jbg Posted February 21, 2015 Report Share Posted February 21, 2015 Climate change in real life, and relating to this as a Canadian board: Quote Link to comment Share on other sites More sharing options...
-1=e^ipi Posted February 21, 2015 Author Report Share Posted February 21, 2015 I guess I'll have to use the van Hateren method if I want to use time series analysis to get good estimates of climate sensitivity. Though one issue is that recent instrumental data is good for getting the fast response, but not so good for getting the slow response (due to not many years of observation), where as data that covers longer time periods (such as reconstructions for climate data over the past 1000 years, or paleoclimate data) is good for the slow response, but terrible for the fast response. So maybe if you want to get a good estimate of climate sensitivity, you need to use all the data: instrumental, tree ring, ice core, sedimentary core, etc. I might have to take a bit of a break before revisiting this with the van Hateren approach. Quote Link to comment Share on other sites More sharing options...
Michael Hardner Posted February 21, 2015 Report Share Posted February 21, 2015 As has been stated over and over again... climate and weather are separate things. It's pretty clear to me that people are reposting bad information on purpose now. There's no way that that message could not have sunk in yet. Quote Link to comment Share on other sites More sharing options...
TimG Posted February 21, 2015 Report Share Posted February 21, 2015 As has been stated over and over again... climate and weather are separate things.As long as alarmists use every heat wave and hurricane as "evidence" of warming you will get skeptics pointing out cold events. I wish you would show the same diligence calling out alarmists who deliberately confuse weather with climate as you show with skeptics. Quote Link to comment Share on other sites More sharing options...
Michael Hardner Posted February 21, 2015 Report Share Posted February 21, 2015 I wish you would show the same diligence calling out alarmists who deliberately confuse weather with climate as you show with skeptics. I do remember pointing this out in the past. Quote Link to comment Share on other sites More sharing options...
On Guard for Thee Posted February 21, 2015 Report Share Posted February 21, 2015 As long as alarmists use every heat wave and hurricane as "evidence" of warming you will get skeptics pointing out cold events. I wish you would show the same diligence calling out alarmists who deliberately confuse weather with climate as you show with skeptics. The hottest temperatures GLOBALLY ever recorded is not weather posing as climate. Not a hurricane, not a heat wave, not alarmist. Only facts to be dealt with and which the naysayers simply bury their heads in the sand over. Quote Link to comment Share on other sites More sharing options...
-1=e^ipi Posted February 21, 2015 Author Report Share Posted February 21, 2015 The hottest temperatures GLOBALLY ever recorded is not weather posing as climate. Not a hurricane, not a heat wave, not alarmist. Only facts to be dealt with and which the naysayers simply bury their heads in the sand over. 2014 is statistically tied with like half a dozen other years as the warmest year 'on record'. And 'on record' doesn't even go that far back. It was arguably warmer during the medeival warm period. Quote Link to comment Share on other sites More sharing options...
On Guard for Thee Posted February 21, 2015 Report Share Posted February 21, 2015 2014 is statistically tied with like half a dozen other years as the warmest year 'on record'. And 'on record' doesn't even go that far back. It was arguably warmer during the medeival warm period. You mean back in that time when they didnt have such a thing as global climate records. Quote Link to comment Share on other sites More sharing options...
TimG Posted February 21, 2015 Report Share Posted February 21, 2015 (edited) The hottest temperatures GLOBALLY ever recorded is not weather posing as climate.1) We only have records for the last 100 or so years so the hottest temperature in the last 100 years is not that interesting. 2) The records are subject to "adjustments" that exceed the size of the signal. This makes its next to impossible to draw any definitive conclusions from the data regarding the relative warmth of the 30s vs today. 3) Even if we accept the claims at face value the amount of warming has been significantly less that the models predicted. This shows that the models are not that useful guides to what is likely to happen in the future. Edited February 21, 2015 by TimG Quote Link to comment Share on other sites More sharing options...
On Guard for Thee Posted February 21, 2015 Report Share Posted February 21, 2015 1) We only have records for the last 100 or so years so the hottest temperature in the last 100 years is not that interesting. 2) The records are subject to "adjustments" that exceed the size of the signal. This makes its next to impossible to draw any definitive conclusions from the data regarding the relative warmth of the 30s vs today. 3) Even if we accept the claims at face value the amount of warming has been significantly less that the models predicted. This shows that the models are not that useful guides to what is likely to happen in the future. A post or so ago you were trying to say it was warmer in medieval times, now you agree we have no records of that. Which is it. Quote Link to comment Share on other sites More sharing options...
TimG Posted February 21, 2015 Report Share Posted February 21, 2015 A post or so ago you were trying to say it was warmer in medieval times, now you agree we have no records of that. Which is it.The absence of reliable information does not allow you to make any claims about whether the planet was warmer in medieval times. The unreliable information we do have suggests the plant could have been warmer. Whatever the truth is you are still wrong to make your claims. Quote Link to comment Share on other sites More sharing options...
On Guard for Thee Posted February 21, 2015 Report Share Posted February 21, 2015 The absence of reliable information does not allow you to make any claims about whether the planet was warmer in medieval times. The unreliable information we do have suggests the plant could have been warmer. Whatever the truth is you are still wrong to make your claims. It was you who made that claim. Quote Link to comment Share on other sites More sharing options...
TimG Posted February 21, 2015 Report Share Posted February 21, 2015 It was you who made that claim.No I did not. Quote Link to comment Share on other sites More sharing options...
On Guard for Thee Posted February 21, 2015 Report Share Posted February 21, 2015 No I did not. My apologies. It was I=e, or whatever his handle is, who made that claim. My mistake. Quote Link to comment Share on other sites More sharing options...
-1=e^ipi Posted February 21, 2015 Author Report Share Posted February 21, 2015 You mean back in that time when they didnt have such a thing as global climate records. There is tree ring data. Ice core data. Sedimentary core data. Quote Link to comment Share on other sites More sharing options...
-1=e^ipi Posted February 21, 2015 Author Report Share Posted February 21, 2015 My apologies. It was I=e, or whatever his handle is, who made that claim. My mistake. my claim was that it was arguably warmer. Not that it was warmer. I don't think the uncertainty of the data is small enough to make a definite conclusion about if current temperatures are higher or lower than the medieval warm period (though northern European temperatures were definitely higher). Quote Link to comment Share on other sites More sharing options...
On Guard for Thee Posted February 21, 2015 Report Share Posted February 21, 2015 my claim was that it was arguably warmer. Not that it was warmer. I don't think the uncertainty of the data is small enough to make a definite conclusion about if current temperatures are higher or lower than the medieval warm period (though northern European temperatures were definitely higher). Well we know its demonstrably warmer now we do actually have records, and that sea ice volumes are declining. Amundsen ay have got a lucky break with a combination of a lead and the right wind conditions to open up a channel for him. Happens all the time in the Beaufort as I have personally witnessed. Its only recently shipping has considered planning to use the NW passage as a regular route due to the deterioration of multi year ice pack. Quote Link to comment Share on other sites More sharing options...
TimG Posted February 21, 2015 Report Share Posted February 21, 2015 Well we know its demonstrably warmer now we do actually have records, and that sea ice volumes are declining.We have no reliable records prior to satellites. So the world may be warmer than the past but we don't really know. Quote Link to comment Share on other sites More sharing options...
-1=e^ipi Posted February 21, 2015 Author Report Share Posted February 21, 2015 Well we know its demonstrably warmer now we do actually have records, and that sea ice volumes are declining. Amundsen ay have got a lucky break with a combination of a lead and the right wind conditions to open up a channel for him. Happens all the time in the Beaufort as I have personally witnessed. Its only recently shipping has considered planning to use the NW passage as a regular route due to the deterioration of multi year ice pack. Please provide your the evidence that current temperatures are warmer than the medieval warm period at the 95% confidence level. Though I doubt you can do this because such conclusive evidence does not exist. Your deflection tactics are quite obvious (you are trying to bring up the NW passage and recently declining sea ice volumes as if that somehow demonstrates that current global temperatures are warmer than the medieval warm period.). The hypothesis that current sea ice volumes are less than they were during the medeival warm period has an even lower chance of being true than the hypothesis that current global temperatures are warmer than the medeival warm period since changes in ice volumes are a slow feedback to changes in global temperature. Sigh, why do I bother. The concept of uncertainty in science is probably too difficult for you to grasp. You refuse to even grasp the basics of photosynthesis and cellular respiration. We have no reliable records prior to satellites. So the world may be warmer than the past but we don't really know. To be fair, there are tree-ring reconstructions, ice-core data and sedimentary-core data. Quote Link to comment Share on other sites More sharing options...
On Guard for Thee Posted February 21, 2015 Report Share Posted February 21, 2015 Please provide your the evidence that current temperatures are warmer than the medieval warm period at the 95% confidence level. Though I doubt you can do this because such conclusive evidence does not exist. Your deflection tactics are quite obvious (you are trying to bring up the NW passage and recently declining sea ice volumes as if that somehow demonstrates that current global temperatures are warmer than the medieval warm period.). The hypothesis that current sea ice volumes are less than they were during the medeival warm period has an even lower chance of being true than the hypothesis that current global temperatures are warmer than the medeival warm period since changes in ice volumes are a slow feedback to changes in global temperature. Sigh, why do I bother. The concept of uncertainty in science is probably too difficult for you to grasp. You refuse to even grasp the basics of photosynthesis and cellular respiration. To be fair, there are tree-ring reconstructions, ice-core data and sedimentary-core data. Please provide evidence that it was warmer in the medieval, of course you cant because no evidence exists. I guess if you did understand cell respiration and photosynthesis, which I think we took in grade 6, you would also understand the closed carbon cycle. Oh well, carry on. Quote Link to comment Share on other sites More sharing options...
TimG Posted February 21, 2015 Report Share Posted February 21, 2015 (edited) To be fair, there are tree-ring reconstructions, ice-core data and sedimentary-core data.Proxy analysis for global temperatures requires proxies with: 1) wide geographic distribution 2) consistent response to temperatures. ice cores give 2) but lack 1) tree rings are basically junk. tree ring widths respond to everything from disease, to rainfall and wildlife damage. The people who collect tree rings simply throw away samples that don't track the modern temperature record which makes any subsequent statistical analysis meaningless. It is like judging a drug by throwing away data from patients that showed the drug had no effect. Edited February 21, 2015 by TimG Quote Link to comment Share on other sites More sharing options...
-1=e^ipi Posted February 21, 2015 Author Report Share Posted February 21, 2015 Please provide evidence that it was warmer in the medieval My claim wasn't that it was definitely warmer during the medieval warm period. Rather, current temperatures are within the 95% confidence interval of the temperatures during the medieval warm period. So the medieval warm period was arguably warmer. Look, just go to google and type medieval warm period temperature reconstructions or something: Quote Link to comment Share on other sites More sharing options...
-1=e^ipi Posted February 22, 2015 Author Report Share Posted February 22, 2015 @ Time - with respect to ice cores not having a wide geographic distribution, this is both true and false. It is true if you don't want to go that far back in time (various ice cores from alpine areas exist), but if you want to go back hundreds of thousands of years, then you are limited primarily to antarctica and greenland. These proxies are okay provided that you correct for them using the appropriate amplification factor (the rule of thumb is to divide the Antarctica ice core temperature anomaly data by a factor of 2). Interestingly, I was on a climate site like 2 weaks ago pressing some people on a related question (primarily, the basis of the 'rule of thumb' dividing antarctica ice core data by a factor of two). After enough pressing, I was eventually lead to a paper that reasonably answers my question (Shakun and Carlson (2010)). It seems that the geographic distribution of ice cores for recent times is decent enough to understand get a global representation of temperature and from there get estimates of the amplification factors needed to relate older ice core data to global temperatures. Of course there is also sedimentary core data, in addition to ice core data, which can give representation to equatorial parts of the earth over longer timescales. With respect to tree-ring data. It is not just the thickness of each ring that is used. But other information such as density and the ratios of certain isotopes. So you can get more than 1 dimension of information out of tree-ring data. Also, the tree-ring data is generally regressed on recent instrumental data to make estimates. The people who collect tree rings simply throw away samples that don't track the modern temperature record which makes any subsequent statistical analysis meaningless. It is like judging a drug by throwing away data from patients that showed the drug had no effect. I agree that there is plenty of reason to be skeptical of tree ring data. But that doesn't mean it can't be used to get somewhat decent estimates of past climate. Quote Link to comment Share on other sites More sharing options...
TimG Posted February 22, 2015 Report Share Posted February 22, 2015 (edited) I agree that there is plenty of reason to be skeptical of tree ring data. But that doesn't mean it can't be used to get somewhat decent estimates of past climate.The problem is with the nature of scientific institutions and the pressure to publish. It is very difficult for a scientist to throw away a set of data that cost a lot to collect simply because it does not yield statistically relevant results. It is much easier to construct dubious rationalizations that allow the data to be be used. As a result the scientific literature is filled with tree ring papers which are obviously built on invalid assumptions, however, there are scientists that will dogmatically defend these assumptions because their careers that depend on them. Edited February 22, 2015 by TimG Quote Link to comment Share on other sites More sharing options...
-1=e^ipi Posted February 22, 2015 Author Report Share Posted February 22, 2015 (edited) The problem is with the nature of scientific institutions and the pressure to publish. It is very difficult for a scientist to throw away a set of data that cost a lot to collect simply because it does not yield statistically relevant results. It is much easier to construct dubious rationalizations that allow the data to be be used. I know what you mean. I have first hand experience with corruption in science. Edited February 22, 2015 by -1=e^ipi Quote Link to comment Share on other sites More sharing options...
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