The Oceans Aren't Heating !!! (Quite so fast ....)

Deniers Water Down Ocean Heating Trends

Have a look at the graph at left and ask yourself: does this indicate warming or cooling in the earth’s ocean?

Or check out this graph:

Ocean Heat Skeptic 1

If you said that these images appear to indicate an alarming warming trend, give your head a shake, because the people posting and commenting on these graphs are arguing exactly the opposite.

The first graph, which came originally from an excellent peer-reviewed study in the Journal of Geophysical Researc Letters (Levitus et al: Global Ocean Heat Content), was posted by the climate quibbler Roger A. Pielke Sr. in a post that pronounced this all good news - that climate has, in fact, stopped changing. Pielke says:

“The new Levitus et al. 2009 paper, while not discussing this issue, further confirms that global warming, using upper ocean heat content as the metric,  has stopped, at least for now.”

And thank goodness for that.

The second image, also using data from Levitus and adding the volcano data at the bottom, came from a post (Does Ocean Cooling Disprove Global Warming) by John Cook on Skeptical Science. Cook took Pielke’s position one step further, carving out the last four years of data to show an actual decline in temperature. It makes you want to go put on a jacket. (Ed. This para was based on an incorrect reading of the Cook post, which goes on to debunk the cooling ocean analysis.)

In yet another interpretation of the first graph, weatherman Anthony WattsUpWithThat, points to an Anomalous Spike In Ocean Heat Content between 2002 and 2003, coincidentally a point at which researchers began to get access to a much more reliable data set thanks to the introduction of new instruments. Watts opines:

“It thus looks to me like there may be an error in how the different data sets are stitched together”

He cleverly withholds comment on the steadily rising trend recorded between 1955 and 2002, notwithstanding the big jump that followed.

The gathering attack on ocean heat content data can, perhaps, be explained because ocean temperature is such a good metric for our changing climate. As Joel Upchurch says on Physics Forums:

“The basic argument is that very little of the earth’s heat is stored in the atmosphere and that the heat stored in the first 2.5 meters of the ocean is equivalent to the whole atmosphere. Therefore ocean heat storage is a more reliable tool to measure the radiative imbalances in our climate system than surface temperature changes.”

So, in the face of an increasingly accurate and compelling metric, we get what Roger Pielke describes as a “somewhat nuanced” reinterpretation.

If you want nuance, you should read the whole of the Levitus paper linked above. Or Google “RealClimate” and “ocean heat content” - they’ve canvased this issue nicely a couple of times.

If you want, instead, to close your eyes to the trend and cling desperately to three or four years of La Nina-driven stasis, then, by all means, buy into the bullshit being peddled by Pielke and Watts.



I think you’re misread my Skeptical Science article ( which was written as a rebuttal of Pielke’s position. Basically, I make two points. Firstly, ocean heat as seen in my graph shows much short term variation so a few years of cooling proves nothing regarding the long term trend.

Secondly, one cannot even conclude that the ocean has been cooling in the last few years. Levitus’ data shows a slight warming trend. And independent reconstructions from ocean heat based on satellite gravity measurements also show a warming trend. So my answer to the question “Does ocean cooling disprove global warming?” is no, it does not.

Hi John, Per the note above: yes I DID misread your piece, which for those who show more patience and attention than I did yesterday puts the issue nicely into context. Thanks you, and again: humblest apologies. r

okay - but if 6 years of better data is inconclusive, Is 40 years of lesser quality data really much to look at? Isn’t it fair to say we have a long way to go before we can speak much about Ocean temperature?

Global warming is such a farce. 90% of meteorologist don’t believe it, and the evidence of man made global warming is unfounded. Man made carbon output makes up less than 1/4 of 1% of the earths atmosphere. Get a clue on global warming.

In the main essay, Richard Littlemore wrote,

“The second image, also using data from Levitus and adding the volcano data at the bottom, came from a post (Does Ocean Cooling Disprove Global Warming) by John Cook on Skeptical Science. Cook took Pielke’s position one step further, carving out the last four years of data to show an actual decline in temperature. It makes you want to go put on a jacket.”

Richard, I believe you MISREAD John Cook’s essay.

John Cook is one of the good guys. The central conceit of his website is that science is by nature skeptical, but if the climate skeptics redirected just a little of the skepticism that they have towards mainstream science at their own arguments they would realize just how strong the mainstream position is. And time and time again, John Cook’s Skeptical Science tears the positions of the skeptics apart piece-by-piece after stating them. A very useful resource.

In fact you can see a hyperlinked list of the fifty-six big skeptical arguments he demolishes here:

This particular essay that you refer to may have come in quite handy when one “skeptic” who was debating me raised the “ocean heat content has been dropping for six years” argument over here:

RESULT: the buoys have found a slight ocean cooling in the six years they have been deployed. The biggest problem with the Argos sensor buoy findings is the readings fly in the face of major climate change computer models.” – TrustbutVerify

I thought the “skeptic” TrustbutVerify was arguing on the basis of the Willis paper “Recent Cooling in the Upper Ocean” (2006) covering the period for 2003-5 that showed ocean cooling (where Willis et al later concluded in 2007 that the ARGO floats from a particular manufacturer had malfunctioned and the “cooling trend” he had “observed” wasn’t real), not the “Cooling of the global ocean since 2003 (Loehles 2009).” No doubt the latter is what TrustbutVerify had in mind. But for some reason he tired of debate and never pulled out that ace. However, if he had, I could have pointed out that there is at least one study that shows a slight warming for 2003-2008 (the period the Loehles paper is actually covering) as mentioned by Cook here:

“Willis 2008 shows a cooling trend since 2004, while Leuliette shows a warming trend. The primary difference between the two is found early in the Argo record, when there were fewer Argo buoys deployed. Leuliette 2009 suggests the discrepancy between the two seems to be due to poor sampling and differences in how the data was handled. But which dataset is more accurate?”

… who then later states in his next to last paragraph from the piece that you are referring to:

“In climate discussions, the most common error is focusing on a single piece of the puzzle while ignoring the big picture. The ocean cooling meme commits this error twofold. Firstly, it scrutinises 6 years worth of data while ignoring the last 40 years of ocean warming. Secondly, it hangs its hat on one particular reconstruction that shows cooling, while other results and independent analyses indicate slight warming.”

The oceans are showing the effects of burning so much fossil fuels so fast. The temperature is just one measurement, and with ice melting into the oceans, and ocean currents distributing cold water to the surface, there are bound to be some anomalies. Deniers will jump on those anomalies to support their misguided opinions [as handed to them by the oilmen].

Ocean rise, as in sea surface elevation, is an indicator of warming too, and there is no doubt that it is rising.

Check out NASA’s website:
“Climate Change: Eyes on the Earth”

Another oceanic indicator is acidification, and in that there is no doubt [and no denials either!] that the oceans are becoming more acidic due to the carbon added from burning fossil fuels.
“Sea Sick” [Alanna Mitchell] is a book that leaves no doubt as to the urgent need to reduce carbon emissions.

It seems clear that upper ocean heat content rose for a long time prior to 2003. I am unaware of any serious argument to the contrary.

But the graph shows a huge uptick in upper ocean heat content in 2002 which almost certainly did not happen. It is the result of splicing the Argo data together with older upper ocean observations. Aside from this splicing artifact, there is no other evidence of a sudden spike in 2002.

Six years of no heating is not a sufficient basis for drawing conclusions.

But this much is certain: the climate models on which the whole AGW movement is based absolutely require that the oceans continue to absorb heat from the atmosphere as the planet realizes the so-called “committed” warming that existing greenhouse gas levels will ultimately cause.

If, over an extended time period (say another six years) the oceans do not resume their warming, existing climate models (and estimates of climate sensitivity) will be proved false. Either calculations of the earths radiative balance will have been proved wrong, or something even more interesting (and presently absent from the models) will have been discovered.

Upper ocean heating therefore deserves the attention it is getting.

If you are confident that the models are correct, then you can confidently predict that significant upper ocean warming will be observed from 2009 to 2015. Show those deniers how foolish they are by trusting in the models, using them to make a falsifiable prediction, and watching it come true.

If you think that the models are wrong, but want to argue that they are right in the hope of advancing your agenda before they are proved wrong, you should manufacture a bad splice of the Argo data with other data sets for a journal. Then post it on various blogs without noting that there are actually two separate data sets which are joined together by a nearly vertical line.

I find touching your absolute conviction that the climate scientists who prepared the original graphs are stone stupid and wouldn’t have noticed an unusual temperature rise coinciding with a change in technology. It’s good that we have clever bloggers with no real science expertise at all to “correct” these clumsy experts.