to get statistically significant results yet averaging temperature over less than 300 years is claimed to be statistically significant and capable of predicting future outcomes with certainty to within one one-hundreth of a degree. I'm not trying to troll or anything but I believe that I've never gotten a satisfactory answer to these questions even from die-hard GW proponents and I can't understand how a theory can be so widely accepted if noone can answer these fairly simplistic questions.

--Dsquared 02:36, 1 Jun 2005 (UTC)

To call these questions simplistic is an understatement. When your comments aren't simplistic, they're simply wrong. To take one example:

I remember when they were saying that by the year 2000 the temperature would rise 1.8 degrees or whatever silly amount it was. That didn't happen but now they are dropping the amount of warming by factors of 10 and raising the rhetoric by a similar amount.

Here, you're saying that you "remember" something when clearly you don't remember much at all. For starters, who exactly do you mean by "they"? You claim that this vague anonymous "they" predicted a figure of "1.8 degrees" and then immediately admit that you don't remember what figure "they" predicted. Even though you don't remember who they were or what they said, you somehow think they were "silly" to say it. And since your memory of what "they" said is so vague, it seems presumptuous to say the least for you to claim that their prediction didn't happen. You then claim - completely falsely, I am quite certain - that this vague anonymous "they" are "dropping the amount of warming by factors of 10." I'm familiar with what climate scientists have been saying about the likely magnitude of global warming, and no one is dropping their estimates by "factors of 10." The current estimate for temperature increase by the year 2100 is estimated at between 1.4 to 5.8°C, which isn't much changed from past estimates - certainly not by a factor of 10.

To take another example, it's rare to see as many errors packed into a single sentence as you managed to produce when you wrote:

You have to poll nearly 1,000 people to get statistically significant results yet averaging temperature over less than 300 years is claimed to be statistically significant and capable of predicting future outcomes with certainty to within one one-hundreth of a degree.

• To begin with, you don't have to "poll nearly 1,000 people to get statistically significant results." The question of how many people need to be polled in opinion surveys depends on the size of the total population whose opinion you are trying to measure. And even for national opinion polls in the United States (which has a population of nearly 300 million), leading polling organizations such as Gallup routinely derive significant results from polls of fewer than 500 people.[23]
• Secondly, climate scientists don't simply rely on a single average temperature for the earth taken once each year. The earth's global surface temperature is itself a statistic derived from readings taken continuously from numerous sampling stations throughout the globe. Other climate research data comes from floating buoys that measure the temperature of the ocean, along with measures of various temperature proxies such as receding snowcaps on mountains. Climate researchers use highly complex models and datasets with literally millions of datapoints - not a mere 300 datapoints as you erroneously state. Your claim that their dataset is too small to produce statistical significance is false and merely demonstrates your ignorance about the way climate research is actually conducted.
• Finally, no climate researchers are "predicting future outcomes with certainty to within one one-hundreth of a degree." As I stated above, the estimate for global temperature increase by the year 2100 is estimated at between 1.4 to 5.8°C - a range of 4.4 degrees, which is a far cry from your absurd claim that they are predicting things to within .01 degree.

If you're having trouble getting "satisfactory answers" to your questions about global warming, I think this is probably because you know so little about the subject that you don't know how to ask meaningful questions. You clearly know very little about statistics, the scientific method or the specific science of climate research, yet you're full of blustery accusations and strongly-expressed opinions on these very topics. I doubt that many people would even bother to respond to someone who displays this little knowledge and this much attitude.

By the way, what's your basis for claiming that "2005 is on track to be colder than 2004"? I haven't seen any evidence to support this claim. (Not that it matters much. No climate researchers are presently claiming that their methods are precise enough to predict the variation from a single year to the next.) --Sheldon Rampton 07:13, 1 Jun 2005 (UTC)

So then you would be surprised by this New York Times article:

Temperature For World Rises Sharply In the 1980's New York Times, Mar 29, 1988

"... Mathematical models project that at the current rate of buildup of the gases thought to cause the greenhouse effect, the average global temperature will rise from the 59-degree base by 3 to 9 degrees Fahrenheit by about 2030, with increases substantially greater at the higher latitudes but lower increases near the equator. Dr Hansen said the temperature was increasing in this decade even as natural factors were keeping surface temperature lower than they might have been. These factors, he said, are relatively low radiation from the sun and high volcanic activity, which produces particles that tend to filter out some solar radiation. ..."

By my rough calculation that would mean .9 to 2.6 degrees by 2000. Sorry for having antecedent vagaries, but here you go, the NY times quoting Dr James Hansen of NASA on a 3-9 degree rise by 2030, or by right now (2005) a 1.2 to 3.6 degree rise.

I could come up with a lot more fear mongering than this. I picked this article as it is one of the earliest instances of predicting doom via global warming. I appreciate your ardent attack on me but now that I have indeed produced a 'they' and nailed down a prediction (.9-2.6) when I said 1.8, it looks like I picked a number smack in the middle of what was in fact predicted 17 years ago, you could apologize for assuming I was just making all of it up. If you want to see the article you can go to your local library, spend a couple bucks like I did at the nytimes website; it's easy search archives for "global warming" in 1988 and you'll see the headline. I have a PDF copy of it but I'm not sure of the legality of distributing it online but if you really dont believe it exists maybe I'll email you or post it online briefly.

You say that the current prediction "which isn't much changed from past estimates - certainly not by a factor of 10". The prediction I quoted was nearly the same temperature change except in 88 it would happen by 2030, whereas now it won't happen until 2100. You're right it's not a factor of 10 but it is nearly triple (2.67) the original time frame (112 years to achieve said change versus 42 years) If you think that's not a lot of change I'm not sure what is, except maybe in another 17 years the figure will be adjusted upwards to 2150 or 2200, who knows.

And that is exactly my point. We don't know and claiming certainty about the changes and time frames involved is a fool's errand going back at least 17 years. You may absolutely be convinced that it is happening but remember that so was everyone else nearly 20 years ago.

Please refrain from attacking someone because they dare question the vaunted scientific consensus of the day. Remembering is tough stuff and frequently makes a lot of smart people look foolish but the cost of forgetting is a lot more expensive then spending a few bucks to see what the ever elusive "they" were saying in the not so distant past.

--Dsquared 09:27, 1 Jun 2005 (UTC)

No, I'm not surprised by the NY Times article, and I don't owe you an apology. You've misrepresented the NY Times article. The third paragraph of the article, which you omitted, states:

In interviews, meteorologists and others engaged in plotting global climate trends were cautious about blaming the greenhouse effect for the recent sharp increase, saying mathematical models of the phenomenon project much sharper increases than have so far occurred.

The article then goes on to quote Dr. Hanson saying what mathematical models predict for 2030, while other scientists caution that the level of scientific knowledge is still insufficient to make definite predictions and that perhaps "the models are more sensitive than nature." They add, however, that if "the next 10 years are as warm or warmer, it would be very hard to deny the greenhouse effect." This is, of course, exactly what has happened.

In 1988, climate science was less developed than it is today, and a number of leading researchers (some of whom are quoted in the NY Times article) readily admitted that the data was not yet sufficient to say with confidence that global warming driven by human greenhouse gas emissions was actually happening, let alone predict the magnitude of that warming. They had mathematical models, but they didn't know how well those models actually fit reality. Since then, considerable new data has accumulated, and the models have also improved, which is why scientists like Thomas Karl (who is quoted in the NY Times article expressing skepticism about global warming) have changed their assessment. Global warming skeptics used to love quoting Karl, but they don't quote him anymore. He now says, "There is no doubt that the composition of the atmosphere is changing because of human activities, and today greenhouse gases are the largest human influence on global climate."[24]

Even so, however, no one is claiming that they can predict variation from one year to the next or that they can predict to within .01 degree, as you falsely wrote previously.

--Sheldon Rampton 16:34, 1 Jun 2005 (UTC)

Well, right as I press the insert Signature Timestamp button some idiot runs into a power line and the computer goes dark. Let's see if I can give you the short version of what I wrote.

• I say that dire predictions regarding GW have been promoted by 'they' and that it hasn't happened.
• You say that since I lack specifics I must be making it all up and that youre quite confident I won't be able to produce any references
• When I do you point out that I didn't bother to transcribe the entire article by hand and that near the bottom of the article there is someone who doesn't agree with the dire prediction but now currently believes in GW and that you don't owe me an apology for insinuating I was making it all up.

You don't have to apologize, but it's intellectually dishonest not to.

• "it seems presumptuous to say the least for you to claim that their prediction didn't happen"
• "I think this is probably because you know so little about the subject that you don't know how to ask meaningful questions."

I produced a prediction that didn't come true and the number I was remembering, 1.8, was in the middle of the values that were predicted for 2000. You claimed that I wouldn't be able to do this and then attacked me personally and refuse to admit that you were wrong. I don't know who these scientists are and furthermore I don't care. The media has been pushing the dangers of GW for years all the while the scientists predictions of the warming are dropping. I produced facts to back this assertion up and you ignored them, by stating that the very same article mentioned people that didn't agree with the methodology. So now we are hearing about a specific global warming prediction by 2100 instead of 2030, you don't have to be a PhD to understand the predictions have moved back further in time effectively dropping the decade on decade warming rate. This happened, you said it didn't and refuse to apologize for saying I didn't know what I was talking about. I said the scientists were wrong back then and you denied it and then when I produced evidence defended your previous comments by saying the scientists were wrong back then....

I've already repeated myself enough I don't feel like making any snide remarks.

--Dsquared 22:12, 1 Jun 2005 (UTC)

"Well, right as I press the insert Signature Timestamp button some idiot runs into a power line and the computer goes dark." Based on the available data, we can now predict that your computer will lose power approximately one-fourth of the time that you click on the Signature Timestamp button. (SEWilco 03:30, 2 Jun 2005 (UTC))

---

Reply to Dsquared: First, you didn't produce "a prediction that didn't come true." You produced a news story in which Dr. James Hansen mentioned that a mathematical model projected a certain result by the year 2030. There's a huge difference, for starters, between projecting a result for the year 2030 and projecting a result for the year 2000, which is what you claimed. You basically invented a prediction for the year 2000 by assuming that Hansen's model projected uniform increases each year (a false assumption), and using that false assumption to calculate what you think Hansen's model should therefore have predicted for 2000. Since Hansen's model didn't project uniform increases each year, your fabricated "prediction" is nonsense.

You accuse me of "intellectual dishonesty," but if you really want to know what Hansen's model was projecting in 1988, the honest thing for you to do would be to look it up instead of inventing numbers. The results of Hansen's computer modeling can be found in a paper titled "Global climate changes as forecast by Goddard Institute for Space studies three-dimensional model," published in 1988 by the Journal of Geophysical Research. Here's the abstract of Hansen's paper. It states that the modelers made "a 100-year control run and perform experiments for three scenarios of atmospheric composition." Note that the researchers used three scenarios, not one. This is because they knew that it was impossible to forecast the actual amount of greenhouse gas emissions that would be added to the atmosphere in the years following 1988. One scenario therefore assumed continued "exponential" growth in emissions; another assumed "linear" growth; and the third assumed a "rapid curtailment" of emissions. If you want to see how those scenarios match up against what has actually happened circa the year 2000, Hansen has prepared a chart (which you can view here) showing how the three scenarios match up against actual observed temperature change. The observed temperature change turns out to be lower than scenario A (based on exponential emission growth), but higher than scenarios B and C in his model. (For a more extended discussion by Hansen of how his 1988 work figures in the global warming debate, here's something that he wrote himself.) In short, his modeling was actually pretty accurate.

You seem, moreover, not to understand the difference between saying that a mathematical model projects something and saying that scientists predict something. Mathematical models are one of the tools that scientists use to study natural phenomena, but they are not prophecies. Science works by proposing hypotheses (typically formulated in mathematical models), comparing those hypotheses against actual empirical data, and then revising the hypotheses based on the empirical results. The scientists quoted in the NY Times article you cited from 1988 knew perfectly well that the mathematical models didn't match up with the empirical data, and they said so at the time. Hansen's paper, in which he published the results of his computer modeling, also acknowledged uncertainties, which is why he used three different scenarios. Other uncertainties noted in his paper included "the equilibrium sensitivity of the model to climate forcing, the assumptions regarding heat uptake and transport by the ocean, and the omission of other less-certain climate forcings."

In short, the facts are contrary to what you've written. Hansen didn't "predict" an outcome for the year 2030; he ran some projections, and he stipulated at the time that those projections were subject to uncertainty. The only near-certainty that he expressed in 1988 was when he said he was 99% certain that human-induced global warming was indeed occuring. However, he didn't claim to predict the magnitude of that warming by 2030, let alone by the year 2000.

His behavior as a scientist was far more responsible and less "silly" than your own behavior here, where you have simply invented facts and figures, presented other figures based on your own calculations relying on patently false assumptions, and compounded your errors by displaying a condescending attitude toward people who know more about this topic than you do. --Sheldon Rampton 03:46, 2 Jun 2005 (UTC)

---

What of the theory that global warming will lead to an increase in water vapor which will make the earth's temperature more uniform, i.e. hot places colder, cold places warmer, but generally the earth will be warmer overall? I assume that global temperature figures are adjusted for the lattitude and climate where all the readings are taken? zen master T 22:23, 1 Jun 2005 (UTC)

Models

No, not Miss Universe.

Sheldon you said something very profound without realizing it. Models don't claim to be able to predict future outcomes. They are merely a tool to study the natural world.

Why then in all seriousness does the Kyoto Protocol exist? We can both argue until we are blue in the face about whether humans are responsible for warming; but why does this huge intergovernmental treaty exist seeking to cap CO2 emissions from first-world countries. Why put this huge economic weight on the world economy when by the IPCC's own admission won't stop the warming and may only slow it down?

And all of these predictions are based on models with major deficiencies....

I for the life of me don't know why everyone got so upset when Bush killed Kyoto in the US.

--Dsquared 06:13, 2 Jun 2005 (UTC)

Models cannot predict future outcomes with absolute certainty. They can, however, make predictions within some confidence interval. If you model is able to predict the behaviour of a system, especially if it can make predictions outside of the data which were used to construct the model, you can be fairly conifident that the model describes the relationship and interactions between a set of parameters and variables. Since these models work with (broadly speaking) known relationships, you can make reasonable conclusions about the robustness and accuracy of any given model. These models are able to take "what if" scenarios (which are eminently reasonable, based on observed trends) and come up with predictions. Of course, they assume that certain relationships are either invariant or will change predictably.

As for Kyoto - the cost of Kyoto is a fraction of what the US currently spends on clean air laws. The idea that it's a "huge economic strain" is a fallacy. As for "why go with something that's uncertain"...would you rather deal with having to spend a few dollars making your industry more efficient, or would you deal with 17 million displaced Bangladeshis? If the predictions are accurate, then it is the moral responsibility of the country which produces 25% of the world's greenhouse gas emissions to handle 25% of the environmental refugees. Doing "too little" might mean that you reduce the number of displaced people from 50 million to 30 million. Is that worth the investment?

People pour billions of dollars into investments based on economic models which have far greater uncertainties than climate change models. Millions of people evacuate when models tell them that a hurricane may be headed their way. Do you take your umbrella when the weatherman uses models to say it will rain today? Or do you say "it's just a model" and plan your wedding for outdoors on a January day in Maine? Guettarda 06:33, 2 Jun 2005 (UTC)