qThe deep ocean 100 Myr ago was filled with warm saline deep
water formed in
the tropics or subtropics, rather than with cold water from high latitudes.
qA strong flow of warm deep water
from the tropics to the poles
could have
contributed to the poleward heat flux needed to warm the poles.
qAlso, the warm salty deep water could have caused faster
overturning of the
deep ocean and greater poleward heat transport.