>>14025610Ice core scientist here, you are full of shit
>old ice samples are not airthey are trapped atmospheric air from the past
>im cool with comparing core to core but even then location and time of extraction seriously matters a lotLocation does not matter for CO2. See pic related comparing measurements from Law Dome (East Antarctica coast, Australian ice core), WAIS (West Antarctic Divide, US ice core), EDML (East Antarctica Dronning Maud Land, EU ice core), all drilled and measured over 20 years.They all spline nicely into known atmospheric measurement from south pole station. Pic related. Source
Rubino, M., et al. "Revised records of atmospheric trace gases CO2, CH4, N2O, and ?13C? CO2 over the last 2000 years from Law Dome, Antarctica, Earth Syst. Sci. Data, 11, 473–492." (2019).
Just for the sake of education
>anon, how do we know that bubbles you measure in ice cores are atmospheric samples from the past and unalteredWe know because each ice core site has different accumulation and temperature, which gives us different timescale (age vs. depth). If the CO2 concentration is altered by some chemical or physical process, you would expect the alteration would grow over time/depth. Instead, we measure ice from the same time (regardless of depth) at different sites, from different ice core lab across the world, since the 1980s to today, we've been measuring CO2 in ice for 40 years and we dont see any offset beyond the analytical uncertainty. This is also how we figure out that CO2 record from Greenland ice core is not reliable, because they are more site dependent and show clear in situ production signal from dirtier (more dust and organics impurities) in Greenland
