Artico verso l'abisso... eppure lo dicevamo che...

[elz]

Nessuno che dice nulla in merito a questa recente pubblicazione?

Ma che cosa stai cercando di dire? Che questo accadrà nel prossimo futuro? Perchè gli autori di quello studio la pensano ben diversamente, Andrè Berger che è un autorità nella paleoclimatologia ha a lungo sostenuto che questo interglaciale è destinato a durare a lungo ( almeno altri 50000 anni) se la co2 rimane sopra i 300 ppm e la soglia di cui parlano richiede ben più dei ghiacci artici ai massimi degli ultimi 7 anni.

Ad es. questa review di cui è il primo autore:
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These results show consistently, that a glacial inception is unlikely to happen within the next approximate 50 ka (when the next strong drop in Northern Hemisphere summer insolation occurs) if either atmospheric CO2 concentration remains above 300 ppm or cumulative carbon emissions exceed 1000 Pg C.

Only for an atmospheric CO2 content below the preindustrial level may a glaciation occur within the next 10 ka. This can be used to explain why glacial inception occurred during MIS 19c under astronomical configuration rather similar to the present one but at lower CO2 concentration(~240 ppm). Given the continued anthropogenic CO2 emissions, glacial inception is very unlikely to occur in the next 50 ka, because the timescale for CO2 and temperature reduction toward unperturbed values in the absence of active removal is very long, and only weak precessional forcing occurs in the next two precessional cycles.


e sull'incipit glaciale:

Important changes emanate from the high northern latitudes, where initial ice growth, vegetation shifts and albedo feedback are accompanied by dynamical changes in the ocean and atmosphere.

During the most recent and best studied glacial inception (from MIS 5e to MIS 5d), the early increase in sea ice export from the Arctic weakens and constricts the subpolar gyre circulation in the northwest Atlantic, enhancing northward penetration of warm, saline subtropical waters toward the northeast Atlantic and into the Nordic Seas . This in turn enhances convection and deepwater production in those seas and provides a negative feedback on sea ice production that contributes to a progressive millennial-scale oceanographic oscillation as insolation declines .

The intermittent, yet persistent, production of deepwater maintains an overturning circulation throughout the glacial inception that contributes to extended warmth in the North Atlantic. This warmth persists despite, and may even enhance, ice sheet growth on surrounding continents.

Variability in the extent of southern deep waters occurs at the same time , along with surface cooling and changes in the winds and sea ice around Antarctica .Northern ice sheet growth in this configuration appears to proceed rapidly, reaching the sea in the form of tidewater glaciers relatively early . The ocean-cryosphere interaction of icebergs and meltwater then influences deep convection and the overturning circulation , initiating the bipolar seesaw of millennial-scale temperature changes that characterizes glaciations .

A threshold for this response to initial ice growth is estimated to be 30–50 m of sea level equivalent and may be used to define the end of the peak interglacial. By this time, ice growth is sufficient and accompanied by reduced GHG concentrations and increased planetary albedo so that, despite subsequent increases in northern summer insolation, a return to full interglacial conditions is prevented, and glaciation generally proceeds progressively with only interspersed interstadial intervals until the conditions are eventually met for the next termination, as described earlier.