Talk:Climate change: Difference between revisions
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I'm still in favor of restoring Stephan's "may have" qualification to the description of the singleton research paper which is the subject of this section. Africangenesis is raising interesting ideas, and I think we should write them up if they can be adequately sourced. First, though, if the relevant articles on climate modeling are out of date, we should improve them, then update this one to reflect their new content. --[[User talk:Tony Sidaway|TS]] 09:16, 20 October 2010 (UTC) |
I'm still in favor of restoring Stephan's "may have" qualification to the description of the singleton research paper which is the subject of this section. Africangenesis is raising interesting ideas, and I think we should write them up if they can be adequately sourced. First, though, if the relevant articles on climate modeling are out of date, we should improve them, then update this one to reflect their new content. --[[User talk:Tony Sidaway|TS]] 09:16, 20 October 2010 (UTC) |
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:In the past, wasn't ownership of this more prominent article partially maintained by insisting that details relevant to disputes and credibility of the scientific claims on this page, be pushed off to other specialized, less prominent pages, i.e., isn't disputing edits on this page on such a basis, "battleground behavior"? --[[User:Africangenesis|Africangenesis]] ([[User talk:Africangenesis|talk]]) 10:14, 20 October 2010 (UTC) |
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== Climate models == |
== Climate models == |
Revision as of 10:14, 20 October 2010
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Frequently asked questions To view an answer, click the [show] link to the right of the question. To view references used by an answer, you must also click the [show] for references at the bottom of the FAQ. Q1: Is there really a scientific consensus on climate change?
A1: Yes. The IPCC findings of recent warming as a result of human influence are explicitly recognized as the "consensus" scientific view by the science academies of all the major industrialized countries. No scientific body of national or international standing presently rejects the basic findings of human influence on recent climate. This scientific consensus is supported by over 99% of publishing climate scientists.[1]
Q2: How can we say climate change is real when it's been so cold in such-and-such a place?
A2: This is why it is termed "global warming", not "(such-and-such a place) warming". Even then, what rises is the average temperature over time – that is, the temperature will fluctuate up and down within the overall rising trend. To give an idea of the relevant time scales, the standard averaging period specified by the World Meteorological Organisation (WMO) is 30 years. Accordingly, the WMO defines climate change as "a statistically significant variation in either the mean state of the climate or in its variability, persisting for an extended period (typically decades or longer)."[2] Q3: Can't the increase of CO2 be from natural sources, like volcanoes or the oceans?
A3: While these claims are popular among global warming skeptics,[3][4] including academically trained ones,[5][6] they are incorrect. This is known from any of several perspectives:
Q4: I think the article is missing some things, or has some things wrong. Can I change it?
A4: Yes. Keep in mind that your points need to be based on documented evidence from the peer-reviewed literature, or other information that meets standards of verifiability, reliability, and no original research. If you do not have such evidence, more experienced editors may be able to help you find it (or confirm that such evidence does not exist). You are welcome to make such queries on the article's talk page but please keep in mind that the talk page is for discussing improvements to the article, not discussing the topic. There are many forums that welcome general discussions of global warming, but the article talk page is not such a forum. Q5: Why haven't the graphs been updated?
A5: Two reasons:
Q6: Isn't climate change "just a theory"?
A6: People who say this are abusing the word "theory" by conflating its common meaning with its scientific meaning.
In common usage, "theory" can mean a hunch or guess, but a scientific theory, roughly speaking, means a coherent set of explanations that is compatible with observations and that allows predictions to be made. That the temperature is rising is an observation. An explanation for this (also known as a hypothesis) is that the warming is primarily driven by greenhouse gases (such as CO2 and methane) released into the atmosphere by human activity. Scientific models have been built that predict the rise in temperature and these predictions have matched observations. When scientists gain confidence in a hypothesis because it matches observation and has survived intense scrutiny, the hypothesis may be called a "theory". Strictly speaking, scientific theories are never proven, but the degree of confidence in a theory can be discussed. The scientific models now suggest that it is "extremely likely" (>95%) to "virtually certain" (>99%) that the increases in temperature have been caused by human activity as discussed in the IPCC Fifth Assessment Report. Global warming via greenhouse gases by human activity is a theory (in the scientific sense), but it is most definitely not just a hunch or guess. Q7: Does methane cause more warming than CO2?
A7: It's true that methane is more potent molecule for molecule. But there's far less of it in the atmosphere, so the total effect is smaller. The atmospheric lifetime of methane (about 10 years) is a lot shorter than that of CO2 (hundreds to thousands of years), so when methane emissions are reduced the concentration in the atmosphere soon falls, whereas CO2 accumulates in the atmosphere over long periods. For details see the greenhouse gas and global warming potential articles.
Q8: How can you say there's a consensus when lists of "skeptical scientists" have been compiled?
A8: Consensus is not the same as unanimity, the latter of which is impractical for large groups. Over 99% of publishing climate scientists agree on anthropogenic climate change.[1] This is an extremely high percentage well past any reasonable threshold for consensus. Any list of "skeptical scientists" would be dwarfed by a comparably compiled list of scientists accepting anthropogenic climate change. Q9: Did climate change end in 1998?
A9: One of the strongest El Niño events in the instrumental record occurred during late 1997 through 1998, causing a spike in global temperature for 1998. Through the mid-late 2000s this abnormally warm year could be chosen as the starting point for comparisons with later years in order to produce a cooling trend; choosing any other year in the 20th century produced a warming trend. This no longer holds since the mean global temperatures in 2005, 2010, 2014, 2015 and 2016 have all been warmer than 1998.[12]
More importantly, scientists do not define a "trend" by looking at the difference between two given years. Instead they use methods such as linear regression that take into account all the values in a series of data. The World Meteorological Organisation specifies 30 years as the standard averaging period for climate statistics so that year-to-year fluctuations are averaged out;[2] thus, 10 years isn't long enough to detect a climate trend. Q10: Wasn't Greenland much warmer during the period of Norse settlement?
A10: Some people assume this because of the island's name. In fact the Saga of Erik the Red tells us Erik named the new colony Greenland because "men will desire much the more to go there if the land has a good name."[13] Advertising hype was alive and well in 985 AD.
While much of Greenland was and remains under a large ice sheet, the areas of Greenland that were settled by the Norse were coastal areas with fjords that, to this day, remain quite green. You can see the following images for reference:
Q11: Are the IPCC reports prepared by biased UN scientists?
A11: The IPCC reports are not produced by "UN scientists". The IPCC does not employ the scientists who generate the reports, and it has no control over them. The scientists are internationally recognized experts, most with a long history of successful research in the field. They are employed by various organizations including scientific research institutes, agencies like NASA and NOAA, and universities. They receive no extra pay for their participation in the IPCC process, which is considered a normal part of their academic duties. Q12: Hasn't global sea ice increased over the last 30 years?
A12: Measurements show that it has not.[14] Claims that global sea ice amounts have stayed the same or increased are a result of cherry picking two data points to compare, while ignoring the real (strongly statistically significant) downward trend in measurements of global sea ice amounts.
Arctic sea ice cover is declining strongly; Antarctic sea ice cover has had some much smaller increases, though it may or may not be thinning, and the Southern Ocean is warming. The net global ice-cover trend is clearly downwards. Q13: Weren't scientists telling us in the 1970s that the Earth was cooling instead of warming?
A13: They weren't – see the article on global cooling. An article in the Bulletin of the American Meteorological Society has reviewed the scientific literature at that time and found that even during the 1970s the prevailing scientific concern was over warming.[15] The common misperception that cooling was the main concern during the 1970s arose from a few studies that were sensationalized in the popular press, such as a short nine-paragraph article that appeared in Newsweek in 1975.[16] (Newsweek eventually apologized for having misrepresented the state of the science in the 1970s.)[17] The author of that article has repudiated the idea that it should be used to deny global warming.[18] Q14: Doesn't water vapour cause 98% of the greenhouse effect?
A14: Water vapour is indeed a major greenhouse gas, contributing about 36% to 70% (not 98%) of the total greenhouse effect. But water vapour has a very short atmospheric lifetime (about 10 days), compared with decades to centuries for greenhouse gases like CO2 or nitrous oxide. As a result it is very nearly in a dynamic equilibrium in the atmosphere, which globally maintains a nearly constant relative humidity. In simpler terms, any excess water vapour is removed by rainfall, and any deficit of water vapour is replenished by evaporation from the Earth's surface, which literally has oceans of water. Thus water vapour cannot act as a driver of climate change.
Rising temperatures caused by the long-lived greenhouse gases will however allow the atmosphere to hold more vapour. This will lead to an increase in the absolute amount of water vapour in the atmosphere. Since water vapour is itself a greenhouse gas, this is an example of a positive feedback. Thus, whereas water vapour is not a driver of climate change, it amplifies existing trends. Q15: Is the fact that other solar system bodies are warming evidence for a common cause (i.e. the sun)?
A15: While some solar system bodies show evidence of local or global climate change, there is no evidence for a common cause of warming.
Q16: Do scientists support climate change just to get more money?
A16: No,
Q17: Doesn't the climate vary even without human activity?
A17: It does, but the fact that natural variation occurs does not mean that human-induced change cannot also occur. Climate scientists have extensively studied natural causes of climate change (such as orbital changes, volcanism, and solar variation) and have ruled them out as an explanation for the current temperature increase. Human activity is the cause at the 95 to 99 percent confidence level (see the IPCC Fifth Assessment Report for details). The high level of certainty in this is important to keep in mind to spot mention of natural variation functioning as a distraction. Q18: Should we include the view that climate change will lead to planetary doom or catastrophe?
A18: This page is about the science of climate change. It doesn't talk about planetary doom or catastrophe. For a technical explanation, see catastrophic climate change, and for paleoclimatic examples see PETM and great dying. Q19: Is an increase in global temperature of, say, 3 degrees Celsius (5.4 degrees Fahrenheit) important?
A19: Though it may not sound like much, a global temperature rise of 3 degrees Celsius (5.4 degrees Fahrenheit) is huge in climate terms. For example, the sea level rise it would produce would flood coastal cities around the world, which include most large cities.
Q20: Why are certain proposals to change the article discarded, deleted, or ignored? Who is/was Scibaby?
A20: Scibaby is/was a long term abusive sock-master (or coordinated group of sock masters) who has created 1,027 confirmed sock puppets, another 167 suspected socks, and probably many untagged or unrecognized ones. This page lists some recent creations. His modus operandi has changed over time, but includes proposing reasonably worded additions on the talk page that only on close examination turn out to be irrelevant, misinterpreted, or give undue weight to certain aspects. Scibaby is banned, and Scibaby socks are blocked as soon as they are identified. Some editors silently revert his additions, per WP:DENY, while others still assume good faith even for likely socks and engage them. Q21: What about this really interesting recent peer-reviewed paper I read or read about, that says...?
A21: There are hundreds of peer-reviewed papers published every month in respected scientific journals such as Geophysical Research Letters, the Journal of Climate, and others. We can't include all of them, but the article does include references to individual papers where there is consensus that they best represent the state of the relevant science. This is in accordance with the "due weight" principle (WP:WEIGHT) of the Neutral point of view policy and the "Wikipedia is not an indiscriminate collection of information" principle (WP:IINFO) of the What Wikipedia is not policy. Q22: Why does the article define "climate change" as a recent phenomenon? Hasn't the planet warmed and cooled before?
A22: Yes, the planet has warmed and cooled before. However, the term "climate change" without further qualification is widely understood to refer to the recent episode and often explicitly connected with the greenhouse effect. Per WP:COMMONNAME, we use the term in this most common meaning. The article Climate variability and change deals with the more general concept. Q23: Did the CERN CLOUD experiment prove that climate change is caused not by human activity but by cosmic rays?
A23: No. For cosmic rays to be causing global warming, all of the following would have to be true, whereas only the italicized one was tested in the 2011 experiment:[28]
Q24: I read that something can't fix climate change. Is this true?
A24: Yes, this is true for all plausible single things including: "electric cars", "planting trees", "low-carbon technology", "renewable energy", "Australia", "capitalism", "the doom & gloom approach", "a Ph.D. in thermodynamics". Note that it is problematic to use the word "fix" regarding climate change, as returning the climate to its pre-industrial state currently appears to be feasible only over a timeframe of thousands of years. Current efforts are instead aimed at mitigating (meaning limiting) climate change. Mitigation is strived for through the combination of many different things. See Climate change mitigation for details. References
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Please review—submission under models section.
This submission was objected to based on "Has <the> model *really* 'the advantage of accurately demonstrating and predicting effects of the Global Warming phenomenon' ?????" Obviously it has demonstrated the effects of "Global Warming," based on high-school thermo', both global and regional, as for predicting? perhaps this IS stating too much. owever, back in 1985, no one, for example was relating the loss of polar ice to this phenomenon, I don't think I saw anything on the relation until 1995, that was predictive for the time. Since the purpose is to understand GW globally I can soften the statement. Thanks GESICC (talk) 06:25, 3 October 2010 (UTC)GESICC
All models are wrong, some models are useful. Please read...
A model for the phenomenon that yields intuitive results, and using only basic thermodynamics is to at first place the Earth and Sun in a state of thermal equilibrium. For initial understanding, no land masses are included in the model. The Earth can emit or absorb enough heat that it is warm at the equator and cool near the poles, which have ice caps. The total amount of ice remains constant, initially. The power of this model arises when we add a warming phenomenon that then sets the model out of equilibrium; burning wood, ethanol, fossil fuels†, radioactivity, more sunlight etc.. The first effect is not a dramatic increase in the Earth’s temperature (counter-intuitively), but a gradual reduction in the amount of ice near the poles. The glacial run-off, or heat absorbed by the ice melting (specific heat of ice) tends to keep the temperature of the Earth constant. Both of these phenomena have been observed: The non-drastic temperature change, contributing to controversy, is referenced throughout this article. While satellite models and geological surveys have demonstrated reduction in polar ice.[1] The model may be improved by the addition of land masses and geographic features. For example, the nearness of the glaciers in the Pacific Northwest caused a dramatic change in its climate during the 1990’s; unusually cold winters and snow. The continued retreat of the glaciers in recent years has caused a return to its former climate, as glacier water now warms before it reaches the Gulf of Alaska and the Pacific Coast. Another example is provided by the expansion of deserts-directly related to more water being driven from those regions by the increased heat and approach to a new equilibrium. Note that the model predicts non-dramatic temperature change due to Arctic Ice melting, when this ice is gone, new dynamics must replace it. Though simple, this model has the advantage of accurately demonstrating and predicting effects of the Global Warming phenomenon.
†= The burning of fossil fuels is the release of yesterday’s sunshine, effectively adding more sunlight or heat to the Earth.
GESICC (talk) 06:25, 3 October 2010 (UTC)GESICC
- The lack of conventions in your proposal makes it really hard to read. If it's a quote within a quote, please use an apostrophe (I read it as two quotes the first time through); spelling and complete sentences also help. You're talking about why these two edits were reverted.[1][2] I wasn't the one who reverted you (you should speak to Count Iblis and dave souza for their views), but I can already see several issues. For example, the explanation of thermodynamics reiterates paragraph one, this article is short on space under WP:SIZE, and defending why there needs to be a second explanation will have to be convincing. Nevertheless, if you were to submit this to a professional review, given your experience in a consulting firm, is this what a what a proposal should look like? If I were you, I would rewrite the proposal to explain what it adds to the article (putting the central points in a list helps by the way). -- CaC 155.99.230.104 (talk) 23:27, 3 October 2010 (UTC)
- Your edit engages in original research. You cite a source for the amount of water used to grow things, but it does not follow from that that "irrigation of deserts for farming has increased and redistributed water vapor" - this is merely what you believe happens. You additionally assert as fact that "farming in modern countries has created dead zones in the oceans," but provide no source. Please provide sources for all of your edits. Thanks. Hipocrite (talk) 18:47, 4 October 2010 (UTC)
Revision of 18:40, 4 October 2010 Addition of desert irrigation note
Mr. Souza's objection was that it lacked a reference; provided. Water vapor is a green house gas (qv). Desert farming contributes roughly 5 gallons per ounce of product (http://www.lacfb.org/commodity.pdf). QED, right?GESICC (talk) 18:56, 4 October 2010 (UTC)GESICC
- Your edit engages in original research. You cite a source for the amount of water used to grow things, but it does not follow from that that "irrigation of deserts for farming has increased and redistributed water vapor" - this is merely what you believe happens. You additionally assert as fact that "farming in modern countries has created dead zones in the oceans," but provide no source. Please provide sources for all of your edits. Thanks. Hipocrite (talk) 18:47, 4 October 2010 (UTC)
Hipocrite-You're mixing things up a bit. I do not see that if you move water to places it wasn't previously you are not redistributing it, I don't see how 'belief' enters the equation, it conservation of mass. “Dead zones” is referenced as another wiki-article, with sources, Oxygen dead zones are from the Carbon Dioxide cycle. GESICC (talk) 04:15, 7 October 2010 (UTC)GESICC
- Further, "qed" is not acceptable on wikipedia. Cite a source that says something - your belief it is obvious is not good enough. Hipocrite (talk) 18:58, 4 October 2010 (UTC)
QED-is just an expression. How about replace it with "is that good enough?" If not, it puzzles me what would be, Palmdale water department would report it if it wasn't true--I am not trying to establish water vapor is a GH gas, already done. Establishing it as a local Green House gas is pointless, farming takes 6-9 months minimum, etc..GESICC (talk) 04:15, 7 October 2010 (UTC)GESICC
- Let me add on the substance that the amount of water vapour in the atmosphere is not governed by evaporation alone, but by the balance of evaporation and precipitation. There is good evidence that relative humidity is fairly constant, i.e. the amount of water vapour in the atmosphere is controlled nearly exclusively by the air temperature. --Stephan Schulz (talk) 19:02, 4 October 2010 (UTC)
True, (p/P + p/P +...) = (n/N+n/N...) RT, however, if there is water where there usually isn't the n & p of water is > 0. Piping huge amounts of a green house gas to places that do not normally have it contributes to green house effects, I can't prove this-it’s both a definition and physics. Or as above, if you want me to site a reference for that particular area, well, I can understand that, almost, that's a classical argument, do different laws of physics need to be reproved under different circumstances? Sometimes other variables are involved, after all, but in this case, it is not reasonable to assume other extenuating circumstance, inconceivably large amounts of water are being put into arid environments all over the world. Let me counter-point and ask the gedunkin question; if the equivalent number of moles of CO2 were being released instaed of H2O would you still have the objection? Thanks all, if you still think something is amiss, I'll lock it down. GESICC (talk) 04:15, 7 October 2010 (UTC)GESICC
- The main difference is that atmospheric water has a lifetime of days, while the CO2 cycle operates on the order of centuries to millennia. We can measure that CO2 goes up, and we can measure that, globally, relative humidity very nearly remains constant. There may well be a minor effect, but saying that this is non-negligible is in no way obvious. We do need an explicit source for such a statement - see WP:OR. (And while "dunking" and water go well together, it's a Gedankenexperiment - no worries, I have an unfair advantage there ;-) --Stephan Schulz (talk) 06:38, 7 October 2010 (UTC)
- You're right, CO2's a LLGHG and the net change in water vapor is dependent on temperature (which is relatively constant). However, irrigation and deforestation changes the distribution of water vapor, which may lead to changes in hydrology flow patterns and cycles. I found a article in PNAS that discusses it, what do you guys think? -- CaC 155.99.230.68 (talk) 16:11, 7 October 2010 (UTC)
Stephan-I agree water has a lifetime of days-if we turned off the spigot today, the effects might be gone tomorrow, but until the spigot is turned off, there is a constant source, so half-life simply contributes to the equilibrium of the local environ. Global Humidity may be remaining constant, but we are interested in the local effects of very warm areas, (the heat, because of the humidity scale, may be depressing humidity readings-?). This is also true of CO2; life-time in the environment is not germane so long as there are sources keeping the reaction to the left. [Subject change] Although I can no longer find references, the oceans used to be able to suck up all the CO2 man could hope to produce, not so much anymore, which is why I added a link to Dead Zones (ecology). (It’s ironic we discuss the effect of CO2 production of fossil fuels, more than we discuss the direct contribution of heat from fossil fuels (talk about your short lifetimes, but nobody is turning off the spigot!) try digging up a credible reference for that! Enough fossil fuels get burned every day to melt 400+ cubic meters of water-from waste heat alone!)GESICC (talk) 20:38, 8 October 2010 (UTC)GESICC
- While relevent to our article on Climate change, land use and deforestation, I don't see how this article has much to do with Global warming. Hipocrite (talk) 16:22, 7 October 2010 (UTC)
CaC-Good bit of research, it is a short leap to evaporation from irrigation. Thanks.GESICC (talk) 20:38, 8 October 2010 (UTC)GESICC
- You know GESICC, if you've got no sources, you've got nothing on the table, and we're done. I'd hate to break it to you, your ideas are great, but Wikipedia is a tertiary resource and under WP:OR (which is policy), you aren't going to get anywhere. --CaC 155.99.230.93 (talk) 04:32, 9 October 2010 (UTC)
Residence time of CO2?
This article repeats the idea that CO2 residence time is of the order of a hundered years or so but other papers say this not so. See this paper and the supporting cites: "Potential Dependence of Global Warming on the Residence Time (RT) in the Atmosphere of Anthropogenically Sourced Carbon Dioxide" R.H. Essenhigh* Energy Fuels, 2009, 23 (5), pp 2773–2784. The statement of residence time therefore needs correction -right? MarkC (talk) 10:16, 14 October 2010 (UTC)
- No. The Essenhigh paper is badly confused, and its rendition in the blogosphere is worse. The residence time of a given CO2 molecule in the atmosphere is on the order of 4 years (since the total carbon exchange between atmosphere and other reservoirs is ~200 GT/year, and the atmosphere contains ~750GT). But that is not the same as the equilibrium time (how long after a CO2 pulse will it take to revert to normal). We have plenty of research on CO2 lifetimes. I'm sure Boris can point out about 5 publications from the top of his head, and explain this much better. But what is telling is that this paper is not published in any atmospheric science journal, but in one dedicated to fossil fuels... --Stephan Schulz (talk) 11:32, 14 October 2010 (UTC)
I'm sorry but that makes absolutely no sense. For perturbation of an equilibrium, the rate of return is the _sum_ of the forward and back rates. Since the CO2 record shows the seasonal variation the equilibrium time (1/e) cannot be ~100 years. To dismiss a paper and others it cited just because of the title of the Journal title is not scientific nor objective is it? On the other hand, an exponential never returns, so scientists don't characterize the return except in terms of the time const. or half time etc. Thus a 5 year time constant will reach 1- (1/e)^20 of its final value in one hundred years but what's the point of that figure, it's most misleading. Surely we could do with some better description of the assumptions that go into such an estimate or else say there's controversy? Cheers 125.237.187.133 (talk) 12:25, 17 October 2010 (UTC)
- One paper doesn't make a controversy. I suggest that the thing to do here is to read our articles carbon dioxide, carbon dioxide in Earth's atmosphere and carbon cycle and recommend any changes you think should be made to those articles. If you're successful in getting consensus for changes there then it might be time to update this article, in which our coverage should essentially reflect those articles in summary form. --TS 12:30, 17 October 2010 (UTC)
- Hi, it's not just one paper as the reference list in that paper makes clear. BUT even more importantly, the residence time has been measure by 14^C injection following nuclear tests and its not 100 years see: http://cdiac.esd.ornl.gov/trends/co2/well-gr.html. Such direct measurement surely outweighs all modeling studies? MarkC (talk) 12:41, 17 October 2010 (UTC)
- The answer is still the same. Take it to the other articles and get consensus that they're in error and need to be changed, then we can see if this one needs to be updated. --TS 12:43, 17 October 2010 (UTC)
- I had a look at the pages and I could not find a reference to the 100 years... Did I miss it?
- Let me try again. The atmosphere exchanges about 25% of its CO2 per year with much larger reservoirs (especially the oceans). Thus, the time a given CO2 molecule stays in the atmosphere is about 4 years. But the time for the excess CO2 to be removed from the atmosphere is much longer. It's like peeing into a pool. The pee will be diluted pretty soon, so the local concentration will sink very quickly. But the overall level of the pool will only be the same once the extra water has evaporated. --Stephan Schulz (talk) 13:34, 17 October 2010 (UTC)
- Thank you Stephan (although you analogy is worrying ;-P), the problem is not as you suggest. The idea that atmospheric CO2 will take more than ~100 years to appreciably decline after a perturbation is clearly wrong as direct measurements show a faster equilibration (as simple math shows it must be -given the seasonal variations). Perhaps you were unaware of these data? http://cdiac.esd.ornl.gov/trends/co2/well-gr.html This shows that the time course of return to steady state is 10x faster than suggested... Therefore if CO2 production were returned toward preindustrial levels tomorrow (say) the decline in atmospheric CO2 would be as fast as this graph shows -not >100 years. It's not the total C in the system that matters but the atmospheric component -right? MarkC (talk) 09:27, 18 October 2010 (UTC)
- To reiterate (I hope) the basic point, an individual carbon dioxide molecule has an expected lifetime in the atmosphere of 3-4 years; after that it's dissolved in the oceans or by plant respiration or whatever. At the same time biota, various human industrial and agricultural activities and the oceans release carbon dioxide into the atmosphere. However there is a net imbalance in carbon dioxide inputs and outputs in the atmosphere, and this excess in the atmosphere eventually finds its way into the oceans. The distinction you seem to be failing to draw is that between the 3-4 year residency period and that much longer time for the excess carbon dioxide to find its way (primarily) into the oceans. The IP's basic error above seems to have been in this statement: " Since the CO2 record shows the seasonal variation the equilibrium time (1/e) cannot be ~100 years." That's nonsense. It's like saying that since I can stand at the shore and see the waves periodically advancing and receding over a scale of seconds, it's impossible that the tide could take hours to go out. --TS 11:21, 18 October 2010 (UTC)
- Hi TC. Let's try to agree on something: It's not the total C in the system that matters but the atmospheric component -right? If you agree, then its not the time taken for all the C sinks to equilibrate that matter but only the atmospheric component and that, as I have shown and we seem to agree is more like 4-7 years. Thus if CO2 production were stopped tomorrow CO2 will fall with that half time, not 100 years. Do you not agree? 125.237.187.133 (talk) 09:06, 19 October 2010 (UTC)
- I don't see a TC here so I'll assume you meant TS. I still don't see how you get from residence time to equilibrium. You seem to be saying they're identical. --TS 09:33, 19 October 2010 (UTC)
- No, I am not saying they are identical. The key is the time taken for atmospheric CO2 to fall toward steady state values after a perturbation. It is only the CO2 in the atmosphere that is relevant for warming, not the amount/redistribution in other sinks. This approaches steady state in << 100 years as the 14C data shows -do you agree? 125.237.187.133 (talk) 09:48, 20 October 2010 (UTC)
- No, it does not. See above. The C14 gets diluted very quickly due to the large carbon flow, but the amount of carbon in the atmosphere drops a lot slower. --Stephan Schulz (talk) 10:05, 20 October 2010 (UTC)
- Hi, it's not just one paper as the reference list in that paper makes clear. BUT even more importantly, the residence time has been measure by 14^C injection following nuclear tests and its not 100 years see: http://cdiac.esd.ornl.gov/trends/co2/well-gr.html. Such direct measurement surely outweighs all modeling studies? MarkC (talk) 12:41, 17 October 2010 (UTC)
NASA image: The World Revs its Heat Engine
NASA's image at Flickr, which is provided with an explanatory caption, might well be edited into this text. "Recently, NASA researchers discovered that incoming solar radiation and outgoing thermal radiation increased in the tropics from the 1980s to the 1990s." The NASA image, dated 2001, might be correlated with contemporary Bush administration public observations about global warming.--Wetman (talk) 14:41, 14 October 2010 (UTC)
The objectivity and accuracy of this page needs advancement.
In reviewing this page, it is clear that only one POV is given. The only mention of serious concerns with the science of Global Warming is in a dismissive and marginalizing way. No mention of the comical errors and practices of the IPCC and it's methods is made. That needs to be presented early and honestly.
This is sad.
Is there anyone there to save Wikiperdia from the marginalization that will happen from this lack of balanced presentation?
If the goal is to be a reliable and authoritative resourse of information, than self interest, political bias, imbalanced and untrue information must be prevented or at least balanced with a complementary and thorough opposition POV.
Please begin to rebalance or clean this lop-sided article today.
If not, Wikipedia will not only continue to lose credibility but will become a joke to all but the most imbalanced and lop-sided researchers and a competitor will fill the gap and draw those who want truth and objectivity away.
Thanks-
SeanDeepsean666 (talk) 02:11, 19 October 2010 (UTC)
- Per WP:V, we need reliable sources to include that kind of content, according to its weight. Jesstalk|edits 02:29, 19 October 2010 (UTC)
- Wikipedia relies on science published in refereed journals. The "fair and balanced" coverage you would like to see would give equal weight to published papers and to Fox News, but that is not Wikipedia policy. Rick Norwood (talk) 13:40, 19 October 2010 (UTC)
Wentz 2007: How Much More Rain Will Global Warming Bring?
I've removed this reference to a single paper for now. It was added today by Africangenesis. How well accepted is Wentz? Has it been replicated? Does the paper support the statement in which it is cited? --TS 12:00, 19 October 2010 (UTC)
- The paper proper does mention the discrepancy, but with a few caveats. It does not mention the possible reduction in droughts. --Stephan Schulz (talk) 12:14, 19 October 2010 (UTC)
- Well that's what I'm getting at. It sounds like a reasonable conjecture but I'd like to see if the point about the effect on drought predictions has been made by people who (unlike me) know what they're talking about.
- Would I be right to assume that this paper was accepted for publication too late to make the IPCC AR4 of 2007? --TS 12:22, 19 October 2010 (UTC)
- Yes, model results are often published before diagnostic literature based upon those results is produced to put the results in perspective. The reduction in drought fears is from the comment by the editors of Science which is also cited, but it is an obvious implication.--Africangenesis (talk) 12:27, 19 October 2010 (UTC)
- Would I be right to assume that this paper was accepted for publication too late to make the IPCC AR4 of 2007? --TS 12:22, 19 October 2010 (UTC)
Since when is peer review pubs, cited by other literature and not contradicted in 3 years insufficient?
Tony, please recall our discussion at [3]. My references meet the standards. The clique that had controlled this article drove me and many other good editors away. I read at wattsupwiththat that this problem might have been rectified. I hope you aren't continuing the problem. --Africangenesis (talk) 12:24, 19 October 2010 (UTC)
- I've asked some questions above that I think we should address. I don't think you should rely on blogs for scientific matters. --TS 12:32, 19 October 2010 (UTC)
- My 'yes" was in reference to your question about whether it was too late for the IPCC FAR. I don't know that they were even trying to make the FAR. BTW, the immediately previous sentence about the models getting the Arctic ice cap melt wrong (Scambos says the models are 30 years behind) didn't make the FAR either. However, even if it had made the FAR I doubt it would have made any difference. None of the projections were adjusted for errors reported in diagnostic literature that were in time to make the FAR. Recall that I was the one that forced the cadre to admit that only CO2 scenarios and models of different sensitivities contributed to the IPCC ranges. They had been trying to claim that model uncertainty was also included, it wasn't. --Africangenesis (talk) 12:43, 19 October 2010 (UTC)
- The clique that had controlled this article... - please leave that attitude out of editing this or any other article. In the context of these articles, the arbitration committee has affirmed that behaviour like that is unacceptable. You would do much better to focus more on the article and less on personalities. Guettarda (talk) 13:01, 19 October 2010 (UTC)
I like Stephan Schulz's parsimonious summary of the paper, which is on the article now.[4] --TS 12:38, 19 October 2010 (UTC)
- I'm accepting it with the "may have" removed. There is no reason to single out satellite observations of precipitation for a "may have". There are many other places just as deserving of a may have, and model projections and claims of risks and possible effects are far less certain.--Africangenesis (talk) 12:55, 19 October 2010 (UTC)
- The "may have" reflects the caveats in the paper itself: "The reason for the discrepancy between the observational data and the GCMs is not clear. One possible explanation is that two decades is too short of a time period, and thus we see internal climate variability that masks the limiting effects of radiative forcing. [...] Another possible explanation is that there are errors in the satellite retrievals, but the consistency among the independent retrievals and validation of the winds with other data sets suggests otherwise. Lastly, there is the possibility that the climate models have in common a compensating error in characterizing the radiative balance for the troposphere and Earth's surface." --Stephan Schulz (talk) 13:03, 19 October 2010 (UTC)
- I think we should go with the "may have." Africangenesis, do you accept that the paper is cautious on this topic? --TS 13:09, 19 October 2010 (UTC)
- No, I think they are only admitting a theoretical possibility which they think is unlikely due to other evidence. Frankly, they are seriously questioning the models credibility, the model behavior doesn't make sense to them while their satellite results do:
- "The difference between a subdued increase in rainfall and a C-C increase has enormous impact, with respect to the consequences of global warming. Can the total water in the atmosphere increase by 15% with CO2 doubling but precipitation only increase by 4% (1)?Will warming really bring a decrease in global winds? The observations reported here suggest otherwise, but clearly these questions are far from being settled."
- Under representing the negative feedback of the water cycle response to warming adds to the evidence that seriously calls into question the high model sensitivities.--Africangenesis (talk) 13:44, 19 October 2010 (UTC)
- You're surely underplaying the uncertainty of their reasoning, which they profess quite fully. For instance they say "One possible explanation is that two decades is too short of a time period, and thus we see internal climate variability that masks the limiting effects of radiative forcing." This is why I think the word "may" should go back. --TS 13:49, 19 October 2010 (UTC)
- That particular two decade caveat is not about the discrepancy in the precipitation observations and model results being incorrect. It is suggesting a way that both may be right, because the observations may be an anomaly due to just being a short observation of one instance of the climate. Whereas it is possible that the models have the physics right and just aren't simulating this particularly instance of the climate that has high precipitation and increased winds. It is anticipating a common apologia for model differences with observations, that the models can't have all the initial state given the unknowns so may be statistically correct in the long run despite not being able to reproduce a specific observed climate instantiation. The authors are granting that possibility, which is very generous of them since model skill has not been validated. --Africangenesis (talk) 14:02, 19 October 2010 (UTC)
- You're surely underplaying the uncertainty of their reasoning, which they profess quite fully. For instance they say "One possible explanation is that two decades is too short of a time period, and thus we see internal climate variability that masks the limiting effects of radiative forcing." This is why I think the word "may" should go back. --TS 13:49, 19 October 2010 (UTC)
- No, I think they are only admitting a theoretical possibility which they think is unlikely due to other evidence. Frankly, they are seriously questioning the models credibility, the model behavior doesn't make sense to them while their satellite results do:
- I think we should go with the "may have." Africangenesis, do you accept that the paper is cautious on this topic? --TS 13:09, 19 October 2010 (UTC)
- The "may have" reflects the caveats in the paper itself: "The reason for the discrepancy between the observational data and the GCMs is not clear. One possible explanation is that two decades is too short of a time period, and thus we see internal climate variability that masks the limiting effects of radiative forcing. [...] Another possible explanation is that there are errors in the satellite retrievals, but the consistency among the independent retrievals and validation of the winds with other data sets suggests otherwise. Lastly, there is the possibility that the climate models have in common a compensating error in characterizing the radiative balance for the troposphere and Earth's surface." --Stephan Schulz (talk) 13:03, 19 October 2010 (UTC)
- I'm accepting it with the "may have" removed. There is no reason to single out satellite observations of precipitation for a "may have". There are many other places just as deserving of a may have, and model projections and claims of risks and possible effects are far less certain.--Africangenesis (talk) 12:55, 19 October 2010 (UTC)
FYI, other scientists are concerned about the implications of the Wentz results for the models. EOS stands for Earth Observations Systems, and is a weekly publication of the AGU. Articles probably have about the level of peer review as a conference paper. Lambert of the Hadley Center and Stine, Krakauer and Chiang of UC Berkely write: "Thus if GCMs do underestimate global precipitation changes, the simulation of other climate variables will be effected." Eos Vol 28 No. 21
In the same issue of Eos, Previdi and Liepert explain: "This non-radiative energy transfer takes primarily the form of latent and sensible heat fluxes with the latent heat flux being about 5 times larger than the sensible heat flux in the global mean. The latent heat flux from the surface to the troposphere is associated mainly with the evaporation of surface water. When this water condenses in the troposphere to form clouds and eventually precipitation, the troposphere heats up and then radiates this energy gain out to space. The radiative energy loss from the troposhere is equal to the energy heat gain at the surface. The global water cycle is therefore fundamentally a part of the global energy cycle and any changes in global mean precipitation and evaporation are consequently constrained by the energy budgets of the troposhere and surface."`--Africangenesis (talk) 14:12, 19 October 2010 (UTC)
- Granted all the above, it still does not explain your removal of the word "may" which, Stephan correctly says, reflects the caveats in the paper. None of the sources you cite, it seems to me, justify that removal. Tasty monster (=TS ) 15:10, 19 October 2010 (UTC)
- Shouldn't there at least be some evidence that gives one pause about the satellite observations? The author doesn't acknowledge any, just that there is an unexplained discrepency between the observations and the models. The independent evidence the author discusses is consistent with his observations and inconsistent with the models. Mistakes in most any scientific work may hypothetically be found in the future. I doubt you would want to consistently apply a threshold this low, because you will end up having to qualify nearly everything.--Africangenesis (talk) 16:02, 19 October 2010 (UTC)
- Granted all the above, it still does not explain your removal of the word "may" which, Stephan correctly says, reflects the caveats in the paper. None of the sources you cite, it seems to me, justify that removal. Tasty monster (=TS ) 15:10, 19 October 2010 (UTC)
I'm only suggesting that we put back the qualification "may" into a reference to a single fairly recent and as yet unreplicated paper. In this decision I take into account the authors' own caveats which you yourself have clearly read, acknowledge and have understood. I don't think that is unreasonable. If you think similar qualifications should apply elsewhere in the article, make your case. Tasty monster (=TS ) 18:01, 19 October 2010 (UTC)
- Just so you understand what we're talking about, by the way, I suggest you comb through this article, and find all the references to singleton research papers. From my own recollection of doing a similar search a couple of months ago, I don't think you'll find many such references, let alone to papers so recently published. Tasty monster (=TS ) 18:18, 19 October 2010 (UTC)
- You appear to be assuming that the Wentz paper occurred in isolation. It is more a culmination of discrepancies in model representations of lapse rates and wind fields. So the Hadley cell paper mentioned above it in the article and the papers the Wentz paper references are essentially other facets of the same issues. The model issuess with tropical radiative imbalance shown in separate papers by Lindzen and Spencer form part of the pattern. The model diagnostic literature is mutually reinforcing, as the EOS discussion I mentioned above indicates "the simulation of other variables will be effected". The models are sprouting with other variables that they get wrong, and the precipitation, lapse rate and readiative imbalances issues remain.--Africangenesis (talk) 23:39, 19 October 2010 (UTC)
- If what you say is verifiable we ought to be able to write about it all from reliable sources. And if the pattern is well established enough to write about in an encyclopedia there really ought to be a few decent review papers around to consolidate it all. So let's have it, let's stop pussyfooting with individual research papers, let's have the real deal. --TS 23:36, 19 October 2010 (UTC)
- So that is the tactic. Undisputed 3 year old results published in the journal Science that make sense of body of previous work don't count until a review article without new results discusses them. Did you apply that standard to the Lu Jian hadley cell paper from which the expansion of deserts statements is derived? Did you notice that the NAS climate summary is not peer reviewed and doesn't have references for the statement is the source of CO2 as the "cause" of most of the recent warming? Is the Stroeve paper on the Arctic melting issues with the models discussed by a review paper?--Africangenesis (talk) 23:53, 19 October 2010 (UTC)
- If what you say is verifiable we ought to be able to write about it all from reliable sources. And if the pattern is well established enough to write about in an encyclopedia there really ought to be a few decent review papers around to consolidate it all. So let's have it, let's stop pussyfooting with individual research papers, let's have the real deal. --TS 23:36, 19 October 2010 (UTC)
- You appear to be assuming that the Wentz paper occurred in isolation. It is more a culmination of discrepancies in model representations of lapse rates and wind fields. So the Hadley cell paper mentioned above it in the article and the papers the Wentz paper references are essentially other facets of the same issues. The model issuess with tropical radiative imbalance shown in separate papers by Lindzen and Spencer form part of the pattern. The model diagnostic literature is mutually reinforcing, as the EOS discussion I mentioned above indicates "the simulation of other variables will be effected". The models are sprouting with other variables that they get wrong, and the precipitation, lapse rate and readiative imbalances issues remain.--Africangenesis (talk) 23:39, 19 October 2010 (UTC)
I think you're giving me good critiques of the article as it stands at present, but I don't think you're convincing me that we should write about something because you say it is so. --TS 23:57, 19 October 2010 (UTC)
- So convincing you is the standard. WP:OWN.--Africangenesis (talk) 00:05, 20 October 2010 (UTC)
- It is not the standard. Tony is simply the one who has done the tedious work of engaging you and working out what exactly you want, as well as some of the best arguments for and against that. You need to convince enough editors here to get a consensus. Tony has just signalled to you that you are not convincing him. But maybe you can convince someone else. Editors can now look at this section, and if they think that the current outcome (no change, per WP:BURDEN) is not the right one, they can put in their weight. Otherwise most will stay silent because it's more convenient when Tony does all the work. Hans Adler 00:19, 20 October 2010 (UTC)
- Agree with Hans Adler, although I believe it's more about m:Conflicting Wikipedia philosophies than WP:BURDEN; newer/shorter articles tend to be more inclusionistic while older/longer articles more exclusionistic. Tony is being critical of what ought to be included, and in my opinion it's justified under WP:SPINOFF (while you may disagree). Of course we may debate whether WP:SPINOFF or Tony's standards applies, or we may debate how to improve the encyclopedia. As you've pointed out the flaws in Tony's standards, you've also provided great critiques for the article. Why don't you run with that? Secondly, no one has told you that Wenz 2007 has to be in this article; remember that the section "Climate model" is a summery section of climate models, and in that context I find Wenz 2007 little more notable than the one that says increasing the resolution of older models creates non-neglegible changes in the distribution of precipitation. --CaC 155.99.230.89 (talk) 03:34, 20 October 2010 (UTC)
- It is a little more notable that the models fail to reproduce the increase in precipitation in the climate, than that increasing the resolution of the models doesn't fix their precipitation problems.--Africangenesis (talk) 04:38, 20 October 2010 (UTC)
- Agree with Hans Adler, although I believe it's more about m:Conflicting Wikipedia philosophies than WP:BURDEN; newer/shorter articles tend to be more inclusionistic while older/longer articles more exclusionistic. Tony is being critical of what ought to be included, and in my opinion it's justified under WP:SPINOFF (while you may disagree). Of course we may debate whether WP:SPINOFF or Tony's standards applies, or we may debate how to improve the encyclopedia. As you've pointed out the flaws in Tony's standards, you've also provided great critiques for the article. Why don't you run with that? Secondly, no one has told you that Wenz 2007 has to be in this article; remember that the section "Climate model" is a summery section of climate models, and in that context I find Wenz 2007 little more notable than the one that says increasing the resolution of older models creates non-neglegible changes in the distribution of precipitation. --CaC 155.99.230.89 (talk) 03:34, 20 October 2010 (UTC)
- It is not the standard. Tony is simply the one who has done the tedious work of engaging you and working out what exactly you want, as well as some of the best arguments for and against that. You need to convince enough editors here to get a consensus. Tony has just signalled to you that you are not convincing him. But maybe you can convince someone else. Editors can now look at this section, and if they think that the current outcome (no change, per WP:BURDEN) is not the right one, they can put in their weight. Otherwise most will stay silent because it's more convenient when Tony does all the work. Hans Adler 00:19, 20 October 2010 (UTC)
I made two edits yesterday on this article, my first edits on global warming since March, so I don't think I'm in danger of credibly being accused of exercising ownership.
I'm still in favor of restoring Stephan's "may have" qualification to the description of the singleton research paper which is the subject of this section. Africangenesis is raising interesting ideas, and I think we should write them up if they can be adequately sourced. First, though, if the relevant articles on climate modeling are out of date, we should improve them, then update this one to reflect their new content. --TS 09:16, 20 October 2010 (UTC)
- In the past, wasn't ownership of this more prominent article partially maintained by insisting that details relevant to disputes and credibility of the scientific claims on this page, be pushed off to other specialized, less prominent pages, i.e., isn't disputing edits on this page on such a basis, "battleground behavior"? --Africangenesis (talk) 10:14, 20 October 2010 (UTC)
Climate models
- See the following articles:
- They both need improvement. --TS 22:10, 19 October 2010 (UTC)
I would suggest that the section regarding climate models needs some review at this point. In its current state, it avoids issues that are core to the underlying problematic. I will discuss a few points, but feel free to comment or add other ideas.
"The main tools for projecting future climate changes are mathematical models (...). Although they attempt to include as many processes as possible, simplifications of the actual climate system are inevitable because of the constraints of available computer power and limitations in knowledge of the climate system."
- Simplifications of the climate system in the models are inevitable first and foremost because there exists no mathematical equations for a cloud or for other physical processes. This issue is obscured by the current text.
- The issue of available computer power is irrelevant and should be removed. There are no scientific grounds to support that future computers will allow the development of climate models that do not need simplifications. Computer limitations in climate studies can be more correctly attributed to complexity issues rather than to a lack of power.
- Actually, there used to be a mention of the inherent complexity of the underlying system as a cause for the need for simplifications, in lieu of "limitations in knowledge". I think the former was more accurate by far and should be re-introduced. Climate-related sciences cannot escape the fact that the object of their studies, i.e. the climate, is a complex system in the scientific sense, which has enormous implications with regard to modelling. Complexity science acknowledges it. See [5] for a quick summary.
"The physical realism of models is tested by examining their ability to simulate current or past climates. Current climate models produce a good match to observations of global temperature changes over the last century, but do not simulate all aspects of climate."
- As stated these sentences are true but also obscure core issues, most importantly the fact that the ability to reproduce the past is not related to the ability to predict the future.
--Childhood's End (talk) 19:04, 19 October 2010 (UTC)
- These are interesting ideas, but what do you suggest? Are we to write our own critique of climate modeling as seen through the lens of the complexity theorist? Tasty monster (=TS ) 19:19, 19 October 2010 (UTC)
- Also note that these models don't attempt to predict the future, and David Orrell seems to be the author of a generalist popular book who apparently misunderstands some aspects of climate science. . . dave souza, talk 19:54, 19 October 2010 (UTC)
- And you are of course here to tell when a PhD in maths with several pusblished articles misunderstands mathematical issues. Please also remind BLP, as it applies to talk pages. --Childhood's End (talk) 20:28, 19 October 2010 (UTC)
- A matter of history. It doesn't need advanced maths to undestand that the Intergovernmental Panel on Climate Change (IPCC) wasn't founded to refine the result using advanced mathematical models. And projections ain't predictions. . . . dave souza, talk 20:44, 19 October 2010 (UTC)
- And you are of course here to tell when a PhD in maths with several pusblished articles misunderstands mathematical issues. Please also remind BLP, as it applies to talk pages. --Childhood's End (talk) 20:28, 19 October 2010 (UTC)
- If these ideas are as fundamental and systemic as seem to be suggested here, how come only one PhD author has noticed them, and then published his findings as one FAQ among many on an internal page of his website? What about all the other thousands of climate scientists, the university departments, the peer-review process, the IPCC? Did none of them think to look into this, even after he blew the whole field of study apart by publishing this FAQ? It seems unlikely to me that there is such large conspiracy of silence in the mainstream literature. --Nigelj (talk) 19:59, 19 October 2010 (UTC)
- I gave this source as an example, please re-read my post. It is your interpretation that there might be a conspiracy. My view is that since this is an advanced mathematical issue and that climate scientists are not pure mathematicians, they are thus unqualified to fully grasp the limitations of mathematical climate models. But the fact that climate scientists do not grasp it, and thus do not discuss it, does not mean that mathematics should be ignored when it comes to mathematical models. If global warming/climate change topics must address mathematical climate models, they have to address it wholly and not cherry-pick. --Childhood's End (talk) 20:28, 19 October 2010 (UTC)
- Also note that these models don't attempt to predict the future, and David Orrell seems to be the author of a generalist popular book who apparently misunderstands some aspects of climate science. . . dave souza, talk 19:54, 19 October 2010 (UTC)
- The issue isn't complexity, rather chaotic behavior. The climate is not chaotic, at least not on the time scales one is interested in when studying global warming. Then the problems do actually boil down to lack of computing power, or lack of mathematical techniques to settle certain problems. With enough computing power you could e.g., simulate cloud formation from first principles, because the fundamental physics underlying this is known (we know the properties of water molecules and how they interact with each other).
- In theoretical physics, one can sometimes use mathematical tricks to circumvent such problems. A typical method is to extend the exact mathematical model describing the phenomena one is interested in, by multiplying terms that are responsible for intractible complex phenomena by some parameter g. You then attempt to develop perturbation theory around g = 0 to find the behavior at g = 1. Typically, what you find is that the perturbation series does not converge (which often has its very physical origin in the complex phenomena that are absent at g = 0). But usually, the perturbation theory does contain enough information to reconstruct the function using resummation techniques, allowing you to to compute the behavior at g = 1. Count Iblis (talk) 20:37, 19 October 2010 (UTC)
- With all due respect, I disagree with your premise. This is a complexity issue, not a mere chaos issue. Indeed if the climate is not chaotic, as you point out, it remains a complex adaptive system with its inherent modelling difficulties. Chaos does not pose the same problems as complexity when it comes to modelling future events. Also, no matter the time frame, each model must have initial conditions relying on approximations, measurements and parametrization and thus involging error which evolves with time differently than it would if it was just chaos and the famous butterfly effect. See Conway's game of life or computational complexity theory for a gross picture of what I am trying to point out. --Childhood's End (talk) 21:22, 19 October 2010 (UTC)
- This isn't the place to discuss these fine points. Whatever bearing they actually have on climate science will have been well discussed in the relevant published literature. I suggest you have a look at TS's suggestion below, and try making a contribution to one or more of the detailed articles on these matters. But I suggest you have good references ready, not only for WP:V, but also for whatever discussion you may find on that talk pages of these specialist articles. --Nigelj (talk) 21:29, 19 October 2010 (UTC)
- With all due respect, I disagree with your premise. This is a complexity issue, not a mere chaos issue. Indeed if the climate is not chaotic, as you point out, it remains a complex adaptive system with its inherent modelling difficulties. Chaos does not pose the same problems as complexity when it comes to modelling future events. Also, no matter the time frame, each model must have initial conditions relying on approximations, measurements and parametrization and thus involging error which evolves with time differently than it would if it was just chaos and the famous butterfly effect. See Conway's game of life or computational complexity theory for a gross picture of what I am trying to point out. --Childhood's End (talk) 21:22, 19 October 2010 (UTC)
- In theoretical physics, one can sometimes use mathematical tricks to circumvent such problems. A typical method is to extend the exact mathematical model describing the phenomena one is interested in, by multiplying terms that are responsible for intractible complex phenomena by some parameter g. You then attempt to develop perturbation theory around g = 0 to find the behavior at g = 1. Typically, what you find is that the perturbation series does not converge (which often has its very physical origin in the complex phenomena that are absent at g = 0). But usually, the perturbation theory does contain enough information to reconstruct the function using resummation techniques, allowing you to to compute the behavior at g = 1. Count Iblis (talk) 20:37, 19 October 2010 (UTC)
This is going to go the way of most discussions on verifiability, synthesis and the like. While I was out I browsed one or two articles on climate modeling using my tiny and not very powerful telephone. It looked to me as if those articles needed renovation. I would like to suggest that those who want to improve our coverage of climate models could do a lot worse than turn those from indifferent to middling articles into spectacularly good ones. Then we could summarise those articles in the section on modeling in this article. -TS 20:36, 19 October 2010 (UTC)
- Good call. . . dave souza, talk 20:48, 19 October 2010 (UTC)
- Looks like a good idea to me too. --Childhood's End (talk) 21:24, 19 October 2010 (UTC)
Discovery of a critique suitable for WP of the accuracy of modeling of climate and of its extrapolation into the future, and of the value of more powerful computers in that effort is improbable. All one can accomplish is a general word of caution that isn't useful, especially if it is to buttress a general skepticism that amounts to suggesting that our best efforts to sort things out are so bad that we should abandon them and work from gut instincts alone. Brews ohare (talk) 21:27, 19 October 2010 (UTC)
I've taken the liberty of adding a hatnote to this section pointing to two articles on this subject that could benefit from expert improvement. --TS 22:12, 19 October 2010 (UTC)
- It would seem that most of the concerns raised here are dealt with in the following parts of Global climate models, or related articles:
- "No model – whether a wind tunnel model for designing aircraft, or a climate model for projecting global warming – perfectly reproduces the system being modeled. Such inherently imperfect models may nevertheless produce useful results. In this context, GCMs are capable of reproducing the general features of the observed global temperature over the past century"
- "Coupled climate models do not simulate with reasonable accuracy clouds and some related hydrological processes (in particular those involving upper tropospheric humidity). Problems in the simulation of clouds and upper tropospheric humidity, remain worrisome because the associated processes account for most of the uncertainty in climate model simulations of anthropogenic change."
- the article Parametrization (climate)
- the article Climate change feedback and its sub-articles
- If we want to insert the word "complex" into the first quote "reproduces the complex system" and link it to complexity theory, that might be an improvement. Overall, however, there's no reason to assume that the complexity-induced error (differences between model and future reality) are greater than the researchable, and modellable non-linear effects described in Climate change feedback. And ultimately this concern is about just such errors, to the extent it isn't an argument for us to throw up our hands vis a vis modeling complex systems.--Carwil (talk) 23:10, 19 October 2010 (UTC)
URL not pointless.
Note to NuclearWarfare re your recent minor edit: the url is not pointless, even with a doi. It is an alternate way of getting there. Sometimes we have only one or the other, but having both is not to be despised. - J. Johnson (JJ) (talk) 22:55, 19 October 2010 (UTC)
Ocean acidification, prediction vs projection
Stephan, Are you quite sure that "any chemist can predict the continued ocean acidification." in light of the fact that CO2 has reduced soluability in the oceans as temperatures rise, and in light of the fact that there is still some uncertainty regarding sources and sinks of CO2? There is a reason these things are modeled and not just assumed. --Africangenesis (talk) 10:06, 20 October 2010 (UTC)
- ^ Copious references, eg. "Patterns of glacier response to disintegration of the Larsen B ice shelf, Antarctic Peninsula," Christina L. Hulbea, Ted A. Scambosb, Tim Youngbergc and Amie K. Lambd, Global and Planetary Change, Volume 63, Issue 1, August 2008, Pages 1-8
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