4 ms·

70 metres?? I've never heard that before. Source?

jammi 9y ago
It's been around, but not quoted as often as the 8m of Greenland. The reason is that earlier they didn't think Antarctica would have considerable amounts of melt in a short (100-200 years) timeframe, but now it seems it's melting almost as quickly as continental ice everywhere, which means mere decades will be significant.
- njarboe 9y ago
  The western part of Antartica has many fast moving glaciers, some grounded below sea level, that might speed up with global warming. This part is likely to dump a bunch of water into the ocean in the next 1-2 hundred years, but it is only about 10% of the Antarctic water/ice volume. The Eastern side is much thicker and larger and looks like it might actually increase in volume with climate warming.
  - madaxe_again 9y ago
    It’s an intensely complex system. All that you say is true, but: Warming sea water due to decreased salinity and infractions through the circumpolar current result in increased precipitation, which as you say results in an increase in volume of land ice - however this volume is accruing inland, while the coastal feet of glaciers and ice shelves continue to be undercut by said warmer water, which then allows their collapse, which allows increased flow, which allows retreat. Now - the worrying possibility which arises is that the combination of more on shore mass and less off/near shore buttressing will result in a net increase in flow, which will then contribute further to the positive feedback loop. Honestly, nobody knows, our models are nowhere near granular enough. I prefer to err on the side of caution, and take a pessimistic view, but that’s just me.
  - jammi 9y ago
    I was referring to this new study of faster than previously thought rate, but it speaks nothing of volumes, just ice retraction speed. I think they'll post something with updated melt rate by volume at some point once they've calculated it. https://sci-hub.tw/10.1038/s41561-018-0082-z https://sci-hub.tw/10.1038/s41561-018-0082-z
tajen 9y ago
Gravity means oceans are attracted to the icecaps. When icecaps melt, the level around them could even lower! and Europe might not even see much raise, because the natural equilibrium of oceans without icecaps is to have higher levels than today nearer to the equator. So I’m barely surprised with a 70m estimate due to gravity effects.
sulam 9y ago
70M is well within the scope of the historical record. The models don’t project it. Personally, I’m trusting what the data shows happened last time the atmosphere had this much carbon in it over what our models show. And the data isn’t pretty.
- pdonis 9y ago
  > 70M is well within the scope of the historical record. What historical record are you talking about? > Personally, I’m trusting what the data shows happened last time the atmosphere had this much carbon in it over what our models show. What data are you talking about?
  - sulam 9y ago
    Sorry, didn't see this -- you can research this yourself fairly easily once you know the right terms. You're looking for eustatic sea level as it correlates to CO2. I find people who research this themselves come away more convinced than if I just tell you the data or link to one specific study.

It's been around, but not quoted as often as the 8m of Greenland. The reason is that earlier they didn't think Antarctica would have considerable amounts of melt in a short (100-200 years) timeframe, but now it seems it's melting almost as quickly as continental ice everywhere, which means mere decades will be significant.

njarboe 9y ago
The western part of Antartica has many fast moving glaciers, some grounded below sea level, that might speed up with global warming. This part is likely to dump a bunch of water into the ocean in the next 1-2 hundred years, but it is only about 10% of the Antarctic water/ice volume. The Eastern side is much thicker and larger and looks like it might actually increase in volume with climate warming.
- madaxe_again 9y ago
  It’s an intensely complex system. All that you say is true, but: Warming sea water due to decreased salinity and infractions through the circumpolar current result in increased precipitation, which as you say results in an increase in volume of land ice - however this volume is accruing inland, while the coastal feet of glaciers and ice shelves continue to be undercut by said warmer water, which then allows their collapse, which allows increased flow, which allows retreat. Now - the worrying possibility which arises is that the combination of more on shore mass and less off/near shore buttressing will result in a net increase in flow, which will then contribute further to the positive feedback loop. Honestly, nobody knows, our models are nowhere near granular enough. I prefer to err on the side of caution, and take a pessimistic view, but that’s just me.
- jammi 9y ago
  I was referring to this new study of faster than previously thought rate, but it speaks nothing of volumes, just ice retraction speed. I think they'll post something with updated melt rate by volume at some point once they've calculated it. https://sci-hub.tw/10.1038/s41561-018-0082-z https://sci-hub.tw/10.1038/s41561-018-0082-z

tajen 9y ago

Gravity means oceans are attracted to the icecaps. When icecaps melt, the level around them could even lower! and Europe might not even see much raise, because the natural equilibrium of oceans without icecaps is to have higher levels than today nearer to the equator. So I’m barely surprised with a 70m estimate due to gravity effects.

sulam 9y ago

70M is well within the scope of the historical record. The models don’t project it. Personally, I’m trusting what the data shows happened last time the atmosphere had this much carbon in it over what our models show. And the data isn’t pretty.

pdonis 9y ago
> 70M is well within the scope of the historical record. What historical record are you talking about? > Personally, I’m trusting what the data shows happened last time the atmosphere had this much carbon in it over what our models show. What data are you talking about?
- sulam 9y ago
  Sorry, didn't see this -- you can research this yourself fairly easily once you know the right terms. You're looking for eustatic sea level as it correlates to CO2. I find people who research this themselves come away more convinced than if I just tell you the data or link to one specific study.