History

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I'm curious (hexbear.net)

submitted 2 weeks ago by BountifulEggnog@hexbear.net to c/history@hexbear.net

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[–] BountifulEggnog@hexbear.net 4 points 2 weeks ago (1 children)

So- I'm actually not too familiar with how precise ice core measurements are. If you have something specific you think I should read I'd love to see. I'm also recovering from getting my wisdom teeth out, so I can't spend too long looking for information.

this (preprint) paper says:

broadly speaking, the shortest resolvable signal at high-accumulation sites is about one decade Trudinger, Etheridge, et al. 2002). At the lowest accumulation sites, centennial-scales features are markedly smoothed but still resolvable Nehrbass-Ahles et al. 2020

The British Antarctic Survery says:

The fastest natural increase measured in older ice cores is around 15ppm (parts per million) over about 200 years. For comparison, atmospheric CO2 is now rising 15ppm every 6 years.

Which- to me- says it jumping 100+ ppm for a few decades and then returning would leave evidence behind? And like, why would it jump so drastically?

I don't know, sorry if this isn't a lot of information, I really need to go lay down now.

[–] CarbonScored@hexbear.net 1 points 2 weeks ago

Nah that's fair, and I certainly have no idea what I'm talking about either. But my understanding is that "ice core data" is a compilation of data from various ice core sampling, including those 'lowest accumulation sites' where they're saying you can only measure to the precision of centuries.

Again, I don't know, but I'm assuming we don't have "high accumulation" ice core data for all of that history, so jumping 100+ ppm for a few decades and then falling again wouldn't necessarily show up in those low accumulation sites.