  The extent of anthropogenic influence on the Earths climate warrants studies
of the ocean as a major player. The ocean circulation is important for
transporting properties like heat, carbon and nutrients. A supposed major
conduit is the Atlantic Meridional Overturning Circulation (AMOC).
Schematically, it transports heat from the equator to the poles near the
surface and carbon in the abyssal return. As the AMOC is a complex nonlinear
dynamical system, it is challenging to predict its potential to collapse from a
statistical viewpoint using a particular estimator of sea-surface temperature.
Whilst this might be robust mathematically, it lacks physical insight of the
drivers of the AMOC. As is argued below, physical processes will alter the
estimators, and thereby statistical analyses.
