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?
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.
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.
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.
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.
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?
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.
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?
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).
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.
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.
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.
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.
> 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.
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.
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.
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."
https://en.wikipedia.org/wiki/Greenhouse_and_icehouse_Earth
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?
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.
1: https://en.wikipedia.org/wiki/Geologic_temperature_record#/m...
Hmm. I do like civilization. How about humans, would human life thrive?
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.
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.
Oh, yeah, like even if it's survivable for humanity in general, it's going to kill billions of humans.
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.
> 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.
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?
Certain investment firms purchased cold-weather ports which were iced in 8 months a year, 20 years ago, which now operate nearly year-round.
Sounds like a good long term investment. And maybe not that long term!
I know civilization sounds appealing but have you considered giant dragonflies?
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.
Paper in Proceedings of the National Academy of Sciences: https://www.pnas.org/doi/10.1073/pnas.2525919123
TIL about silicate weathering https://en.wikipedia.org/wiki/Carbonate%E2%80%93silicate_cyc...
silicate rocks basically traps co2 over millions of years and causes temperatures to fall
There are various companies/projects set up around that idea:
https://www.lithoscarbon.com/
https://en.wikipedia.org/wiki/Carbfix
https://co2crc.com.au/
https://sgeas.unimelb.edu.au/research/carbon-trap-lab
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?
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).
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.
There's an anime called Snowball Earth being aired right now.
This article is not about that.
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.
https://www.ospo.noaa.gov/products/ocean/sst/contour/
https://nsidc.org/sea-ice-today
https://climatereanalyzer.org/clim/seaice_daily/?nhsh=nh
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.
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.
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.
How does growing crops work when it's dark 6 months a year?
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.
> 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.
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.
Sea level rise was much faster before the cooling of the Younger Dryas.
You're right, and here's a graph: https://en.wikipedia.org/wiki/Past_sea_level#/media/File:Pos...
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.