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.
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.
>Past precipitation can be used to reconstruct past palaeoclimatic temperatures. δD and δ18O is related to surface temperature at middle and high latitudes. The relationship is consistent and linear over Antarctica[9]...
I think this is also flawed, because this computation requires the ratio of the isotopes in the atmosphere at the period of interest, which we don't have. And the people making this measurement just seem to assume it would certain value derived from the present, which is also unreliable...
So yea, all things considered, pretty unreliable..
See, since it seems that you are convinced yourselves, can you tell me how accurately the past temperature can be assessed by using this method? I mean +/- how many degrees?
Also share if this accuracy requires any implicit assumptions. For example, "If we assume that X today is true then it is true back then as well" where X is not a physical constant...
See, since it seems that you are convinced yourselves, can you tell me how accurately the past temperature can be assessed by using this method? I mean +/- how many degrees?
Can you tell me how many research papers on this specific subject you have read, before coming to that conclusion?
Hint: chances are you're correct (!). Size of the error bars, timeframe(s) talked about, how data was gathered, how results were processed etc, that is what such papers are about. Educate yourself! (Wikipedia is usually a good start)
None. It goes against my common sense. That is why I am asking what accuracy can this method give. I am asking that to people who are already seemingly convinced that the methods listed (fossil records, ice-cores) can be accurate..
> That applies to things you're experiencing on a daily basis.
That we cannot accurately look into the past unless we explicitly record it, is something that I experience on a daily basis.
Seriously, if you are so convinced, then why don't you just give me an accuracy measure and reasons to support it? I am not interested in anymore articles that does not contain an explicit accuracy claims and reasons to support the same.
So please understand this. It is not that I am questioning the existence of such techniques. I am questioning their accuracy/reliability..
> So please understand this. It is not that I am questioning the existence of such techniques. I am questioning their accuracy/reliability..
That is fine. Scientists do the same, all the time.
> we cannot accurately look into the past unless we explicitly record it
Please allow me an opportunity to enlighten you:
We cannot look into the past unless it is recorded somehow.
Note the absence of "we" in the recording part. Also note "somehow" may happen in many different ways.
Sensor data, satellite measurements, ice cores, fossilized creatures captured in stone, slices of tree trunks, samples of minerals whose radioactivity decayed over millenia, history books or landscape features, are just different types of records. Each with their own set of properties (accuracy being 1 of them).
So I am aware. The "we" is important because I said "accurately". When "we" set up the recording, we can make it to record with the required precision. Inferring measurements from incidental things can give the required precision, but it should be justified.
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.
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?
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.
