He was the first to suggest that ice ages were controlled by astronomical forces in his 1842 book Revolutions of the Sea.
Because of this, Adhemar reasoned that because the southern hemisphere had more hours of darkness in winter, it must be cooling, and attributed the Antarctic ice sheet to this.
One immediate objection to the theory was that the total insolation during a year does not vary at all during the precessional cycle, only its seasonal distribution.
Adhemar predicted the Antarctic ice sheet and theorised about its thickness by comparing the depths of the Arctic and circum-Antarctic oceans.
Finding the Antarctic oceans deeper (the measurements he used may not have been fully representative) and attributing this to the gravitational attraction of the Antarctic ice sheet, he postulated a truly enormous ice sheet approximately 90 km thick.