Snowball Earth may hide a far stranger climate cycle than anyone expected (sciencex.com)
90 points by wglb 12 hours ago
chasil 7 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."
AlotOfReading 5 hours ago
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 4 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.
1: https://en.wikipedia.org/wiki/Geologic_temperature_record#/m...
reverius42 3 hours ago
wglb 12 hours ago
Paper in Proceedings of the National Academy of Sciences: https://www.pnas.org/doi/10.1073/pnas.2525919123
SenHeng an hour ago
There's an anime called Snowball Earth being aired right now.
This article is not about that.
amelius 2 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.
metalman 17 minutes 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.
https://www.ospo.noaa.gov/products/ocean/sst/contour/
dmix 11 hours ago
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
prawn 10 hours ago
There are various companies/projects set up around that idea:
fred_is_fred 8 hours ago
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 10 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).
jtwaleson 6 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 6 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 an hour ago
How does growing crops work when it's dark 6 months a year?
arjunchint 5 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.