How do they do it 9

[1503-44]

https://interactive.carbonbrief.org/how-proxy-data-reveals-climate-of-earths-distant-past/

 

[Latexman]

TLDR the link. A computer model?

Good Luck,
Latexman

 

There are a number of natural sources that permit scientists to estimate with reasonably precision annual weather patterns.
Ice core samples, tree rings, written records of events to name just a few.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[1503-44]

Those and a thousand others are the subject of the linked article.
Sorry I was not clear that it was a rhetorical question.

 

[IRstuff]

More like > 10,000 datasets:

https://www.ncei.noaa.gov/access/paleo-search/

But, if you're a non-believer, it's machts nichts

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[1503-44]

Yes. I wasn't really directing the thread to them, but they do have a habit of always showing up.

 

[GregLocock]

The reason they append the instrumental temperature to the proxy record is that the proxies don't show warming at the same rate. Check out Keith Briffa's series for the bristlecone proxies.

https://skepticalscience.com/Mikes-Nature-trick-hide-the-decline-intermediate.htm

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[1503-44]

"The "decline" is about northern tree-rings (width), not global temperature (degrees)"

Its not exactly like the case rests entirely on tree rings, but it is a good example.

 

[rb1957]

why would you need proxies for near term temperature ? (when you have data ... such as it is)

another day in paradise, or is paradise one day closer ?

 

[JoshPlumSE]

why would you need proxies for near term temperature ? (when you have data ... such as it is)

It's not necessarily about "need", it's about appropriateness and academic honesty. Right?

If I'm saying that the historical records shows a pattern of X based on tree rings for the last 2000 years, then tree rings are showing something different for the last 60 years then doesn't that call into question the accuracy of the tree ring data?

Said another way, if the you exclude certain data from your modeling because it would skew your results doesn't that seem like you are biasing your analysis to fit your conclusion?

I'm not calling this nefarious. But, I understand the frustration. I tend to agree with the following analysis of the issue that was cited in that link:

We do not find that it is misleading to curtail reconstructions at some point per se, or to splice data, but we believe that both of these procedures should have been made plain — ideally in the figure but certainly clearly described in either the caption or the text.

Personally, I think this is exactly the type of thing that happens when complex, theoretical data is presented in a way for the public at large to consume.

 

[rb1957]

do you mean tree rings don't track with local temp, or CO2, or rainfall ?

but they do track tree growth ... a combination of local temp, CO2, and rainfall.

another day in paradise, or is paradise one day closer ?

 

[IRstuff]

It's not the general public is going to be chasing down peer-reviewed literature to read the deets.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

IRStuff,

I demand you produce peer-reviewed reports to support your opinion!

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[JoshPlumSE]

do you mean tree rings don't track with local temp, or CO2, or rainfall ?

I mean that it is inappropriate to show a graph that uses tree ring data ONLY when it supports your conclusion, but not specifically call out your inconsistency in the footnotes.

At the very least, data manipulation like this suggests that both the historical record and the predictions based on your data have a much higher margin of error than implied.

To me, that is the big issue that we're dealing with. Too many are pretending that the predictions of what will happen and what issues that will cause is "settled science". It's a prediction based on good science and extremely complex data sets.... But, with a healthy margin of error.

 

[1503-44]

Trump didn't file his tax returns because it was "Too complicated for anyone but his accountant to understand."

 

The correspondence between different dating methods has been established within local regions with a high degree of confidence. That permits, for example, very precise dating of a 1000 year old wooden beam dredged from a bog in Denmark.

Plum,
You need to clarify what you mean by 'data manipulation'. It suggests 'cherry-picking', which in turn suggests dishonesty among researchers. Techniques being sophisticated and complex does not negate their validity.
The scientists I have met were uniformly not particularly political, nor did they bring agendas into their work, other than the agenda of increasing knowledge and understanding.
What the idiot news media does with their findings is beyond their control; unfortunately it is the MSM who mediate most information consumed by the general public. From there it goes to social media to metastasize.


"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[JoshPlumSE]

You need to clarify what you mean by 'data manipulation'. It suggests 'cherry-picking', which in turn suggests dishonesty among researchers. Techniques being sophisticated and complex does not negate their validity.

Not properly identifying the "mid-stream" change of methods in the graph and representing it as something else was inappropriate. That graph merely needed a footnote as suggested in that article that was linked to. That's the extent of my complaint for this specific data.

Note: I have a personal issue with the "larger narrative" being pushed by politicians and the media. That makes all these predictions sound like they're "settled science" when they genuinely are not. When the predictions of the past have a large deviation from what has actually happened. When the margin of error or statistical deviations are not intelligently reported on.

I know you have a defeatest attitude towards global warming. That it is already too late to correct any issues that we have and that we're inevitably headed towards total catastrophe.... That's fine. However, I'm not quite so pessimistic. Certainly there is a good chance that your predictions will come true. But, I choose to act as if we still have a chance to change things for the better and that the consequences won't be so severe. I think your type of "certainty" is one thing that drives our nation (and others) towards inaction.

 

[IRstuff]

I think your type of "certainty" is one thing that drives our nation (and others) towards inaction.

Au contraire; I think it's actually optimism/procrastination that drives inaction, the optimism that "something" will come along that will solve the problem, which is a very American attitude. We saw the inevitable arc of Hitler's Germany, but refused to do much about it, until Pearl Harbor forced us into the war.

Not that different that a real, looming issue with Social Security; we KNOW the projections, there's not much is in dispute there, but we refuse to deal with it and the giganticness of the overall debt.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[IRstuff]

this suggests that both the historical record and the predictions based on your data have a much higher margin of error than implied.

They've specifically looked at the tree ring divergence and have taken the older data and partitioned it and have found no obvious divergence elsewhen

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[JoshPlumSE]

They've specifically looked at the tree ring divergence and have taken the older data and partitioned it and have found no obvious divergence elsewhere

I did understand that from the article. But, I don't believe they offered an explanation for the divergence. Did they? If that's true then it implies some issues with the entire methodology that would greatly increase the margin of error of the historical data. Right?

IRstuff -

I think you're correct in saying that optimism is also causing inaction. I'm really referring to the EXTREME pessimism that Greta "what's her name" and Ironic_metallurgist exhibit. That's it's already too late and we're all doomed unless we immediately kill 40% of the human population and start living as subsistence level hunters and gatherers.

One of the things that I really think drives everyday people towards inaction is the "rules for thee, but not for me" type of hypocrisy all over the place. Where the mega wealthy who are complaining loudest about Global Warming do things that are diametrically opposed to there dire warnings. In particular:
a) Feel perfectly comfortable with their jet setting and high consumption lifestyle.
b) Buy up ocean front property despite telling us how much sea levels are going to rise.
c) Oppose nuclear and demand that our existing nuclear power plants get shut down, despite it being the most reliable carbon free energy source we have... other than hydro power which they often oppose as well.