logoalt Hacker News

Snowball Earth may hide a far stranger climate cycle than anyone expected

80 pointsby wglbyesterday at 10:18 PM22 commentsview on HN

Comments

chasiltoday at 3:18 AM

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

show 1 reply
wglbyesterday at 10:19 PM

Paper in Proceedings of the National Academy of Sciences: https://www.pnas.org/doi/10.1073/pnas.2525919123

dmixyesterday at 11:56 PM

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

show 2 replies
jtwalesontoday at 4:56 AM

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.

show 1 reply