The danger of being too selective with the evidence

[Icemelt]

It seems that, as with many other scientific analysis, only those temperature measurements conforming reasonably with the norm during the past 150,000 years are being considered for this period. Spurious or wildly fluctuating results would appear to have been excluded from consideration when reaching conclusions, presumably on the basis that they were considered to be unreliable and perhaps, I suspect, because they did not conform to the current argument.

 

In principle it might seem reasonable to analyse a significant sample of results, were it not for the fact that other evidence indicates there were indeed some very dramatic fluctuations during this period, dwarfing any changes we may have experienced in the past century or two.

 

Recent, and not so recent evidence, shows that 15,000 YBP the average temperature in Central Europe may have increased by as much as 10°C in a period of only 50 years (Yet to be confirmed). However excavations have uncovered the bones, not fossils, of polar bears which at -20°C happily roamed the British Isles during the past 125,000 years, which were then of course joined to mainland Europe and buried under a mile of ice. It was not until 8,000 YBP that the sea rose sufficiently to flood the North Sea and English Channel, separating Britain from the rest of Europe and, prior to this, animals were free to seasonally migrate in and out of Britain.

 

During the construction of London’s Trafalgar Square hippopotamus bones dating back 125,000 years were also uncovered indicating sustained Thames Valley temperatures of +30°C, yet also found were Woolly Mammoth bones dating back to 60,000 indicating a much cooler climate. During the past 125,000 years we have consequently seen a variation of at least 50°C in average temperatures in Britain, yet these are not reflected in the charts of our temperature measurement analysis. One can’t help but wonder why !

 

However this year’s IPCC conclusions were based on results which were “A subset of about 29,000 data series was selected from about 80,000 data series from 577 studies. These met the following criteria: (1) Ending in 1990 or later; (2) spanning a period of at least 20 years; and (3) showing a significant change in either direction, as assessed in individual studies.”

 

So perhaps here we may have identified a serious problem with the validity of their conclusions. The recent IPCC analysis does include, and even favours (3) erratic results, yet our earlier analysis seems to suppress anything straying too far from the norm. It is therefore unsurprising it is being reported that the environment is changing faster than ever, when in fact it isn’t !

[1veedo]

I don't know how much this has to do with your little rant but the IPCC's selection is for recent climate change and has nothing to do with thousands of years of temperature records. They use these specific studies to prove that the Earth has been getting warmer, which is I'm pretty sure a fact that even you accept.

 

I'm not entirely sure why they tag 3 in there but this has nothing to do with Britain 125 thousand years ago. Also, while you're arguing that the reason these rapid temperature changes in Britain aren't reflected on historical temperature readings is because we chose data that shows mild temperature fluctuations, your second premise indicates that scientists actually chose "erratic" results which conflicts with your earlier premise.

 

Thirdly, you cannot judge the climate of our planet with just one region. So even if all this about Britain is true, it is no indicator of what the entire planet was doing during this time. I'm sure there are locals where temperatures have risen/drooped very dramatically in the past, but this does not reflect the planet as a whole.

 

PS: Some citations would be nice.

 

edit -- the IPCC quote has nothing at all to do with temperatures! (I've never read their most recent report but I went to verify the claim). They're talking about whether or not recent changes in "physical and biological systems," which we know for a fact have been changing, are caused by human activities. These studies are not global studies but have to do with individual, local, systems, and analyzing local systems that are not changing is a waste of time because the question is, "Are recent changes in physical and biological systems the result of human activities?" There are ecosystems that have been relatively unaffected and the IPCC recognizes this themselves in the report. What they're doing is scientifically valid and really should not be done any other way. This reflects more poorly on yourself then it does the IPCC because unlike you're trying to make it out to be, the IPCC is not actually "ignoring" these other reports -- they do quite the opposite, what they're ignoring them for is in establishing whether or not changes have been primarily anthropogenic.

 

Furthermore, these studies have absolutely nothing to do with your discussion about Britain. This particular premise does not, and cannot, logically precede your conclusion that temperature records are selected to support the status quo that current warming is very rapid.

 

I think you'll also find that conspiracy theories don't get you very far on these forums. The idea that scientists are covering up data is completely ridiculous.

[Icemelt]

I don't know - - - - scientists are covering up data is completely ridiculous.

Same old crap regurgitated from you as usual, yet again missing the point.

You’re just in so much of a hurry to shout down and dismiss anything that doesn’t fit your own little insulated fairyland that you can’t, or more importantly won’t, see below the surface.

This has nothing to do with covering up data or conspiracy, it has to do with balancing selectivity evenly between past and present measurements and interpretations to arrive at more accurate conclusions.

We are all very aware that local changes are not necessarily reflected globally, but Europe and Greenland are not small places and I don't think I'm being unrealistic to suggest that these anomalies probably exist globally.

Maybe, if as you say you haven’t read the IPCC report, or studied temperature anomalies outside of Narnia, perhaps you should before making your own interpretations or what they have reported.

I guess it’s time to ignore you again, which is becoming rather tedious.

Hmm - I wonder if it’s possible to filter you out!

[grifter]

ouch, what is this, a head bitting competition?

 

IN MY OPINION (see disclaimer)

 

I believe that most arguments made in science involving statistics/ evidence involve (to varying levels) "manipulation" and in some cases data becomes highly selective, despite this, it occurs on both sides of arguments, e.g. the oil company's of this world, will select data "dumbing down" global warming, and other organizations, wishing to insight change i.e. greenpeace who want a reduction in green house gas emissions will select data that shows HUGE changes in emissions, and showing the negative effects.

 

these two sides of the arguments "selective statistics" will (to varying degrees) cancel each other out, therefore this issue is only of concern when there is only one side of the argument, i.e. no counter argument, and as this is VERY rarely the case, it begs the question... what difference does it make???

[BhavinB]

This has nothing to do with covering up data or conspiracy, it has to do with balancing selectivity evenly between past and present measurements and interpretations to arrive at more accurate conclusions.

 

Perhaps your rant DOES have something to do with "conspiracy"

 

During the construction of London’s Trafalgar Square hippopotamus bones dating back 125,000 years were also uncovered indicating sustained Thames Valley temperatures of +30°C, yet also found were Woolly Mammoth bones dating back to 60,000 indicating a much cooler climate. During the past 125,000 years we have consequently seen a variation of at least 50°C in average temperatures in Britain, yet these are not reflected in the charts of our temperature measurement analysis. [b']One can’t help but wonder why ![/b]

 

You DEFINITELY believe some non-scientific agenda drives the selection of results rather than a statistical, scientific method. Thus your rant is based on a conjecture of conspiracy and cover up. stop pretending it isn't.

[insane_alien]

yeah the temp variations couldn't be the fact that britain used to be a lot further south and then experienced an iceage along with the rest of earth. oh no its got to be a CONSPIRACY theres no way the official story is the truth.

[Dak]

Same old crap regurgitated from you as usual, yet again missing the point.

You’re just in so much of a hurry to shout down and dismiss anything that doesn’t fit your own little insulated fairyland that you can’t, or more importantly won’t, see below the surface.

This has nothing to do with covering up data or conspiracy, it has to do with balancing selectivity evenly between past and present measurements and interpretations to arrive at more accurate conclusions.

We are all very aware that local changes are not necessarily reflected globally, but Europe and Greenland are not small places and I don't think I'm being unrealistic to suggest that these anomalies probably exist globally.

Maybe, if as you say you haven’t read the IPCC report, or studied temperature anomalies outside of Narnia, perhaps you should before making your own interpretations or what they have reported.

I guess it’s time to ignore you again, which is becoming rather tedious.

Hmm - I wonder if it’s possible to filter you out!

 

don't flame people, or you'll start to accumulate warning points.

 

having said that, if you click on 1veedo's username, then on 'view profile', then 'add to ignore list', you can filter his posts out.

 

I have to warn you, tho, that if you start to ignore anyone who argues against your points, you'll end up getting banned. if you're not willing to engage in honest discussion with people with differring views, then this isn't the forum for you.

 

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This has nothing to do with covering up data or conspiracy, it has to do with balancing selectivity evenly between past and present measurements and interpretations to arrive at more accurate conclusions.

 

this is what the peer-review process is good for. it forses all valid interpretations to be considered. I can guarantee you that, if what you said were valid, then some scientist would have pointed it out in a peer-reviewed paper.

 

the only way to circumvent the above is for all climate scientists to essentially conspire to bias their reporting and not point out each others flaws. so, wether you realise it or not, you are, in fact, suggesting there's a conspiracy.

 

to breifly repeat 1veedo: the bit you're talking about asked the question 'what caused the changes'; it therefore makes perfect sense to only actually examine the changes.

 

you are correct in that only examining the changes whilst asking the question 'is there an overall change' would be a biased sample, but this has not been done.

 

It is therefore unsurprising it is being reported that the environment is changing faster than ever, when in fact it isn’t !

 

source? i think you'll find that the science states quite clearly that, in fact, it is.

[Icemelt]

Well that seems to have stirred up a hornets' nest

My apologies if I've offended anyone, but I do rather object to being stifled on as soon as I kick what was intended to be an information seeking thread.

(Part posted in another thread)

My original post was stimulated by what appears to be a significant lack of global temperature data for the Pleistocene period (10K to 1.5M YBP) and it would be great to get more data if anyone knows of a source.

The apparent lack of detailed data seems very strange since it is such an important period, including as many as ten similar cycles to the one we are currently experiencing.

The available charts, which do include this period, are for much longer intervals and these dedicate less than 5% to the Pleistocene.

Exploding the available 5% to acquire more detail, produces fuzzy results with wild variations, some showing significantly faster warming and cooling than we have now. As much as 10C warming in only 50 years !

There's one interesting detailed chart I've discovered though and, even maiking allowances for the fact that it relates to Greenland, it shows significantly faster warming than at present (see below) but it would be great to acquire more detailed data for say 10K to 50K YBP as, from the data I've accumulated so far, I'm fairly certain this will confirm faster warming than we have now.

This chart comes from: http://

earthobservatory.nasa.gov/Study/Paleoclimatology_Evidence/printall.php

and the article includes some interesting stuff on wobble too.

[Icemelt]

yeah the temp variations couldn't be the fact that britain used to be a lot further south and then experienced an iceage along with the rest of earth. oh no its got to be a CONSPIRACY theres no way the official story is the truth.

I'm unaware of any significant continental drift involving Britain during the past 150,000 years. And I was referring to temperature changes in excess of the global average which obviously changed during the ice ages, so I'm not sure your comment is valid.

[Icemelt]

- having said that, if you click on 1veedo's username, then on 'view profile', then 'add to ignore list', you can filter his posts out

Thanks for the info and the warnings

Honest discussion and arguments from those with differing points of view are always very welcome, and that's my purpose in participating, to contribute and to hopefully learn from others and modify my views when appropriate. However abrupt authoritarian inflexible dismissals from the above have now become a regular occurrence, in my view discouraging contributions and suppressing discussion, so I think I'll take the risk and apply the filter.