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chasil 16 hours ago [-]
Most people do not know that we are in an icehouse phase, which is rare.
Earth spends most of its time in greenhouse phases.
"A "greenhouse Earth" is a period during which no continental glaciers exist anywhere on the planet... Earth has been in a greenhouse state for about 85% of its history.
"Earth is now in an icehouse state, and ice sheets are present in both poles simultaneously... Earth's current icehouse state is known as the Quaternary Ice Age and began approximately 2.58 million years ago... Earth is expected to continue to transition between glacial and interglacial periods until the cessation of the Quaternary Ice Age and will then enter another greenhouse state."
We'll be much closer to a greenhouse earth than a glacial earth if we get that 4°C warming, so the distinction is more academic than practical in most contexts. What's a century here or there in geologic time?
timschmidt 13 hours ago [-]
The Cambrian and Eocene reached around +14C compared to today[1]. Two of the warmest periods in Earth's history, granted. But life thrived. Governments, private property ownership, civilization, not as battle tested.
Our bodies won't be able to handle a temperature regime that hot overall. The factor to research is Wet Bulb Temperature Effect. Basically our bodies are like sports cars and keeping our body cool is a challange under high humidity with temperature near our body temp.
UNIVERSITY PARK, Pa. — As climate change nudges the global temperature higher, there is rising interest in the maximum environmental conditions like heat and humidity to which humans can adapt. New Penn State research found that in humid climates, that temperature may be lower than previously thought.
It has been widely believed that a 35°C wet-bulb temperature (equal to 95°F at 100% humidity or 115°F at 50% humidity) was the maximum a human could endure before they could no longer adequately regulate their body temperature, which would potentially cause heat stroke or death over a prolonged exposure.
Wet-bulb temperature is read by a thermometer with a wet wick over its bulb and is affected by humidity and air movement. It represents a humid temperature at which the air is saturated and holds as much moisture as it can in the form of water vapor; a person’s sweat will not evaporate at that skin temperature.
But in their new study, the researchers found that the actual maximum wet-bulb temperature is lower — about 31°C wet-bulb or 87°F at 100% humidity — even for young, healthy subjects. The temperature for older populations, who are more vulnerable to heat, is likely even lower.
interstice 3 hours ago [-]
This explains something about why I haven't understood casually mentioning 40c+ temps, 34c in Hong Kong with no breeze is about as much as I can handle.
timschmidt 4 hours ago [-]
> Our bodies won't be able to handle a temperature regime that hot overall. The factor to research is Wet Bulb Temperature Effect.
That's a problem at the Equator, but not at the higher latitudes.
SAI_Peregrinus 2 hours ago [-]
It's a problem anywhere, just that the dry bulb temperature needed to reach a given wet bulb temperature goes up as humidity goes down.
timschmidt 2 hours ago [-]
It's a problem anywhere that temperatures reach that high. Higher latitudes have colder climates. Hence, not a problem. If it becomes a problem, people move toward the poles. No longer a problem.
Earth would have to experience > +35 to +50C for the poles to be uninhabitable due to heat.
clark_dent 2 hours ago [-]
> Higher latitudes have colder climates.
Not reliably, not continually, and much less often when you dump enough energy into the atmosphere to disrupt major wind patterns.
British Columbia hitting 121°F/49.6°C at 50°N latitude would sort of suggest your generalization doesn't hold true anymore.
timschmidt 2 hours ago [-]
Yes, polar regions are reliably colder than equatorial regions. Lytton, BC hit the temperature you cite for one day on Tuesday, June 29, 2021. That's a sign of warming, and we should expect more warm days than in the past at any given lattitude. But it is not evidence against the general case that polar regions have colder climates than equatorial regions.
Hmm. I do like civilization. How about humans, would human life thrive?
timschmidt 12 hours ago [-]
No reason not. It would push human habitable zones into the high mid-latitudes and subpolar regions though. 55–65° N/S would be closest to comfortable temperatures. So, northern Canada and Russia, Greenland, Antarctica.
The mad rush to get there would likely extract a heavy toll.
rwyinuse 12 hours ago [-]
The main problem is agriculture. If rain patterns get severely disrupted in most of world's current breadbaskets, it takes time to increase production in areas that may now have more favourable climate. During that time lots of people would starve.
Rain patterns and extreme weather events are the things to really worry about. Temperature changes alone can be mostly dealt with by planting different crops.
reverius42 12 hours ago [-]
Oh, yeah, like even if it's survivable for humanity in general, it's going to kill billions of humans.
timschmidt 12 hours ago [-]
No doubt the transition period would likely involve more death than most catastrophes in history. In part because there are simply more people. Available sunlight is also less nearer the poles, which already affects agriculture in places like Greenland. Crops would shift. We'd be more dependent on energy and supplemental light for certain crops. Adjustment would be difficult. But quite a bit of land would still be habitable.
Throaway199999 6 hours ago [-]
Disease and parasitic life would also explode in all previously-habitable parts of the Earth due to increased temp.
reverius42 12 hours ago [-]
Interesting. Paying close attention to geopolitics lately, it kind of seems like we're already in a slow-motion mad rush to own these places. Remember when Trump almost invaded Greenland?
timschmidt 12 hours ago [-]
Certain investment firms purchased cold-weather ports which were iced in 8 months a year, 20 years ago, which now operate nearly year-round.
reverius42 11 hours ago [-]
Sounds like a good long term investment. And maybe not that long term!
exe34 10 hours ago [-]
> The mad rush to get there would likely extract a heavy toll.
Climate refugee situation will dwarf any war refugee issues. They claim "invasion" now, but this one will be an actual invasion.
avadodin 11 hours ago [-]
I know civilization sounds appealing but have you considered giant dragonflies?
VorpalWay 10 hours ago [-]
From what I read recently (and I don't remember where it was), the current thinking is that it wasn't oxygen levels or temperatures, but the lack of predators that let dragonflies grow that big. A big dragonfly is much slower and an easier target. So unless you get rid of birds, you won't have giant dragonflies.
cucumber3732842 7 hours ago [-]
You need high oxygen content in the air though. Insect style circulatory systems aren't efficient enough to get oxygen to the cells without the air having a super high concentration of oxygen to begin with.
Basically like how when people can't breath good you put them on oxygen to keep them alive only getting oxygen into the blood is the bottleneck rather than into the body.
lukeify 12 hours ago [-]
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Cthulhu_ 8 hours ago [-]
Assume that there will be a mass extinction event somewhere in the next 1000 years - meteor, WW3, whatever. If you'd then play a timelapse of earth, you'd see it on fire, cooling down, oceans forming, greenery forming, continental drift, north/south poles icing over and clearing, snowball (?) earth a few times, then in a short blip the rise and fall of humanity, then uh. more of the same. Geological (and universal) time scales are mind blowing.
padjo 35 minutes ago [-]
It's called the Holocene extinction and it's happening right now.
xg15 8 hours ago [-]
Yeah, this is also why the "the climate has changed before and will always change" comments are so misleading - indeed it does, and currently, it's in a cold phase, so if we're seeing rapid warming right now, then something is seriously off.
nephihaha 8 hours ago [-]
It is worth pointing out that there is evidence of warming on Mars just now. I don't doubt anthropogenic warming is a thing, but it appears there is a solar factor too.
toss1 6 hours ago [-]
If this is some kind of attempt to excuse human massive carbon emissions by mis-attributing warming to a broader geological or astro-pysical phenomenon, it completely ignores the insane RATE of warming.
The rate of warming in the last century is orders of magnitude faster than any natural geological warming trend. It is the mother of all hockey-stick graphs, conveniently drawn for us by Randall Munroe [0]. Note: you will need too scroll a lot.
I've read that, and I wasn't attempting to say anything about human activity.
The intention was to draw attention to the grand scope of the earth's history, and the rare climate in which we reside.
Amorymeltzer 8 hours ago [-]
I hugely recommend reading Peter Brannen's The Story of CO2 Is the Story of Everything. I picked it up thinking it'd be a good book about climate change—it is—but it's so much more. It's an excellent journey through our planet's (bio)geochemistry, and really gives you a sense for the power and scope of CO2 over millions and billions of years. Snowball earth features prominently, and there are some really fascinating history and consequences of them.
perrygeo 4 hours ago [-]
Seconded. I learned a ton from it, as well as his previous book The Ends of the World on mass extinctions. His writing style is wonderful, he turns an academic subject into a page-turner.
The Story of CO2 taught me something I had never considered. It wasn't exactly that photosynthetic life started pumping out O2 and chilled the planet. Snowball earth happened way later. It was photosynthetic life that got buried in sediment and locked it away from aerobic respiration. The amount of carbon stored in the earth's crust is insane. Fossil fuels are just a minuscule fraction of that.
This has some implications for our current climate: If we want to use biology to sequester carbon (growing trees, algae, etc), it's only a temporary sink unless we lock it away for eons. Once it's eaten/burned, the CO2 is right back in the atmosphere. In short, we gotta physically put it back into the earth's crust if we want to draw down carbon.
The Lithos Carbon idea is interesting. The mine they show looks like they can just scrape it rather than needing to mine it with explosives. Unfortunately the site's blog has 1 post and it is 3.5 years old. Is it still a going concern?
chris_va 19 hours ago [-]
It's really the alkalinity (e.g. the Mg++ or Ca++), which silicate rocks often have (but technically not limited to silicates).
As an aside, we need to dissolve roughly one large mountain into the mix layer (top ~50m) of the ocean to have it fully take up atmospheric CO2. Without dissolving, the reaction is very slow (co2 in atmosphere => slightly lower pH rain => reaction with mostly passivated rock + erosion).
russearyus 17 hours ago [-]
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amelius 11 hours ago [-]
If only we could get the albedo to such value that we get a self-sustaining cycle of lower temperatures. Maybe if we turned that great pacific garbage patch into a great pacific mirror patch.
cousinbryce 21 minutes ago [-]
Disco Ball Earth
layer8 8 hours ago [-]
Enough bleach should do the trick. ;)
jtwaleson 15 hours ago [-]
Just as a thought experiment, what would be worse for humanity. Global warming or global cooling by the same amount of degrees C?
I'm in western Europe and really hope the AMOC will not collapse.
timschmidt 15 hours ago [-]
Global cooling could be worse. But the danger from either comes from the speed with which it happens, and inflexible sociopolitical structures, more than the absolute difference in temperature. Rapid change doesn't permit gradual adaptation like relocation to more habitable areas. The danger from the current global warming trend comes from it's incredible rapidity compared to historical trends.
Given time, humans and other animals will move toward the poles or toward the equator to find habitable zones. Put that on a rush schedule and everyone suffers.
CalRobert 10 hours ago [-]
How does growing crops work when it's dark 6 months a year?
lproven 9 hours ago [-]
> How does growing crops work when it's dark 6 months a year?
Have you noticed that all broadleaved trees and shrubs lose their leaves for half the year in temperate zones already?
Did you not wonder why that is?
They'll be fine. Annual crops are fine. Wildlife is fine if it's got somewhere to migrate to.
Tough for wildlife when there's nowhere to migrate to, though. But what's burning desert in summer might be just about tolerable hot tropics in winter.
The problem is that current tropical species can't handle the alternation of the seasons. You don't get seasons at the equator. Spring/summer/autumn/winter is a temperate-zones thing. Near the equator the sun rises and sets at the same time every day, and there are at best 2 seasons: the dry season, when it never rains, and the wet season, when it rains a lot all the time.
cucumber3732842 7 hours ago [-]
>How does growing crops work when it's dark 6 months a year?
Just fine. If the temperature would cooperate.
The land of the midnight sun actually has great yields for the few crops that tolerate the cool temperatures (low ground greens and vegetables basically, not staple grains or fruit). But because the season is so short temperature wise nobody really farms that stuff commercially up there.
arjunchint 14 hours ago [-]
there are no guarantees in life, can look up any random day and see a meteor streaking across the sky and realize that this is the end regardless of "sociopolitical structures".
All that matters is sociotechnological progress to be able to progress further enough to overcome these tests of existence.
timschmidt 14 hours ago [-]
> look up any random day and see a meteor streaking across the sky
That's happened rather more times in Earth's history than most folks are comfortable admitting. Tunguska would have leveled any major metropolitan city on the planet. I still think an impact is one of the more likely initiators of the Younger Dryas abrupt cooling and worldwide ~100M sealevel rise ~12,000 years ago. Conspicuously aligned with the oldest surviving traces of city living, agriculture, etc. It's increasingly accepted that a large portion of human history is 100M underwater on the continental shelves, estuaries, and other coastal areas where humans would have liked to live.
mjhay 9 hours ago [-]
The impact hypothesis for Younger Dryas isn’t really tenable. Among other things, the climate effects of a large bolide impact would be global, whereas Antarctica actually warmed during YD. This “Polar See-saw” pattern is easily explained by a northerly meltwater pulse hypothesis, but not a bolide.
vkou 13 hours ago [-]
Sea level rise was much faster before the cooling of the Younger Dryas.
It's possible the sea level rise could have initiated the cooling. But there is much disagreement as to what exactly initiated the de-glaciation which caused the sealevel rise.
lproven 9 hours ago [-]
> I'm in western Europe
Me too.
> and really hope the AMOC will not collapse.
It absolutely categorically will, probably in a decade or two.
However, as the rest of the planet rapidly warms, for a decade or so western Europe gets cooler and wetter. I only have 2 or 3 decades to live at best, so it's swings and roundabouts: some you lose, some you win.
SenHeng 10 hours ago [-]
There's an anime called Snowball Earth being aired right now.
This article is not about that.
layer8 8 hours ago [-]
You don’t say.
SenHeng 5 hours ago [-]
Not everyone reads TFA before coming in to the comments.
The title is ambiguous enough and anime is something that a lot of nerds enjoy.
layer8 2 hours ago [-]
I fail to see how one could conceivably think it’s about the anime, given the title. Nerds also know what “snowball earth” normally refers to.
metalman 9 hours ago [-]
Having followed every bit of info, data, and discussion(that I can find) on climate, geology, etc, since I was a child in the 1970's, I can point to the fact that earth climate science is ferociously complex, but that almost all of the variables are pushing towards a much warmer planet, and that there is NO big offset.
Like it or lump it, we have whatever passes for a global civilisation, where we are so intertwined that we cut special "deals" with the people we are bombing and bieng bombed by, for certain trade items, ie: gasses for chip production, "humantarian exemptions", etfuckingcetera, and so the real threat to
All That™, is ocean rise, as it can wipe out shipping fast under some realistic scenarios
, which if fact, are playing out there preliminary set points.
Short term (low single-digit decades): rapid sealevel rise. When (not "if") the Thwaites Glacier goes and the West Antartic Ice Sheet floats (not melts, just gets seawater underneath it) then we're looking at circa 5 metres, stabilising globally in about 12 days.
Goodbye every single coastal city, air or sea port, industrial area, power plant, transport infrastructure in the world.
Medium term (high single-digit decades): rapid global warming pushing the habitable zones to the poles and sub-polar regions. Note, critically, that means agriculture, as there are no established ecosystems to hunt/gather from at the poles.
We are heading for ~7º C by the end of the 21st century. Never mind 4º, double it.
Long term (millennia): another mass extinction event, much as the previous ones. We're 75-80% of the way through already, though.
Geological terms...
Hundreds of thousands of years: if humans go extinct, the planet will recover in 100K years or so, with plentiful but severely species-impoverished ecosystems.
Tens of millions of years: lots of new species, new rich ecosystems form.
Hundreds: if another sentient species evolves, it will have a hard time bootstrapping an technological civilisation, as we've extracted most of the the easy-to-access resources.
Earth spends most of its time in greenhouse phases.
"A "greenhouse Earth" is a period during which no continental glaciers exist anywhere on the planet... Earth has been in a greenhouse state for about 85% of its history.
"Earth is now in an icehouse state, and ice sheets are present in both poles simultaneously... Earth's current icehouse state is known as the Quaternary Ice Age and began approximately 2.58 million years ago... Earth is expected to continue to transition between glacial and interglacial periods until the cessation of the Quaternary Ice Age and will then enter another greenhouse state."
https://en.wikipedia.org/wiki/Greenhouse_and_icehouse_Earth
1: https://en.wikipedia.org/wiki/Geologic_temperature_record#/m...
https://www.weather.gov/ict/WBGT
https://www.psu.edu/news/research/story/humans-cant-endure-t...
UNIVERSITY PARK, Pa. — As climate change nudges the global temperature higher, there is rising interest in the maximum environmental conditions like heat and humidity to which humans can adapt. New Penn State research found that in humid climates, that temperature may be lower than previously thought.
It has been widely believed that a 35°C wet-bulb temperature (equal to 95°F at 100% humidity or 115°F at 50% humidity) was the maximum a human could endure before they could no longer adequately regulate their body temperature, which would potentially cause heat stroke or death over a prolonged exposure.
Wet-bulb temperature is read by a thermometer with a wet wick over its bulb and is affected by humidity and air movement. It represents a humid temperature at which the air is saturated and holds as much moisture as it can in the form of water vapor; a person’s sweat will not evaporate at that skin temperature.
But in their new study, the researchers found that the actual maximum wet-bulb temperature is lower — about 31°C wet-bulb or 87°F at 100% humidity — even for young, healthy subjects. The temperature for older populations, who are more vulnerable to heat, is likely even lower.
That's a problem at the Equator, but not at the higher latitudes.
Earth would have to experience > +35 to +50C for the poles to be uninhabitable due to heat.
Not reliably, not continually, and much less often when you dump enough energy into the atmosphere to disrupt major wind patterns.
British Columbia hitting 121°F/49.6°C at 50°N latitude would sort of suggest your generalization doesn't hold true anymore.
Here's a citation demonstrating that over the last 95 million years if you need one: https://www.pnas.org/doi/10.1073/pnas.2111332119
One more just for fun: https://journals.ametsoc.org/view/journals/clim/12/4/1520-04...
The mad rush to get there would likely extract a heavy toll.
Rain patterns and extreme weather events are the things to really worry about. Temperature changes alone can be mostly dealt with by planting different crops.
Climate refugee situation will dwarf any war refugee issues. They claim "invasion" now, but this one will be an actual invasion.
Basically like how when people can't breath good you put them on oxygen to keep them alive only getting oxygen into the blood is the bottleneck rather than into the body.
The rate of warming in the last century is orders of magnitude faster than any natural geological warming trend. It is the mother of all hockey-stick graphs, conveniently drawn for us by Randall Munroe [0]. Note: you will need too scroll a lot.
[0] https://xkcd.com/1732/
The intention was to draw attention to the grand scope of the earth's history, and the rare climate in which we reside.
The Story of CO2 taught me something I had never considered. It wasn't exactly that photosynthetic life started pumping out O2 and chilled the planet. Snowball earth happened way later. It was photosynthetic life that got buried in sediment and locked it away from aerobic respiration. The amount of carbon stored in the earth's crust is insane. Fossil fuels are just a minuscule fraction of that.
This has some implications for our current climate: If we want to use biology to sequester carbon (growing trees, algae, etc), it's only a temporary sink unless we lock it away for eons. Once it's eaten/burned, the CO2 is right back in the atmosphere. In short, we gotta physically put it back into the earth's crust if we want to draw down carbon.
silicate rocks basically traps co2 over millions of years and causes temperatures to fall
https://www.lithoscarbon.com/
https://en.wikipedia.org/wiki/Carbfix
https://co2crc.com.au/
https://sgeas.unimelb.edu.au/research/carbon-trap-lab
As an aside, we need to dissolve roughly one large mountain into the mix layer (top ~50m) of the ocean to have it fully take up atmospheric CO2. Without dissolving, the reaction is very slow (co2 in atmosphere => slightly lower pH rain => reaction with mostly passivated rock + erosion).
I'm in western Europe and really hope the AMOC will not collapse.
Given time, humans and other animals will move toward the poles or toward the equator to find habitable zones. Put that on a rush schedule and everyone suffers.
Have you noticed that all broadleaved trees and shrubs lose their leaves for half the year in temperate zones already?
Did you not wonder why that is?
They'll be fine. Annual crops are fine. Wildlife is fine if it's got somewhere to migrate to.
Tough for wildlife when there's nowhere to migrate to, though. But what's burning desert in summer might be just about tolerable hot tropics in winter.
The problem is that current tropical species can't handle the alternation of the seasons. You don't get seasons at the equator. Spring/summer/autumn/winter is a temperate-zones thing. Near the equator the sun rises and sets at the same time every day, and there are at best 2 seasons: the dry season, when it never rains, and the wet season, when it rains a lot all the time.
Just fine. If the temperature would cooperate.
The land of the midnight sun actually has great yields for the few crops that tolerate the cool temperatures (low ground greens and vegetables basically, not staple grains or fruit). But because the season is so short temperature wise nobody really farms that stuff commercially up there.
All that matters is sociotechnological progress to be able to progress further enough to overcome these tests of existence.
That's happened rather more times in Earth's history than most folks are comfortable admitting. Tunguska would have leveled any major metropolitan city on the planet. I still think an impact is one of the more likely initiators of the Younger Dryas abrupt cooling and worldwide ~100M sealevel rise ~12,000 years ago. Conspicuously aligned with the oldest surviving traces of city living, agriculture, etc. It's increasingly accepted that a large portion of human history is 100M underwater on the continental shelves, estuaries, and other coastal areas where humans would have liked to live.
It's possible the sea level rise could have initiated the cooling. But there is much disagreement as to what exactly initiated the de-glaciation which caused the sealevel rise.
Me too.
> and really hope the AMOC will not collapse.
It absolutely categorically will, probably in a decade or two.
However, as the rest of the planet rapidly warms, for a decade or so western Europe gets cooler and wetter. I only have 2 or 3 decades to live at best, so it's swings and roundabouts: some you lose, some you win.
This article is not about that.
The title is ambiguous enough and anime is something that a lot of nerds enjoy.
https://www.ospo.noaa.gov/products/ocean/sst/contour/
https://nsidc.org/sea-ice-today
https://climatereanalyzer.org/clim/seaice_daily/?nhsh=nh
Goodbye every single coastal city, air or sea port, industrial area, power plant, transport infrastructure in the world.
Medium term (high single-digit decades): rapid global warming pushing the habitable zones to the poles and sub-polar regions. Note, critically, that means agriculture, as there are no established ecosystems to hunt/gather from at the poles.
We are heading for ~7º C by the end of the 21st century. Never mind 4º, double it.
Long term (millennia): another mass extinction event, much as the previous ones. We're 75-80% of the way through already, though.
Geological terms...
Hundreds of thousands of years: if humans go extinct, the planet will recover in 100K years or so, with plentiful but severely species-impoverished ecosystems.
Tens of millions of years: lots of new species, new rich ecosystems form.
Hundreds: if another sentient species evolves, it will have a hard time bootstrapping an technological civilisation, as we've extracted most of the the easy-to-access resources.