We quantify the interannual-to-decadal variability of the heat content (mea
n temperature) of the world ocean from the surface through 3000-meter depth
for the period 1948 to 1998. The heat content of the world ocean increased
by similar to 2 X 10(23) joules between the mid-1950s and mid-1990s, repre
senting a volume mean warming of 0.06 degrees C. This corresponds to a warm
ing rate of 0.3 watt per meter squared (per unit area of faith's surface).
Substantial changes in heat content occurred in the 300- to 1000-meter laye
rs of each ocean and in depths greater than 1000 meters of the North Atlant
ic. The global volume mean temperature increase for the 0- to 300-meter lay
er was 0.31 degrees C, corresponding to an increase in heat content for thi
s Layer of similar to 10(23) joules between the mid-1950s and mid-1990s. Th
e Atlantic and Pacific Oceans have undergone a net warming since the 1950s
and the Indian Ocean has warmed since the mid-1960s, although the warming i
s not monotonic.