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Post by radiant on Aug 18, 2009 13:58:47 GMT
You dont want to measure tiny changes?It's not a case of not wanting to measure them it's a case of knowing and managing them. The micro-climate temperature effects are well understood. The Armagh Observatory will be well aware of the implications of measurement location. The point is there will always be measurement error. The important thing is not necessarily to remove the error but to recognise it and to understand how sensitive it is with respect to your overall result. Why are you looking at a tiny time period of 30 years and giving it meaning?Three reasons: 1. A 30 year period is, in a statistical sense, long enough to smooth out most (but not all) of the natural fluctuations. Note that you can pick out a number of short term periods in the last 30 years which show a negative trend because of short term fluctuations, but when you get to 20 or 30 years the trends become less sensitive (that word again) to short term blips. 2. The satellite era began ~30 years ago, so we have more independent sources. The data has also been more closly analysed over the past 30 years. 3. It's only about 30-50 years ago that, if there are any waring effects from increased CO2, they will have been detected. Before the 1960s the change in CO2 concentration from the pre-industrial level was negligible, i.e. ~30 ppm or ~0.5 w/m2. How do you know if it is warmer now than 100 years or 50 years or 150 years ago? Why is accuracy so unimportant to you?We are not just looking at a single source of data, e.g. Armagh. There are lots of other records which extend back more than 150 years, e.g. CET, Uppsala, Stockholm, DeBilt etc. There are lots more which extend back more than 100 years. Most of them tell pretty much the same story. We also have ocean temperature data. We also have proxy data - such as borehole temperatures and ice core data. I didn't mean that accuracy was unimportant I meant that providing we understand what is happening then it is not as important as we might think. EG - Take a station where the readings are always 2 deg too high. Does that matter. It depends what you want. If you're just looking for a trend (i.e. whether it's warming or cooling) - it doesn't matter in the slightest. The trend will be totally unaffected. Why are you discounting tiny changes to say that the earth has warmed by the tiny amount of 0.6C in 100 years?That the earth has warmed by ~0.6 deg over 100 years is a highly significant result. It is not the same as saying Armagh or London warmed 0.6 degrees since last year. I assume you are familiar with the concept of sample size in statistics. If not, let me try to illustrate what I mean. Let's say that we suddenly found out that the whole of the US was 1 deg cooler in 2009 than we previously thought but that the temperatures in 1900 were correct. Let's also say this cooling was at a constant rate of ~0.1 deg per decade. How much effect do you think this would have on the overall trend of 0.6 deg. The answer is barely anything. The 20th century warming would still be about 0.6 deg. Why is 30 years so important to you?Already dealt with. How on earth can you give meaning to 30 years when talking about climate change while telling me accuracy is not important?Dealt with above. Do you have any scientific training?Yes - but this is irrelevant. If someone on this blog makes a valid point which debunks my opinion I don't play the qualifications card. Why do you refer me to another persons opinion who you agree with in order to inform me you dont agree with me as if people who agree with your opinion are able to know the absolute truth?I refer you to others who may be able to offer a more convincing explanation than I can give. Does the concept of independance have any meaning for you?I don't know what you mean. You have an unproven theory and you are using what appears to be a known short term warming period inside a medium term warming period inside an even longer term warming period to prove that the short term warming is created by factors fitting your theory. Meanwhile you seek to destroy any acceptance that the medium term warming period existed and thereby dont even consider the short term warming and cooling within it. You have decided that climate change is simple and the only reason it can be warming is for reasons that fit what you believe. The evidence is you refuse to believe in complexity and like to keep things simple so you can understand and imagine you know what is happening. Therefore when presented with the following since it probably supports your beliefs system you think it is able to provide the accuracy required to measure tiny changes: www.ncdc.noaa.gov/oa/climate/research/anomalies/index.phpPlease Note: In July 2009, NCDC transitioned to the use of an improved Global Land and Ocean data set (Smith et al., 2008) which allows better analysis of temperatures throughout the record, with the greatest improvements in the late nineteenth century and since 1985. Improvements in the late nineteenth century are due to improved tuning of the analysis methods.
-------------------------------------------------------------------------------- Overview NCDC's long-term mean temperatures for the Earth were calculated by processing data from thousands of world-wide observation sites on land and sea for the entire period of record of the data. Many parts of the globe are inaccessible and therefore have no data. The temperature anomaly time series presented here were calculated in a way that did not require knowing the actual mean temperature of the Earth in these inaccessible areas such as mountain tops and remote parts of the Sahara Desert where there are no regularly reporting weather stations. Using the collected data available, the whole Earth long-term mean temperatures were calculated by interpolating over uninhabited deserts, inaccessible Antarctic mountains, etc. in a manner that takes into account factors such as the decrease in temperature with elevation. By adding the long-term monthly mean temperature for the Earth to each anomaly value, one can create a time series that approximates the temperature of the Earth and how it has been changing through timeThis is the state of the art today. If you want to fund that kind of garbage privately then feel free to do so but why the hell should other people be expected to pay the salaries of people who come up with rubbish like that?
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Post by glc on Aug 18, 2009 19:47:30 GMT
You have an unproven theory and you are using what appears to be a known short term warming period inside a medium term warming period inside an even longer term warming period to prove that the short term warming is created by factors fitting your theory.
Hold on - I don't have a theory.
Meanwhile you seek to destroy any acceptance that the medium term warming period existed and thereby dont even consider the short term warming and cooling within it.
Yet more garbage about something or other. You have decided that climate change is simple and the only reason it can be warming is for reasons that fit what you believe.
No I don't believe climate change is simple. I believe some of the recent warming could be due to increased concentrations of CO2. CO2 does interact with LW radiation at wavelengths which lie broadly in the 13-17 micron range, so it's not unreasonable to think that more CO2 in the atmosphere will cause the earth to warm. That is basic physics.
The evidence is you refuse to believe in complexity and like to keep things simple so you can understand and imagine you know what is happening.
Yes I know you all like to introduce "complexities" because that gives you a "get out". You can brush it all aside in the comforting thought that because there are uncertainties no-one really knows anything. Well, sorry, but it's not like that. The radiative transfer equations which have been discussed on this blog are based on solid Physics. I repeat there is good reason to believe that more CO2 will result in higher temperatures. This has been known for more than a century.
Therefore when presented with the following since it probably supports your beliefs system you think it is able to provide the accuracy required to measure tiny changes:
You need to go and think about things and formulate in your mind where you think problems might be when measuring temperature over a given period of time.
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Post by sigurdur on Aug 18, 2009 20:17:55 GMT
I think that is what is lost in this discussion is this: 1. Can an increase in co2 cause warming. Yes it can. 2. Does an increase in co2 cause warming in the climate? NO one knows for sure if that happens or not. A lot of correlation, but as of yet, no causation. Some people believe that causation is enough to be worried. Others know that causation is not a cause to be worried about increased temps, in fact, there are some, me included, that look forward to at least a 2C warmer period as it is good for man.
I won't be alive when that happens in a few 100 years if it does, but mankind will benifit from it greatly.
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Post by magellan on Aug 19, 2009 2:22:00 GMT
glc's rendition of surface stations agreeing with satellite The NCDC record is not recognised by the WMO or the IPCC. Pielke has chosen the NCDC record to highlight a differecnce which does not exist in the GISS record. I've read the Pielke post on WUWT and, believe me, if I choose to attack it I could tear it apart. There are huge inconsistencies in his findings I'll repeat it again - and again if you like. Since the early 1990s, the trends for all 4 main data sets (GISS, Hadley, RSS and UAH) are virtually the same. The ocean areas show warming in both satellite and surface records. This cannot be due to urban heat. The satellites show warming in the troposphere which again cannot be due to urban heat. Yet Pielke cites a paper (his own) which suggests a conservative estimate for UH warming is ~0.21 deg per decade. In other words, Pielke is claiming that although the oceans and the troposphere have warmed for whatever reason, the land surface has not warmed and the only reason it shows warming is due to the siting of station thermometers. It's totally and urtterly implausible. The NCDC record is not recognised by the WMO or the IPCC. Pielke has chosen the NCDC record to highlight a differecnce which does not exist in the GISS record. That is one of the most laughable things you've come up with in a while. Second to NCDC, IIRC GISS has the next largest diversion from satellites. Where do you think GISS gets their data from? To save face you can edit the part about NCDC, WMO and IPCC before looking completely silly. You have 24 hours....... I used Pielke's NCDC chart. HadCRU is available as well. There are many institutions, research articles, media outlets and internet sources (hello socold) that use NCDC as a metric for surface temperature. Read and understand the paper before making unfounded conclusions. I'll repeat it again - and again if you like. Since the early 1990s, the trends for all 4 main data sets (GISS, Hadley, RSS and UAH) are virtually the same. Only in your mind does this mean anything, which is why you get ignored in other forums. They are diverging, period. That you can't understand the underlying problems isn't a good reason to bastardize statistics. The ocean areas show warming in both satellite and surface records. This cannot be due to urban heat. The satellites show warming in the troposphere which again cannot be due to urban heat. Yet Pielke cites a paper (his own) which suggests a conservative estimate for UH warming is ~0.21 deg per decade. AFAIK UHI does not warm the oceans, but only a charlatan can believe 0.00038 L CO2 / L air can ;D The sun warms the oceans, whether by itself increasing in heat output or mitigation by clouds etc. The problem you have is the oceans are not warming per CO2 AGW dogma. Please cite a paper from Pielke where he suggests UHI warming is ~.21 deg per decade, I think you are making it up. If you'll notice from Pielke et al, this paragraph: Table 1 also clearly shows that there has been enhanced warming over land areas when compared with ocean areas, especially in the surface temperature datasets. For example, the NCDC dataset indicates nearly three times as much warming over land areas as over ocean areas during the past thirty years. Over this same time period, the UAH lower troposphere temperature estimate indicates about half as much warming over land areas, which is contradictory to the expected global surface/lower troposphere amplification that is calculated from the lapse rate
enhancement in the global models [Santer et al., 2005, Karl et al., 2006, Douglass et al., 2007]. The global amplification ratio of 19 climate models listed in CCSP SAP 1.1 indicates a ratio of 1.25 for the models' composite mean trends and 1.19 in their composite median values over a 21-year period that is completely contained within the 30-year record used here.
and (my orange bold) Monitoring temperature at a single height will produce a significant warm bias when the atmosphere has warmed over time [Pielke and Matsui, 2005]. This effect will occur even for otherwise ideal locations for making spatially representative temperature measurements. This was documented in Lin et al. [2007] who found from observational data that monitoring long-term near-surface daily minimum temperature trends at a single level on light wind nights will not produce the same trends as for long-term temperature trends at other heights near the surface. For instance, were the data from Lin et al. [2007] to be representative of biases in other station measurements taken at one height, then about 30% of the tropospheric warming during the 20th century reported by the IPCC would be explained as the result of this factor. A warm bias would occur even for daytime maximum temperatures for land locations at high latitudes during the winter when the surface temperature profile remains stably stratified all day. The reason for a stable boundary layer warm bias can be summarized as follows The satellites show warming in the troposphere which again cannot be due to urban heat. Honestly glc, you've got your own ideas without regard to observed data. I digress. Would you mind explaining this please?
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Post by radiant on Aug 19, 2009 4:27:12 GMT
You need to go and think about things and formulate in your mind where you think problems might be when measuring temperature over a given period of time. More dishonesty. A few posts ago I was being lectured that all that was required was to imagine one room and one thermometer and find which way the trend was going because I was making the mistake that others made and thinking that accuracy was important. Anthony Watts has made the same mistake. And evidently in our Brave New World we can know things without accurate measurement. It's not a case of not wanting to measure them it's a case of knowing and managing them. Today we just know things.
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Post by icefisher on Aug 19, 2009 4:49:14 GMT
No I don't believe climate change is simple. I believe some of the recent warming could be due to increased concentrations of CO2. CO2 does interact with LW radiation at wavelengths which lie broadly in the 13-17 micron range, so it's not unreasonable to think that more CO2 in the atmosphere will cause the earth to warm. That is basic physics. The basic physics part is really it will cause the upper atmosphere to warm. But even that is a bit of a misnomer. Kind of like ocean acidification where the ocean is getting less alkaline and some 100's times more CO2 will get the oceans closer to the acid found in a typical freshwater lake or reservoir. Up in the area of the upper atmosphere where that CO2 bite is in the LW spectrum its coooooold up there. So rather than warming you are probably only talking a bit less freezin yo butt off.
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Post by glc on Aug 19, 2009 10:05:22 GMT
I'll repeat it again - and again if you like. Since the early 1990s, the trends for all 4 main data sets (GISS, Hadley, RSS and UAH) are virtually the same.
Only in your mind does this mean anything, which is why you get ignored in other forums. They are diverging, period. That you can't understand the underlying problems isn't a good reason to bastardize statistics.
Could you tell me why it doesn't mean anything and could you tell me why this point is ignored. In my experience, if you post something that's clearly wrong or irrelevant, other posters are only too ready to dive in and provide 'clarification'. You appear unable to do so - because you can't and others (including Pielke) appear unable to do so - because they can't. This is actually becoming tedious. The headline trends are the same. There is disagreement before ~1992 but that's between UAH and all other datasets not between surface and satellite, i.e. RSS disagress with UAH also. Now we can speculate on the reasons for this, but is it worth it. Since ~1992 the trends match up rather well. Is there a divergence in recent years? Possibly but it's not yet evident in the data.
The GISS anomaly for July is +0.6 but if we use the satellite baseline (1979-1998) it becomes +0.36 which is lower than the UAH anomaly of +0.41. Let's give it time, shall we, before deciding that there definitely is divergence. It seems there is divergence when GISS are high and UAH low, but not convergence when the opposite happens.
Regarding the WMO and IPCC. The WMO headline figures are from CRU. The IPCC cite all surface metrics but because the global trends are all fairly similar, i.e. ~0.17 deg per decade, they could be using any of them in their press releases. RSS is also about the same. UAH, over the same period, is lower at ~0.13 deg per decade but as already mentioned this originates in the pre-1990s period. Roy Spencer discusses this on his blog.
Let's just suppose, for the moment, that the temperatur trend * is affected by UH contamination. How much do you think it will affect the overall trend*?
* note I refer to trend not data. The data can be affected without it affecting the trend.
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Post by glc on Aug 19, 2009 10:20:08 GMT
I digress. Would you mind explaining this please?
Would you (or Christy) mind explaining the May/June dip in UAH anomalies? By my reckoning the UAH dip will have a similar effect on the global trend as a glitch over East Africa.
It could, though, be an issue related to smoothing . To check you'd need to look at trends in the wider surrounding regions.
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Post by radiant on Aug 19, 2009 12:41:42 GMT
* note I refer to trend not data. The data can be affected without it affecting the trend. Who cares about the data? The anomalies are calculated with reference to made up global mean data. Why split hairs on the details? The trend is what is important.
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Post by sigurdur on Aug 19, 2009 13:03:05 GMT
* note I refer to trend not data. The data can be affected without it affecting the trend. Who cares about the data? The anomalies are calculated with reference to made up global mean data. Why split hairs on the details? The trend is what is important. All the temperature sites do the best with what they have. The problem with this whole mess of anomaly's is that they are not accurate because the underlieing base is not accurate. Such a foolish waste of time to have a made up base, and then declare that it is correct? This is going to very simple: YOU CAN'T BUILD A HOUSE ON ICE IN THE TROPICS AND EXPECT IT TO STAND. When the footing is full of cracks and holes etc, the structure will crumble with time. Just no two ways around it.
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Post by glc on Aug 19, 2009 16:03:11 GMT
More dishonesty.
A few posts ago I was being lectured that all that was required was to imagine one room and one thermometer and find which way the trend was going because I was making the mistake that others made and thinking that accuracy was important.
Think about it. What are the possibilities. For example
1. The instrumentation may have a wide tolerance, e.g. +/- 0.2 deg. 2. The instrument may have a warm/cold bias. 3. Something may change in the surrounding evnvironment.
What are the implications for the long term trend in each of those cases. Analyse them (this should be no problem with you being a scientist and all) then show me your results preferably with error bars. You can use the example of a met station if you wish.
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Post by icefisher on Aug 19, 2009 16:13:43 GMT
Would you (or Christy) mind explaining the May/June dip in UAH anomalies? By my reckoning the UAH dip will have a similar effect on the global trend as a glitch over East Africa. It could, though, be an issue related to smoothing . To check you'd need to look at trends in the wider surrounding regions. What is really hilarious is how excited folks get over a warming trend that in 1 year varies more than its varied over 180 years and has been fluctuated like that and more for the whole 180 years. I d/l's Akasofu's paper last night (50mb) and he takes AGW apart everywhich way, whether its arctic ice, glaciers, temp records, temp proxies, treerings, cherry blossoms, iceups, breakups, boreholes; he has dozens of ways at estimating trends going back several hundred years and makes a strong case for LIA recovery amounting to a large portion of the warming we have seen. No cherrypicking here. Truth and science denialists need to suppress this paper big time as its a real embarrassment for RC and the rest of the sycophants who have been reduced to arguments that there has been no fluctuations in temperature in complete denial of an awful lot of science. This is a tremendous work that merely sets the table. Akasofu does not attempt to explain how all these variations are occuring in any way shape or form but makes a huge case for most of it being a natural variation that needs to be recognized and removed before we stop wasting money trying to pin it on a single trace gas in the atmosphere. people.iarc.uaf.edu/~sakasofu/pdf/two_natural_components_recent_climate_change.pdfRead it and weep GLC!
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Post by radiant on Aug 19, 2009 16:48:10 GMT
More dishonesty.
A few posts ago I was being lectured that all that was required was to imagine one room and one thermometer and find which way the trend was going because I was making the mistake that others made and thinking that accuracy was important.Think about it. What are the possibilities. For example 1. The instrumentation may have a wide tolerance, e.g. +/- 0.2 deg. 2. The instrument may have a warm/cold bias. 3. Something may change in the surrounding evnvironment. What are the implications for the long term trend in each of those cases. Analyse them (this should be no problem with you being a scientist and all) then show me your results preferably with error bars. You can use the example of a met station if you wish. 1. You are wanting to measure 0.6 of a degree change in 100 years. 2. You need to know the methods used 100 years ago. 3. Assuming a laboratory grade thermometer was used and the calibration chart for the thermometer was read to record the corrected temperature you may be able to get say + or - .2 accuracy. 4. You are only recording two temperatures per day. These temperatures are often related to special conditions of windlessness related to that particular site. So there is a risk the only two temperatures you record are related to particularly unique characteristics of the site that create the highs and lows of the day. Therefore it is important that local structures dont change and the thermometer is kept in a constant position. In Southern Britain and parts of NZ for example it is very rare that it is freezing on a windy day. Freezing conditions are more likely to be related to ground frost conditions where 100 yards away there is no ice due to a stream being near or the land being higher. In places like Finland you get many minus degrees regardless of the wind so on these days local influences are minor but we still get ground frosts on still days. In Armagh there appears to be a nearby newly constructed black flat roof relatively positioned under the thermometer in one of the schools or factories visible from the panaromic view. in the right still air conditions that heated air from the entire factory area will move towards the thermometer quite possibly once per summer to create a high. When the thermometers were near the new library they probably would not have been affected by that in the same way. All we know is temperatures are recently higher but we dont know why. It is pointless going into this in greater detail. These factors are well known to Meterologists who are in the buisiness of forcasting weather and do what they can. I doubt many are using a calibration graph to record the temperatures or even knows how to use one. Probably all they have is a calibration certificate for the thermometer that certifies one or two temperatures on the scale - the rest therefore having unknown precision due to the random nature of the glass. Often an ice point certificate is said to be lifetime sufficent because the same thermometer could be retested but this is unnecessary because it does not change but if it lost this is a bit pointless because the rest of the scale is unknown unless graphed against a known standard with known precision. Once the thermometer is replaced without a calibration graph you have more or less garbage for the measurement of 0.6 degrees in 100 years. UK Met offices today use a met standard alcohol low temperature thermometer and met standard mercury thermometer. There primary functions remains weather forcasting. The only way to know how accurately the met office can record temperature with reference to the centrigrade scale of freezing and boiling of water is to do the science and find out. And each lab does its best to get a sample of pure water - a more or less impossible act to begin with, and when is the boiling point of water? is it one bubble or two? It would be stirred rather than shaken at least. The practical reality is one of vaugeness to produce the certified centrigrade scale that is then used to graph the calibration chart of the mass produced thermometer. Another lab would give a different calibration. Only by using all labs can you have some idea of the precision of the graph. The point being in 100 years time this work has to be repeated by the next generation of temperature measurers. 0.6 degree is a tiny change in these circumstances of measuring a change out in the field using a mass produced device. Whatever manufacturers might say, actual calibration charts done by best practice almost never produce the claimed results. And for an 80 pound Met standard thermometer i doubt it has been calibrated so that a graph is available of that devices readings versus a best practice centrigrade measurement between freezing and boiling water. If one is available then we will know what the claimed precision will be when recording the heat content of the device. You must begin with accuracy or you would have no chance. If you consider what is involved you might not continue to look for that 0.6 degree in 100 years.
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Post by glc on Aug 20, 2009 6:54:00 GMT
people.iarc.uaf.edu/~sakasofu/pdf....mate_change.pdf
Read it and weep GLC! I have scanned the document and I'm not convinced by the argument which appears to be that there has been a constant 0.5 deg/century over the past 200 years. Akasofu uses the current surface temperature record with a few isolated long term records including the CET to make his point. However there is NOT a significant trend in the CET record between 1800 and 1900. A Least Squares fit gives a total increase of ~0.03 deg over the century. On the other hand, there is an increase of ~0.7 deg between 1900 and 2000. There's a lot more like this. But one thing did make me smile (if not actually "weep" with laughter). Look at Fig 5d on page 18, i.e. the De Bilt winter temperatures over the past millenium. Does that remind anyone of anything?
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Post by glc on Aug 20, 2009 7:09:52 GMT
1. You are wanting to measure 0.6 of a degree change in 100 years.
No I'm not - and when I asked for an analysis you haven't quite provided what I was looking for.
Try this:
Let's say we have a station which meets all your requirements with respect to measurement accuracy and local station environment and has done so for the last 30 years. Also lets assume we have sampled the temperature every minute rather than twice a day.
Ok - we now want to know how much temperatures in September have changed in the 20 years between 1986 and 2006. The mean temperatures are as follows:
Sept 1986 : 11.3 deg Sept 2006 : 16.8 deg
Conclusion : Temperatures in September have risen 5.5. deg (i.e. 2.75 deg per decade) in the past 20 years. Discuss.
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