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Ice core scientists in East Greenland reach bedrock

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Re: Ice core scientists in East Greenland reach bedrock

#201

Post by arp242 »

briantakita wrote: post #115
anigbrowl wrote: post #99

Earlier quoted context omitted.

The doomsday cult Oh shut it. You can't have any knowledge at all about this issue and not appreciate that the problem is not temperature as such but the rapidity of the change - over 150 years rather than 15000. Your troll post is an insult to intelligence. Folks, don't waste your time trying to reason with such bad-faith arguments. It's a form of theft, because the time cost to refute bullshit is about 10x that to…

You seem angry, so I'm going to try to explain (from my perspective) why someone may have the perception that you reacted to. There is plenty of criticism over relying on mathematical models that fail to accurately predict the future (all of the glaciers were predicted to have melted 3 years ago, snow was supposed to have been a thing of the past, etc.), cherry picking data, questionable measurement & sampling, not c…

> all of the glaciers were predicted to have melted 3 years ago

I don't think any mainstream models predicted that? Which model was that?

Also remember that our actions are influenced by models. "If current trends persist, then in 20 years [...]" may very well be true, but if we take action based on those predictions (e.g. change the trend) then the outcome will be different.

You can see this clearly in population levels of things like elephants[1] or whales[2]: people who were predicting the extinction of whales and elephants weren't wrong.

[1]: https://ourworldindata.org/grapher/african-elephants

[2]: https://www.researchgate.net/figure/General-estimated-popula...

Re: Ice core scientists in East Greenland reach bedrock

#202

Post by hanniabu »

samstave wrote: post #117

There is a design for an ice-melting-slurry-bot that could be made, where the outer diameter of the bore is melted by heat/lasers - where the lasers/heat is also projected into a cone at the point of the bore-ing machine, where the center pipe is a vacuum to slurp up the slurry as it melts the ice around the bore-head...

That would ruin the core samples

Re: Ice core scientists in East Greenland reach bedrock

#203

Post by mschuster91 »

wheelerof4te wrote: post #183
adolph wrote: post #72

Earlier quoted context omitted.

120k years ago in context: * 170,000 years ago: humans are wearing clothing by this date. * 125,000 years ago: the peak of the Eemian interglacial period. * ~120,000 years ago: possibly the earliest evidence of use of symbols etched onto bone * 75,000 years ago: Toba Volcano supereruption that may have contributed to human populations being lowered to about 15,000 people https://en.wikipedia.org/wiki/Timeline_of_preh…

"75,000 years ago: Toba Volcano supereruption that may have contributed to human populations being lowered to about 15,000 people." The key question is: How much CO2 did that super-eruption emit into the atmosphere? In our hurry to attribute climate change to our meager impact on this planet, we tend to forget what horrors an eruption of this magnitude can cause. And who knows how many of them happened during the pas…

> And who knows how many of them happened during the past millennia.

We at least have a significantly large list of what we know [1] - that's part of the purpose of core drilling, the ash deposits worldwide can be linked together to estimate where ash traveled to. Also, craters and their surrounding can be drilled into to determine eruption events.

[1] https://en.wikipedia.org/wiki/List_of_large_volcanic_eruptio...

Re: Ice core scientists in East Greenland reach bedrock

#204

Post by staunton »

wheelerof4te wrote: post #183
adolph wrote: post #72

Earlier quoted context omitted.

120k years ago in context: * 170,000 years ago: humans are wearing clothing by this date. * 125,000 years ago: the peak of the Eemian interglacial period. * ~120,000 years ago: possibly the earliest evidence of use of symbols etched onto bone * 75,000 years ago: Toba Volcano supereruption that may have contributed to human populations being lowered to about 15,000 people https://en.wikipedia.org/wiki/Timeline_of_preh…

"75,000 years ago: Toba Volcano supereruption that may have contributed to human populations being lowered to about 15,000 people." The key question is: How much CO2 did that super-eruption emit into the atmosphere? In our hurry to attribute climate change to our meager impact on this planet, we tend to forget what horrors an eruption of this magnitude can cause. And who knows how many of them happened during the pas…

Volcanoes aren't about the CO2, they're about the ash which blocks out the sun and makes it colder.

Re: Ice core scientists in East Greenland reach bedrock

#206

Post by sedatk »

delecti wrote: post #68
sedatk wrote: post #20

Earlier quoted context omitted.

Yeah, DNA in ice has a half-life of a million years. Seems very much possible.

Where are you getting that figure? Everything I had ever read on the subject puts the half-life at more like 500 (five-hundred) years. While doing a quick double-check for this comment, it seems there was one sample with the unexpectedly long observed half-life of 15,000 years, still a couple orders of magnitude less than a million years. https://en.wikipedia.org/wiki/Ancient_DNA#Non-human_aDNA

That’s room temperature. Frozen DNA is significantly more resilient. https://www.pnas.org/doi/10.1073/pnas.0702196104

Re: Ice core scientists in East Greenland reach bedrock

#207

Post by __MatrixMan__ »

javajosh wrote: post #189
anigbrowl wrote: post #110

Earlier quoted context omitted.

A lot of modeling is moving toward Julia, so if you don't want to give money to Mathworks here are some alternatives: https://juliaclimate.github.io/Notebooks/

Note that the individual license for Matlab is $149/year [0], which isn't crazy IMHO. 0 - https://www.mathworks.com/pricing-licensing.html?prodcode=ML...

Given the added burdens of...

- managing licenses across multiple devices

- limiting the people you can share code with to ones that are willing to deal with licenses

- budgeting for an ongoing subscription / renewing as needed

...I'd say that even $10/year is too much. Ecosystems that create collaboration barriers like these are no place for important work.

Re: Ice core scientists in East Greenland reach bedrock

#208

Post by pmayrgundter »

wheelerof4te wrote: post #183
adolph wrote: post #72

Earlier quoted context omitted.

120k years ago in context: * 170,000 years ago: humans are wearing clothing by this date. * 125,000 years ago: the peak of the Eemian interglacial period. * ~120,000 years ago: possibly the earliest evidence of use of symbols etched onto bone * 75,000 years ago: Toba Volcano supereruption that may have contributed to human populations being lowered to about 15,000 people https://en.wikipedia.org/wiki/Timeline_of_preh…

"75,000 years ago: Toba Volcano supereruption that may have contributed to human populations being lowered to about 15,000 people." The key question is: How much CO2 did that super-eruption emit into the atmosphere? In our hurry to attribute climate change to our meager impact on this planet, we tend to forget what horrors an eruption of this magnitude can cause. And who knows how many of them happened during the pas…

The figure I've found is 2800 km^3 of approximately granite, which at 2.7 tonnes per cubic meter gives about a billion gigatons ejecta.

I've never found a CO2 estimate, but did find that it's a significant amount of that mass, as is SO2.

It wasn't worth me doing more of a sketch since it's not clear how to model the effects of such a massive system.

I was struck tho, that the magnitude of this and a few other events in the not too distant past, are vastly larger than even all put nuclear war

It's not clear to me that our CO2 emissions are very significant in comparison

Re: Ice core scientists in East Greenland reach bedrock

#209

Post by gottorf »

adhesive_wombat wrote: post #167
nonethewiser wrote: post #154

Earlier quoted context omitted.

“Natural concentration” is not the right way to look at it because there are higher concentrations that predate the industrial revolution and humans. The all time high (that we know of) is from about 350,000 years ago. This was by all means natural and pre industrial revolution.

"The only known natural concentration empirically compatible with long-term human civilisation". "The planet did exist/will exist just fine without us" is a pretty worn truism. You might as well wryly note that water isn't natural because everything was hydrogen once.

> empirically compatible with long-term human civilisation

Empirically observed, atmospheric CO2 went from ~320ppm to ~410ppm from 1970 to 2020[0], during which period the human population more than doubled from ~3.7B to ~7.8B and yet deaths caused by climate dropped threefold[1] (not 1/3 the rate; 1/3 in absolute number).

[0]: https://www.climate.gov/news-features/understanding-climate/...

[1]: https://library.wmo.int/doc_num.php?explnum_id=10989

Re: Ice core scientists in East Greenland reach bedrock

#210

Post by pmayrgundter »

mschuster91 wrote: post #203
wheelerof4te wrote: post #183

Earlier quoted context omitted.

"75,000 years ago: Toba Volcano supereruption that may have contributed to human populations being lowered to about 15,000 people." The key question is: How much CO2 did that super-eruption emit into the atmosphere? In our hurry to attribute climate change to our meager impact on this planet, we tend to forget what horrors an eruption of this magnitude can cause. And who knows how many of them happened during the pas…

> And who knows how many of them happened during the past millennia. We at least have a significantly large list of what we know [1] - that's part of the purpose of core drilling, the ash deposits worldwide can be linked together to estimate where ash traveled to. Also, craters and their surrounding can be drilled into to determine eruption events. [1] https://en.wikipedia.org/wiki/List_of_large_volcanic_eruptio...

Here's a study:

The size and frequency of the largest explosive eruptions on Earth, Mason 2004

https://www.researchgate.net/publication/227000709_The_size_...

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