Identification and analyses of Pliocene marine microfossils from 64 globally distributed stratigraphic sequences have been used to produce a middle Pliocene sea surface temperature reconstruction of the Earth.  This reconstruction shows little of no change from current conditions in low latitude regions and significant warming of the ocean surface at mid and higher latitudes of both hemispheres.  This pattern of warming is consistent with terrestrial records and suggests a combination of enhanced meridional ocean heat transport and enhanced greenhouse effects were responsible for the middle Pliocene warmth.