But there is no way to confirm that those methods are accurate...

Yes there are. Scientists compare the measurements from both methods in the time when there's data from both. For example ice cores formed last decade should match direct temperature measurements from last decade. It's the same way the oldest rings from living trees are matched against the newest rings from tree fossils, and radiocarbon dating is checked against all of that.

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qsera 2 hours ago | parent [-]

That does not look very reliable to me, because that implies certain things are only affected by ambient temperature.

Btw, Can you tell me how ancient temperature is measured from ice cores? My lookup only says we can detect atmospheric composition, and not temperatures from the ice cores.

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TYPE_FASTER an hour ago | parent | next [-]

> Btw, Can you tell me how ancient temperature is measured from ice cores?

https://www.antarcticglaciers.org/glaciers-and-climate/ice-c...

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RetroTechie 2 hours ago | parent | prev | next [-]

Air bubbles from ancient atmosphere caught in ice -> historic CO2 levels -> historic average global temps.

This is fairly 1:1 linkage, and the Earth-heating effect of atmospheric CO2 was established in what, early 20th century or so?

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inigyou 2 hours ago | parent | prev [-]

It seems like you're on the trajectory to refuting all historical measurements altogether. In that case, I can't help you. Good luck. I suggest the philosophy of Last Tuesdayism, it may interest you.

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qsera 2 hours ago | parent [-]

Not really.

I only reject using them for certain things that require vastly more reliable data. And I am not making the mistake of relying on unreliable data just because it is the best we can manage.

Also why don't you answer my question about ice cores?

	▲	inigyou an hour ago \| parent [-]
		I'm not an ice core scientist. I suggest you ask them for detailed specifications. But the way you have posed the question strongly suggests that you will not be satisfied with any possible answer. Anything short of your eyes laying upon a thermometer will always be "not reliable enough", and thermometers only record the current temperature.