https://www.science.org/doi/10.1126/sciadv.adz2555
"Ocean circulation changes rather than global warming drove temperature trends across the Miocene Climatic Optimum" by Wubben et al 2026,
They solve the riddle how the middle Miocene Global Mean Temperature could have been so much warmer at only 400 to 600 CO2 ppm. So much warmer, that is Global Mean sea surface temperature 7 to 8°C warmer than today.
It's the ocean circulations. They were vastly different 15 million years ago because the land-ocean distribution was vastly different in locations where this really matters. And thus, heat transport was vastly different too.
Low latitude sea surface temperature proxies only record a warming by 2.5°C, uncertainty ±1.5.
Near Florida and on the west Atlantic coast 200km North of Cape Hatteras, sea surface was even 1 to 4°C cooler. That's the effect of a, then still open Panama-connection to the Pacific, I guess.
While Tasmania's and Europe's North Atlantic's sea surface proxies recorded 16 to 20°C hotter water than today.
Which means to my un-learned mind that AMOC existed but totally without the wind-driven Gulfstream?
And East Antarctica was ice-free which rendered Tasmania's waters a boiling kettle?
I hope I come across a Conversation piece or similar explaining a bit more.
#PaleoClimate #Miocene #MCO #OceanHeat #ClimateChange #ClimateSensitivity
anlomedad
npub1l5…hqwsw
2026-10-12 17:35:21 UTC
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npub1l5jvx9pac7nkef83x85eagftsr82flnqpltdpn43hrlpma7fj0hsvhqwswSeen on
wss://relay.momostr.pinkPublished at
2026-10-12 17:35:21 UTCEvent JSON
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"content": "https://www.science.org/doi/10.1126/sciadv.adz2555\n\"Ocean circulation changes rather than global warming drove temperature trends across the Miocene Climatic Optimum\" by Wubben et al 2026,\nThey solve the riddle how the middle Miocene Global Mean Temperature could have been so much warmer at only 400 to 600 CO2 ppm. So much warmer, that is Global Mean sea surface temperature 7 to 8°C warmer than today. \n\nIt's the ocean circulations. They were vastly different 15 million years ago because the land-ocean distribution was vastly different in locations where this really matters. And thus, heat transport was vastly different too. \nLow latitude sea surface temperature proxies only record a warming by 2.5°C, uncertainty ±1.5. \n\nNear Florida and on the west Atlantic coast 200km North of Cape Hatteras, sea surface was even 1 to 4°C cooler. That's the effect of a, then still open Panama-connection to the Pacific, I guess. \nWhile Tasmania's and Europe's North Atlantic's sea surface proxies recorded 16 to 20°C hotter water than today. \nWhich means to my un-learned mind that AMOC existed but totally without the wind-driven Gulfstream?\nAnd East Antarctica was ice-free which rendered Tasmania's waters a boiling kettle? \nI hope I come across a Conversation piece or similar explaining a bit more.\n\n#PaleoClimate #Miocene #MCO #OceanHeat #ClimateChange #ClimateSensitivity",
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