Interesting preprint by @atthenius et al 2024 on the teleconnection of Sahara Greening and ENSO (up to?) 6,000 years ago essopenarchive.org/doi/full/10…
"Thus, ENSO's sensitivity to Green Saharan changes in northern Africa reflects the importance of incorporating vegetation and land surface changes in studying past and future climates."

The same team also held an EGU or AGU talk this year about the Green #Sahara's teleconnection to the #Arctic also for the period 6ka and they said "We show that simulations incorporating the Green Sahara yield considerably higher Arctic warming relative to simulations without explicit prescriptions of vegetation changes. " meetingorganizer.copernicus.or…

If I had a wish, I'd want the team investigate the common era AD 1000ff, and include the #AMOC reconstruction by @rahmstorf et al 2015, and Nino3.4 by Cook et al 2008.
And incorporate the vegetation cover change due to population changes in the 1610-event and in the 1940-event when (CO2 concentration and CO2 growth dropped dramatically and) AMOC did a nosedive in what looks like a response to both changes in land use.
See my chart below and note that the 1940-event was also accompanied by a large drop in Asia's population growth I hadn't known of yet when I made the chart.

I'll post another chart tomorrow showing Cook's and Rahmstorf's time series and how well they are in sync (when AMOC data is moved 13 years into the future).

Both "discoveries" had me brood over the possible teleconnection between the two tipping elements AMOC and #Amazon rainforest the other way round than what is known as fact. To me it looks as if it works both ways: the closure of the forest canope in the 1610-event also slowed down AMOC to its then lowest speed ever. And again in the 1940-event.

Since Cook's Nino3.4 and AMOC evolve so similarly in AD, another bit from the ENSO preprint has to be mentioned. 6ka, ENSO was in a permanent La Nina state:
"precessional changes intensified the West African Monsoon (WAM), which further led to a “Green Sahara”, i.e. the expansion of shrub vegetation across northern Africa in place of the present-day Saharan Desert. Basin-wide multi-proxy evidence from the Pacific has indicated that the Middle Holocene was also characterized by a La Niña-like mean state with lower ENSO variability"

And this, lords & ladies, was something Matt England's team found in models 2022: a future AMOC slowdown causes a permanent LaNina agupubs.onlinelibrary.wiley.co…
And again in 2023 agupubs.onlinelibrary.wiley.co…

And we now need to know: what will be the climate impact on ENSO and AMOC when our tech civilisation crashes, empties all cities and all of Global North where people simply are too tech dependent to survive the crash. Also frees up today's tropical soy and palm tree plantations to be re-conquered by forests, since no one will "need" Nutella or biodiesel anymore.

Change in vegetation drives huge changes in atmospheric currents, water cycle, and regional climates. We owe it to crash survivors to inform them what they'll have to cope with in their region during the decades until the biome changes have fully materialised. I guess 60 years or so until New York, Rio, Tokyo look like a South American jungle with the ruins of skyscrapers piercing the forest canope.
And we owe them the info about what comes after.
That's why I propose official research in #RCPcollapse or #SSP0 .

But legraLeGra's team investigating AMOC, ENSO and vegetation build-up following population drops in the current era (#plague outbreaks as well? From memory 1348, 596, 1890) would be a great first start! Hopefully paving the way to a new full research body that can directly and positively influence how the rural survivors can prepare before, and re-group after the civilisation crash.
#PaleoClimate