Regarding the divergence of proxy and instrument temps in the latter half of the 20th century?
Question by Marc G: Regarding the divergence of proxy and instrument temps in the latter half of the 20th century?
If there is a divergence between proxy and instrument temperature data, what conclusions am I to draw?
If the proxies are not accurate in the current decades (compared to instruments), then how can I be assured that the historical proxies are accurate?
If the instruments are not accurate in current decades (compared to proxies), then how can I be assured that instrumental data is accurate?
It appears that there is a lot of work being done to eliminate this divergence, but it appears to be mathematical in nature. Is anyone working on refining the experimental parameters in the determination of temperature via proxy analysis?
Hopefully this link works…..
I can’t fix the link, I think you need access to the AGU papers.
You don’t have access to the AGU journals?
Here is a link that may work. It is for the abstract:
I don’t know if it will work, since it is via the AGU as well.
Answer by Keith P
Well, the link doesn’t work, sorry.
There might be a lot of reasons for proxy divergence, depending on the proxy. But I suspect that what you’re concerned with most is tree-ring temperature proxies. The maximum density of a tree-ring has been shown to be a good proxy for overall summer-spring temperature in a given year.
Tree-ring proxies have broken down in the latter 20th century, and this is believed to be due to the effects of air pollution, principally ozone and its influence on UV radiation. Fortunately, we have actual thermometer records from this period, so the breakdown is not terribly significant to paleoclimate science.
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