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The rate of temperature change happening currently is much greater than anything in the geologic record. What use it is to ponder about what has triggered an i

by pavlov 2y ago

The rate of temperature change happening currently is much greater than anything in the geologic record. What use it is to ponder about what has triggered an ice age in the past, when that mechanism can’t possibly counteract what’s happening now? It’s like thinking about starting blood pressure medication when you’re having a heart attack right now.

yobbo 2y ago
I don't think ice-core measurements give year-by-year resolution good enough to determine this, but it would be interesting to know if someone proved it.
jmyeet 2y ago
That's not true [1]: > There are twenty-five of these distinct warming-cooling oscillations (Dansgaard 1984) which are now commonly referred to as Dansgaard-Oeschger cycles, or D-O cycles. One of the most surprising findings was that the shifts from cold stadials to the warm interstadial intervals occurred in a matter of decades, with air temperatures over Greenland rapidly warming 8 to 15°C (Huber et al. 2006). Furthermore, the cooling occurred much more gradually, giving these events a saw-tooth shape in climate records from most of the Northern Hemisphere (Figure 1). The last time I brought this up, someone said (paraphrased) "that's only over Greenland". Yeah, the place they did measurements. Do you really think a change in air temperature of 8-15C over decades is repeatedly localized in just one place? [1]: https://www.nature.com/scitable/knowledge/library/abrupt-climate-change-during-the-last-ice-24288097/ https://www.nature.com/scitable/knowledge/library/abrupt-cli...
- fwip 2y ago
  Well, the link you cite puts forward 2 hypotheses that could explain localized temperature change in Greenland, and does not mention "maybe this was global temperature change."
- Timon3 2y ago
  > Do you really think a change in air temperature of 8-15C over decades is repeatedly localized in just one place? I don't understand your point. This isn't a question where we have to extrapolate from this one study - you can look at similar measurements done in other places and answer this question once and for all. Instead, you simply declare the hypothesis wrong, because...? You don't bring up an argument, you just ask whether others really think that.
- defrost 2y ago
  > Do you really think a change in air temperature of 8-15C over decades is repeatedly localized in just one place? Sure .. we can see this kind of "stutter" in dynamic environments all the time, vortexes "pulsing" in stream water for example. The "rapid warming" followed by "slow cooling" pattern speaks to a lower tempreture being the long term natural stable temp. for the local region duringthat much longer period .. but interrupted by a pulsing in the climatic cell stability that routinely brings warmth in from the equatorial zone - likely via water currents, possibly via air currents. Such things can happen during stable global mean land|sea energy levels as that's literally just an average of the activity of all the cells across the planet.

by pavlov 2y ago

yobbo 2y ago

I don't think ice-core measurements give year-by-year resolution good enough to determine this, but it would be interesting to know if someone proved it.

jmyeet 2y ago

That's not true [1]: > There are twenty-five of these distinct warming-cooling oscillations (Dansgaard 1984) which are now commonly referred to as Dansgaard-Oeschger cycles, or D-O cycles. One of the most surprising findings was that the shifts from cold stadials to the warm interstadial intervals occurred in a matter of decades, with air temperatures over Greenland rapidly warming 8 to 15°C (Huber et al. 2006). Furthermore, the cooling occurred much more gradually, giving these events a saw-tooth shape in climate records from most of the Northern Hemisphere (Figure 1). The last time I brought this up, someone said (paraphrased) "that's only over Greenland". Yeah, the place they did measurements. Do you really think a change in air temperature of 8-15C over decades is repeatedly localized in just one place? [1]: https://www.nature.com/scitable/knowledge/library/abrupt-climate-change-during-the-last-ice-24288097/ https://www.nature.com/scitable/knowledge/library/abrupt-cli...

fwip 2y ago
Well, the link you cite puts forward 2 hypotheses that could explain localized temperature change in Greenland, and does not mention "maybe this was global temperature change."
Timon3 2y ago
> Do you really think a change in air temperature of 8-15C over decades is repeatedly localized in just one place? I don't understand your point. This isn't a question where we have to extrapolate from this one study - you can look at similar measurements done in other places and answer this question once and for all. Instead, you simply declare the hypothesis wrong, because...? You don't bring up an argument, you just ask whether others really think that.
defrost 2y ago
> Do you really think a change in air temperature of 8-15C over decades is repeatedly localized in just one place? Sure .. we can see this kind of "stutter" in dynamic environments all the time, vortexes "pulsing" in stream water for example. The "rapid warming" followed by "slow cooling" pattern speaks to a lower tempreture being the long term natural stable temp. for the local region duringthat much longer period .. but interrupted by a pulsing in the climatic cell stability that routinely brings warmth in from the equatorial zone - likely via water currents, possibly via air currents. Such things can happen during stable global mean land|sea energy levels as that's literally just an average of the activity of all the cells across the planet.