My idea about the cause of the Younger Dryas

[repoman]

http://en.wikipedia.org/wiki/Younger_Dryas

I think that maybe a huge amount of glacial till (much of it silicates) was weathered very quickly after the glaciers melted and this drew down CO2 levels quickly and temp with it.

Is this plausible and is the evidence for or against it?

This may be dumb, but I am actually posting this thread before even looking at the CO2 levels around the time of the Younger Dryas. I will look in a few minutes.

 

[bilby]

http://en.wikipedia.org/wiki/Younger_Dryas

I think that maybe a huge amount of glacial till (much of it silicates) was weathered very quickly after the glaciers melted and this drew down CO2 levels quickly and temp with it.

Is this plausible and is the evidence for or against it?

This may be dumb, but I am actually posting this thread before even looking at the CO2 levels around the time of the Younger Dryas. I will look in a few minutes.

I believe the current 'best guess' for the Younger Dryas is melt-water run-off causing a drop in surface water density in the North Atlantic, and a consequent shutdown of the thermo-haline convection that drives the Gulf Stream. This hypothesis is a better fit than an atmospheric driven cooling, given that Greenland and Western Europe appear to have been disproportionately affected by the cooling at that time, in comparison to regions around the Pacific, for example.

There are other hypotheses out there; volcanism, solar activity or a meteorite impact have all been suggested, and not definitively ruled out; but the North Atlantic thermo-haline shut-down appears to be the best fit with the global pattern of temperature variation, insofar as we are able to measure it.

Of course there is also the possibility that more than one of these events may have combined to produce the sharp changes in temperature.

 

[repoman]

Yeah, that makes sense.

Since weathering is such a slow process, would the glacial cycles that have been going on the the past 2.5 million years be further amplified by the huge increase of surface area of rocks subject to chemical weathering that can lock up CO2?