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Post by nautonnier on May 20, 2009 1:13:34 GMT
It will take substantial recovery over many years to reverse such a trend and bring arctic ice consistantly above the trend line. The past two years have in fact compounded the decline - made the declining slope steeper, not at all reversed it. I cannot help noticing that the period of the graph is within 'the satellite era'. Can you point to any evidence that this is not part of a cycle of up and down? 1948 could have been a low point matching 2008 and before that 1918 could have been a high point. Perhaps the phase is longer and is itself a lagging indicator of PDO/AMO For someone that is consistently harping on about what is climate and what is weather - you seem to set climate trends based on very short periods. Probably because that is the only period that you have easy metrics for.
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Post by socold on May 20, 2009 19:51:48 GMT
It will take substantial recovery over many years to reverse such a trend and bring arctic ice consistantly above the trend line. The past two years have in fact compounded the decline - made the declining slope steeper, not at all reversed it. I cannot help noticing that the period of the graph is within 'the satellite era'. Can you point to any evidence that this is not part of a cycle of up and down? 1948 could have been a low point matching 2008 and before that 1918 could have been a high point. Perhaps the phase is longer and is itself a lagging indicator of PDO/AMO For someone that is consistently harping on about what is climate and what is weather - you seem to set climate trends based on very short periods. Probably because that is the only period that you have easy metrics for. I am not expecting a continued downward trend to zero just because of the last 30 years of data. I am expecting a continued downward trend to zero because I expect the arctic will continue warming this century.
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Post by tacoman25 on May 20, 2009 23:15:36 GMT
I cannot help noticing that the period of the graph is within 'the satellite era'. Can you point to any evidence that this is not part of a cycle of up and down? 1948 could have been a low point matching 2008 and before that 1918 could have been a high point. Perhaps the phase is longer and is itself a lagging indicator of PDO/AMO For someone that is consistently harping on about what is climate and what is weather - you seem to set climate trends based on very short periods. Probably because that is the only period that you have easy metrics for. I am not expecting a continued downward trend to zero just because of the last 30 years of data. I am expecting a continued downward trend to zero because I expect the arctic will continue warming this century. But you cannot answer his question, can you? We don't really know how much of that downward trend was cyclical, since our records only extend back a very short period of time.
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Post by socold on May 21, 2009 18:32:34 GMT
I am not expecting a continued downward trend to zero just because of the last 30 years of data. I am expecting a continued downward trend to zero because I expect the arctic will continue warming this century. But you cannot answer his question, can you? We don't really know how much of that downward trend was cyclical, since our records only extend back a very short period of time. I expect temperature to continue rising and therefore there will be no upturn in sea ice. This is regardless of whether arctic ice extent cycled up and down in the past.
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Post by tacoman25 on May 21, 2009 20:01:22 GMT
But you cannot answer his question, can you? We don't really know how much of that downward trend was cyclical, since our records only extend back a very short period of time. I expect temperature to continue rising and therefore there will be no upturn in sea ice. This is regardless of whether arctic ice extent cycled up and down in the past. So again, let me see if I understand you: you believe that natural cycles such as the PDO and AMO will have no further effect on either global temperatures or ice trends? Previous climate cycles are now rendered meaningless?
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jtom
Level 3 Rank
Posts: 248
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Post by jtom on May 22, 2009 2:50:26 GMT
Not only does the graph cover too short a time period from which to draw conclusions, but the y-axis should start at zero. Otherwise, it is visually misleading. I hate it when I see this done - it's a subtle attempt of trying to influence the reader's conclusions when the facts aren't as strong as the writer would like.
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Post by socold on May 23, 2009 0:47:54 GMT
Not only does the graph cover too short a time period from which to draw conclusions, but the y-axis should start at zero. Otherwise, it is visually misleading. I hate it when I see this done - it's a subtle attempt of trying to influence the reader's conclusions when the facts aren't as strong as the writer would like. Actually showing the zero line would bring home how close it is relative to how far arctic sea ice has already declined.
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Post by socold on May 23, 2009 0:51:17 GMT
I expect temperature to continue rising and therefore there will be no upturn in sea ice. This is regardless of whether arctic ice extent cycled up and down in the past. So again, let me see if I understand you: you believe that natural cycles such as the PDO and AMO will have no further effect on either global temperatures or ice trends? Previous climate cycles are now rendered meaningless? I don't believe they had much effect on ice trends to begin with, certainly they didn't on global temperature. The 20th century saw a flat trend in PDO but an increasing trend in global temperature. www.woodfortrees.org/plot/jisao-pdo/from:1900/trend/plot/hadcrut3vgl/from:1900/trend
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Post by tacoman25 on May 23, 2009 21:54:21 GMT
So again, let me see if I understand you: you believe that natural cycles such as the PDO and AMO will have no further effect on either global temperatures or ice trends? Previous climate cycles are now rendered meaningless? I don't believe they had much effect on ice trends to begin with, certainly they didn't on global temperature. The 20th century saw a flat trend in PDO but an increasing trend in global temperature. www.woodfortrees.org/plot/jisao-pdo/from:1900/trend/plot/hadcrut3vgl/from:1900/trendI am talking about multidecadal periods, which most certainly were affected by natural cycles. You continue to avoid my question: if the PDO remains in a multidecadal negative phase, as it did from 1946-76, do you believe that will effect temperature trends for the next 20-30 years?
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Post by socold on May 23, 2009 22:11:12 GMT
"the PDO remains in a multidecadal negative phase, as it did from 1946-76, do you believe that will effect temperature trends for the next 20-30 years?"
No because the PDO is a particular pattern of temperature anomolies, it isn't a cause of temperature change, it's more of an effect. PDO is already about as low as it can go and so all this particular effect is already seen on the global temperature record.
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Post by hilbert on May 23, 2009 22:40:01 GMT
Socold writes:
Pielke is pointing out that Hansen's prediction is that there is about .85 w/m^2 of non-maskable forcing, which means that the OHC has risen 10^22 J every year since 2003. If 2003 was 12*10^22, then the current OHC should be 17 or 18 * 10^22, according to Hansen's theory. Is it?
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Post by icefisher on May 23, 2009 23:22:10 GMT
No because the PDO is a particular pattern of temperature anomolies, it isn't a cause of temperature change, it's more of an effect. PDO is already about as low as it can go and so all this particular effect is already seen on the global temperature record. Loving it. Finally a testable hypothesis from Socold.
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Post by socold on May 24, 2009 7:23:21 GMT
Socold writes: Pielke is pointing out that Hansen's prediction is that there is about .85 w/m^2 of non-maskable forcing, which means that the OHC has risen 10^22 J every year since 2003. If 2003 was 12*10^22, then the current OHC should be 17 or 18 * 10^22, according to Hansen's theory. Is it? I am not aware of Hansen ever saying there would be a year on year static increase in OHC. Certainly the OHC records show noise with OHC changing many 10^22 J from one year to the next. If 2003 was 12*10^22 then this is ahead of Pielkes litmus test which puts it at 8*10^22 Joules in 2003. Pielkes litmus test actually specifies it should be currently about 13 or 14*10^22 Joules.
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Post by tacoman25 on May 24, 2009 14:39:33 GMT
"the PDO remains in a multidecadal negative phase, as it did from 1946-76, do you believe that will effect temperature trends for the next 20-30 years?" No because the PDO is a particular pattern of temperature anomolies, it isn't a cause of temperature change, it's more of an effect. PDO is already about as low as it can go and so all this particular effect is already seen on the global temperature record. Cause or effect, there is strong evidence that -PDO phases are associated with slight cooling or flat global temperatures. So are you now saying that there will be a decoupling of this relationship in the future...presumably because of CO2? And no, the PDO has certainly not been as low as it can go, just as the last La Nina was not nearly as strong as they can get. See 1954-57.
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Post by hilbert on May 24, 2009 16:36:19 GMT
wattsupwiththat.com/2009/05/24/disproving-the-anthropogenic-global-warming-agw-problem/#more-7993Last paragraph: The final question that arises is what prediction has the AGW made that has been demonstrated, and that strongly supports the theory. It appears that there is NO real supporting evidence and much disagreeing evidence for the AGW theory as proposed. That is not to say there is no effect from Human activity. Clearly human pollution (not greenhouse gases) is a problem. There is also almost surely some contribution to the present temperature from the increase in CO2 and CH4, but it seems to be small and not a driver of future climate. Any reasonable scientific analysis must conclude the basic theory wrong!!
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