Interesting: "Towards the base, the ice is more than 120,000 years old and dates back to the last interglacial period, a time when the atmospheric temperature above Greenland was 5°C warmer than today."
It also shows how crazy it would be if we get the projected 2-3 degrees average temperature increase. Even in a period where we'd expect to be going into a new ice age; instead shooting to a previously unseen high temperature.
On the other hand if we only have 2-3 degrees of warming, if that’s enough to prevent the next ice age, didn’t we just dodge a massive icy bullet? Might we not one day thank ourselves for doing something reckless and stupid that actually worked out?
Yeah a warmer climate brings all kinds of horrible changes. But food still grows in the northern hemisphere. A colder climate is arguably even worse for us.
By the way, that’s no excuse to keep doing what we’re doing. Limiting warning at 2-3 degrees will be nice. Things get really horrific above 4. At some unknown point feedback cycles really kick in and we go to 5-10 degrees and get completely fucked. We really have to not find out where that threshold is.
* 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
The Eemian climate is believed to have been warmer than the current Holocene. Changes in the Earth's orbital parameters from today (greater obliquity and eccentricity, and perihelion), known as Milankovitch cycles, probably led to greater seasonal temperature variations in the Northern Hemisphere. During the northern summer, temperatures in the Arctic region were about 2-4 °C higher than in 2011.
The hippopotamus was distributed as far north as the rivers Rhine and Thames. . . . The prairie-forest boundary in the Great Plains of the United States lay further west near Lubbock, Texas, whereas the current boundary is near Dallas. . . . Sea level at peak was probably 6 to 9 metres (20 to 30 feet) higher than today . . . .
There is definite evidence of hominins in North America 130,000 years ago (search "Cerutti mastodon"). Nobody knows if they were H. erectus, Neanderthal, Denisovan, modern humans, or "other", but with an interglacial at 125,000 years ago, it is not hard to see how they could have got here.
This raises a very critical point. Nuclear is the only dependable energy source. Fossil fuels will run out or go out of favor. Solar and wind on the other hand will become victims of the next major volcanic eruption as ash destroys them or renders them ineffective.
"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 past millennia.
Iirc, the CO2 concentration now as been pumped up higher than it was then, which is in part what is worrying because temps might then potentially shoot even higher.
Bottom line: we need large scale carbon capture quickly because even if we reach net zero CO2 will take millenia to drop back to the level it was pre-industrial revolution.
Edit: I wouldn't focus on "pre-industrial levels" specifically, the point is that there is too much now so we most likely want concentration to drop as soon as possible.
I think people who are not already familiar with the known history of the Earth find it interesting that there have been higher CO2 levels and temps than there are now.
And I agree: the history of the Earth is interesting. Which is why so many people study and work in the field of geology.
It's interesting because the whole ice cap as we know it is around 120k years ago which I don't consider the long ago on human development scale. This also appears to mean that in the past 120K there wasn't a polar ice cap. I read that as the worst case scenario we should be using for long term planning. This also may help determine how fast the ice was built and how fast it will melt.
I find it interesting because it raises questions that I don't have answers to. For example:
- What caused the temperature above Greenland to be 5°C warmer than today? Why is it cooler now compared to 120,000 years ago? What causes the interglacial periods? Is glaciation the more common state of the climate?
- The article says the ice sheet is melting at the bottom? Why? Pressure from above? Friction from movement? Heat from the Earth? Something else?
- Was the ice sheet shrinking or growing when the temperatures above Greenland were 5°C warmer than now? Does existence of the ice sheet imply that 5°C warmer for some period of time is not enough to melt the Greenland ice sheet?
- How much climate data has been lost to melting from the bottom? Is the ice sheet thickening or thinning compared 120,000 years ago? How would we know?
- How much has the Greenland land mass moved in 120,000 years due to plate tectonics? Could this have impacted the ice sheet in this short amount of time?
- Humans adapt. How did humans adapt to a climate that was warmer by up to 5°C 120,000 years ago?
- How long did the warm temperatures persist 120,000 years ago? 10,000 years? 50,000 years? Or more?
- Could a cooling climate be more worrisome to humanity than a warming one?
the drilling allows sampling of environmental components over extended period of time. this meas a historic record of, gases, ash, soot, pollen, spores, silt, insects, plant animals, metals, salts.....
It's not scientifically interesting, the glacial-interglacial cycles are pretty well established. I'm guessing they're trying to insinuate some climate change minimalism argument.
Just in case this is just a case of word confusion (which I've had before), "anthropogenic" means "caused by humans", not "occurring at the same time as humans".
People worry about accelerating climate change now because we live here now.
It’s not a theoretical science thing. We have farms and cities and towns and bridges and dams and reservoirs in particular places, and we are accelerating the depreciation of many of them. The result will be tremendous loss of wealth, movement of populations, and the associated social consequences of those.
Humanity doesn’t hate itself, we like ourselves, which is why we are so concerned about what we are doing to ourselves.
Although indeed the temperatures and GHG have been lower and higher on Earth before, that was never with the amount of humans we have now. Our economy and society is quite optimised and our infrastructure hubs are largely located on coasts. Our prosperity also relies on a large amount of sophisticated technology that is hard to replace and to bootstrap.
So although the human species will probably survive a drastic climate change, many individuals will not due to famine, lack of medical supplies and care, and war over the remaining resources.
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 spew bullshit. And the above post is just that - bullshit.
Before someone invokes the HN guidelines and talks about curious conversation, recognize that throwing phrases like 'doomsday cult' into a discussion of a serious scientific project that has hit a milestone after many years of effort has only one purpose, and that is to derail. Flagging and downvoting are all very well, but there are also times when it's necessary to call bullshit.
The earth may have survived those changes, but not all its inhabitants may have. So there definitely is still reason to worry as far as humanity is concerned.
The major ecological shifts may bring change humanity does not bounce back from.
It is also because it will result in incredible levels of migration and competition for resources in the short term (ie wars). Yes, humanity will survive but it might make global shocks like the pandemic seem very tepid by comparison.
Please correct me if I'm wrong. The amplitudes of co2 ppm seem to always have been within a certain band though, topping out at 300ppm. Right now, we're at 420ppm and increasing what looks like exponentially. [0]
I'm not saying humans won't be fine but we've never been so dependent on the stability of the climate before. People will die, get displaced, suffer economically, etc as far as I understand.
A critical piece is the speed at which the climate is warming. The Earth has had much warmer and colder periods in its history that (most) life adapted to. However, life was only able to adapt happened because those changes happened at a sufficiently slow pace. To perhaps put the current trend in the context of geologic time, there have been 5 mass extinctions in the fossil record of life on Earth. These are associated with rapid changes in climate (e.g. asteroid impacts, large volcanic eruptions). Anthropogenic climate change is driving Earth's 6th mass extinction event. To be clear: what is happening now has not happened often in Earth's history. Life has survived, but it has not been pretty. Some alarmism is warranted from the ecosystem collapse alone.
Part of the problem, which you fail to address, is the time frame when these changes take place and the possibility of the ecosystem to adapt. Yes, we've been much cooler and much warmer, with these changes taking place over thousand of years: not a couple of centuries.
Not all natural disasters can be pinned into global warming (earthquakes for example), also some weather related disasters are caused by cyclical patterns (e.g. El Niño), but certainly the higher frequency (and potency) of some weather related disasters are already linked to human influence: https://news.un.org/en/story/2021/09/1098662
Is not doomsday as the world won't change overnight, but some areas of the globe will suffer a lot from the higher intensity of the weather and this will probably create a lot of global challenges and might bring (mostly) overcome tragedies, like widespread famine, back to the news
When temperature rises slowly, ecosystems adapt in parallel to the change. When temperature rises fast, ecosystems don't. And so we have major die-offs of coral and trees, without corresponding colonization in places where they could now live.
When CO2 rises slowly, the ocean's pH is buffered by large deposits of calcium carbonate on the bottom. When CO2 rises fast, we get ocean acidification, which is on track to be the most extreme shellfish extinction event in the last 50 million years.
Therefore larger absolute past climate changes were less likely to have extreme impacts than faster present climate changes.
The short term effects are all about the slope. And the short term is all that matter to us, because if we don't pass through this bottleneck we won't have a long term (it may well be our "great filter" preventing us from spreading through the stars)
>>"The doomsday cult saying we are all going to die, or that every single heat wave and natural disaster can be pinned on extra carbon, are just yet another in a long line of apocalyptic predictors"
The problem with this argument is that 'humans' surviving, is different than 'our nice comfortable human society' surviving.
Yes, the human species as an animal that can survive by foraging, probably will survive. That isn't a great argument.
thomasahle|2 years ago
It also shows how crazy it would be if we get the projected 2-3 degrees average temperature increase. Even in a period where we'd expect to be going into a new ice age; instead shooting to a previously unseen high temperature.
slashdev|2 years ago
Yeah a warmer climate brings all kinds of horrible changes. But food still grows in the northern hemisphere. A colder climate is arguably even worse for us.
By the way, that’s no excuse to keep doing what we’re doing. Limiting warning at 2-3 degrees will be nice. Things get really horrific above 4. At some unknown point feedback cycles really kick in and we go to 5-10 degrees and get completely fucked. We really have to not find out where that threshold is.
adolph|2 years ago
The Eemian climate is believed to have been warmer than the current Holocene. Changes in the Earth's orbital parameters from today (greater obliquity and eccentricity, and perihelion), known as Milankovitch cycles, probably led to greater seasonal temperature variations in the Northern Hemisphere. During the northern summer, temperatures in the Arctic region were about 2-4 °C higher than in 2011.
The hippopotamus was distributed as far north as the rivers Rhine and Thames. . . . The prairie-forest boundary in the Great Plains of the United States lay further west near Lubbock, Texas, whereas the current boundary is near Dallas. . . . Sea level at peak was probably 6 to 9 metres (20 to 30 feet) higher than today . . . .
https://en.wikipedia.org/wiki/Eemian
angiosperm|2 years ago
orangepurple|2 years ago
wheelerof4te|2 years ago
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 past millennia.
mytailorisrich|2 years ago
Bottom line: we need large scale carbon capture quickly because even if we reach net zero CO2 will take millenia to drop back to the level it was pre-industrial revolution.
Edit: I wouldn't focus on "pre-industrial levels" specifically, the point is that there is too much now so we most likely want concentration to drop as soon as possible.
lehi|2 years ago
BurningFrog|2 years ago
The short term solution/bandaid is pumping SO2 into the stratosphere while we figure out carbon capture.
elzbardico|2 years ago
newfonewhodis|2 years ago
snowwrestler|2 years ago
And I agree: the history of the Earth is interesting. Which is why so many people study and work in the field of geology.
detourdog|2 years ago
I'm completely an armchair ponderer.
sgirard|2 years ago
- What caused the temperature above Greenland to be 5°C warmer than today? Why is it cooler now compared to 120,000 years ago? What causes the interglacial periods? Is glaciation the more common state of the climate?
- The article says the ice sheet is melting at the bottom? Why? Pressure from above? Friction from movement? Heat from the Earth? Something else?
- Was the ice sheet shrinking or growing when the temperatures above Greenland were 5°C warmer than now? Does existence of the ice sheet imply that 5°C warmer for some period of time is not enough to melt the Greenland ice sheet?
- How much climate data has been lost to melting from the bottom? Is the ice sheet thickening or thinning compared 120,000 years ago? How would we know?
- How much has the Greenland land mass moved in 120,000 years due to plate tectonics? Could this have impacted the ice sheet in this short amount of time?
- Humans adapt. How did humans adapt to a climate that was warmer by up to 5°C 120,000 years ago?
- How long did the warm temperatures persist 120,000 years ago? 10,000 years? 50,000 years? Or more?
- Could a cooling climate be more worrisome to humanity than a warming one?
rolph|2 years ago
unknown|2 years ago
[deleted]
p1esk|2 years ago
downWidOutaFite|2 years ago
unknown|2 years ago
[deleted]
robertlagrant|2 years ago
[deleted]
gameman144|2 years ago
WhitneyLand|2 years ago
I think even our ability to start fire at will is conclusively known to be only ~50,000 years ago.
monero-xmr|2 years ago
[deleted]
snowwrestler|2 years ago
It’s not a theoretical science thing. We have farms and cities and towns and bridges and dams and reservoirs in particular places, and we are accelerating the depreciation of many of them. The result will be tremendous loss of wealth, movement of populations, and the associated social consequences of those.
Humanity doesn’t hate itself, we like ourselves, which is why we are so concerned about what we are doing to ourselves.
spockz|2 years ago
So although the human species will probably survive a drastic climate change, many individuals will not due to famine, lack of medical supplies and care, and war over the remaining resources.
anigbrowl|2 years ago
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 spew bullshit. And the above post is just that - bullshit.
Before someone invokes the HN guidelines and talks about curious conversation, recognize that throwing phrases like 'doomsday cult' into a discussion of a serious scientific project that has hit a milestone after many years of effort has only one purpose, and that is to derail. Flagging and downvoting are all very well, but there are also times when it's necessary to call bullshit.
shostack|2 years ago
The major ecological shifts may bring change humanity does not bounce back from.
hnhg|2 years ago
barbazoo|2 years ago
I'm not saying humans won't be fine but we've never been so dependent on the stability of the climate before. People will die, get displaced, suffer economically, etc as far as I understand.
[0] https://www.climate.gov/news-features/understanding-climate/...
sleet_spotter|2 years ago
https://en.wikipedia.org/wiki/Extinction_event https://en.wikipedia.org/wiki/Holocene_extinction
petemir|2 years ago
dakial1|2 years ago
Is not doomsday as the world won't change overnight, but some areas of the globe will suffer a lot from the higher intensity of the weather and this will probably create a lot of global challenges and might bring (mostly) overcome tragedies, like widespread famine, back to the news
btilly|2 years ago
When temperature rises slowly, ecosystems adapt in parallel to the change. When temperature rises fast, ecosystems don't. And so we have major die-offs of coral and trees, without corresponding colonization in places where they could now live.
When CO2 rises slowly, the ocean's pH is buffered by large deposits of calcium carbonate on the bottom. When CO2 rises fast, we get ocean acidification, which is on track to be the most extreme shellfish extinction event in the last 50 million years.
Therefore larger absolute past climate changes were less likely to have extreme impacts than faster present climate changes.
mariuolo|2 years ago
nextaccountic|2 years ago
https://en.wikipedia.org/wiki/Holocene_extinction
Life will go on. Humans? Maybe. Human civilization will be disrupted for sure
Also: here's a visualization of how fast the climate changed in the last 20000 years vs today
https://xkcd.com/1732/
The short term effects are all about the slope. And the short term is all that matter to us, because if we don't pass through this bottleneck we won't have a long term (it may well be our "great filter" preventing us from spreading through the stars)
unknown|2 years ago
[deleted]
FrustratedMonky|2 years ago
The problem with this argument is that 'humans' surviving, is different than 'our nice comfortable human society' surviving.
Yes, the human species as an animal that can survive by foraging, probably will survive. That isn't a great argument.
bparsons|2 years ago
toss1|2 years ago
NONE of them happened at anything approaching the RATE of today's anthropogenic warming.
Our climate is warming literally orders of magnitude faster than any previous change. This is overwhelming the ability of ecosystems to adapt.
Moreover, this is entirely preventable — we're doing it, we can stop it.
downWidOutaFite|2 years ago
alberth|2 years ago
The concern is, during these hotter/colder periods of earth's existence - what happened to life on earth during that time?
Did populations decline? Was life nearly run into extinction (dinosaurs, etc)?