>THE GLOBAL OCEAN HEAT CONTENT ROSE APPROXIMATELY 16*10^22 JOULES FROM 1969 to 2008
The units used to express Ocean Heat Content (OHC) are 10^22 Joules. Figure 1 from Levitus et al (2009) “Global Ocean Heat Content 1955–2008 In Light Of Recently Revealed Instrumentation Problems” follows. As illustrated, Ocean Heat Content of the upper 700 meters of the global oceans, using the linear trend as reference, rose approximately 16*10^22 Joules from 1969 to 2008, the period Levitus et al elected to use for linear trends. Link to Levitus et al (2009):
Levitus et al (2009) Figure 1
Unfortunately, most people cannot put that rise in Ocean Heat Content into perspective; that is, into familiar terms. Also, the number 16*10^22 Joules is simply too large to comprehend. An AGW proponent might write, “Since 1969, an additional 16*10^22 Joules of heat is being stored in the oceans.” The number is so large it sounds scary. Maybe that’s why it’s used.
BUT WHAT WAS THE TEMPERATURE RISE?
According to the supplemental material furnished with Levitus et al (2009), the temperature of the Global Oceans (0-700 meters) rose about 0.17 deg C from 1969 to 2008. Refer to Table T1 from Levitus et al (2009).
Levitus et al (2009) Table T1
This equals a trend of approximately 0.042 Deg C/Decade or less than a half degree per century for the upper 700 meters.
ARE THERE ANY REFERENCES FOR GREATER DEPTHS?
The Abstract of an earlier Levitus et al paper, one from 2005, “The Warming Of The World Ocean: 1955 to 2003” states, “During 1955–1998 world ocean heat content (0–3000 m) increased 14.5 × 10^22 J corresponding to a mean temperature increase of 0.037°C at a rate of 0.20 Wm−2 (per unit area of Earth’s total surface area).”
0.037 Deg C from 1955 to 1998 equals a linear trend of less than 0.009 deg C/ Decade. The rise doesn’t sound catastrophic in those terms.
THE IMPACTS OF NATURAL VARIABLES
There has been a recent push to use Ocean Heat Content as a measure of anthropogenic global warming. Unfortunately for AGW proponents, there is little evidence that anthropogenic greenhouse gases have an effect on Ocean Heat Content.
As illustrated and discussed in the following posts, natural climate variations are the dominant causes of the rises in Global Ocean Heat Content. One simply needs to break the global OHC data down into logical subsets to witness these effects.
ENSO Dominates NODC Ocean Heat Content (0-700 Meters) Data
North Atlantic Ocean Heat Content (0-700 Meters) Is Governed By Natural Variables
North Pacific Ocean Heat Content Shift In The Late 1980s