Friday, June 19, 2009

ocean heat

GISS = NASA’s Goddard Institute for Space Studies

Have changes in ocean heat falsified the global warming hypothesis?

This article argues that ocean heat provides a good correlation for the anthropogenic global warming (AGW) hypothesis and that since ocean heat has declined in the past 6 years that we ought to take another hard look at that hypothesis


Mark Miller said...

Good pick, Bill. I can't say I followed it 100%, but assuming everything about the paper was accurate the conclusions are pretty damning. I particularly liked this part:

Hidden Heat. A few explanations have been proposed for the change in ocean heat. One popular suggestion is that there is “hidden” or “unrealized” heat in the climate system. This heat is being “masked” by the current cooling and will “return with a vengeance” once the cooling abates.

This explanation reveals a fundamental ignorance of thermodynamics and it is disappointing to see scientists suggest it.

Heck I'd say it violates the principle of conservation of energy, which any high school science student should be able to pick up on.

This explanation of "hidden heat" came about to account for the fact that global average temperature has either been stable or dropping for the last 10 years, even though CO2 concentration has continued to go up. This contradicted the main theme AGW adherents had been promoting which is that rising CO2 results in higher global temperatures. So they said the heat had to be "hidden" for the time being, but was still building up energy, which would eventually be released "with a vengeance"...

I was hearing this explanation a few years ago that CO2 buildup was causing the oceans to warm. The problem with this is that it takes a LOOOONG time for ocean water to change temperature, as I understand it, on the order of a hundred years or more (of course depth and current flow have something to do with it as well). This gets to what DiPuccio talks about with heat vs. temperature, since heat takes mass and specific heat (rate of heating required to raise temperature by a certain temperature interval) into account. What I've heard about the oceans is they have what is called in climatology a "memory" of temperature. The ocean warmth that was seen by scientists 10+ years ago was probably the result of external warming (added energy to the system) that began near the beginning of the 20th century, or perhaps farther back than that.

But like DiPuccio said about the media and public policy, "Never mind the science. Push forward!" The Obama Admin. just recently released their report on climate change, and just in time, too. His cap and trade legislation is coming up for consideration by congress soon. The author of the blog post I linked to has also done a series of posts on the Obama Admin. (GCCI) report. The blog is Climate Skeptic.

Tony Forster said...

The graph you show only covers the period 2003-2008.
Over the period 1955-2007, there has been a fairly consistent upward trend in sea surface temperature and ocean heat content. This is shown for example at
There is considerable noise on the plot and the reduction over the past 5 years is consistent with that noise

Bill Kerr said...

I agree tony that the longer term trend is more important

Since your link goes to an earlier (2007) blog on the same site then this site is providing the broader overview (even though I didn't)

By my reading the article was more critique of an alarmist prediction by Hansen et al, not an outright denial

Mark Miller said...


I think you're misreading the graph you referred to. If you take a look at it again you'll see that the Y axis goes from -0.4 degrees C to +0.4 degrees C. The zero for the graph is in the middle. So what you see for the red line plot is from 1955-1979 the combined land and sea surface temperature (the SST data) is falling, but at a decreasing rate. Thereafter, from 1980 onward, the temperature in this data set increased fairly consistently.

If you look at the web page for the SST data you'll see this more clearly. In the upper right-hand corner they show 3 graphs of temperature increases and decreases from 1850 to 2005. During most of that time the combined temperatures were decreasing. The large rise in the combined temperature began in 1980.

If you look at just the "upper ocean" plot (the OHC data), it does not show a consistent upward trend, but rather oscillation. From 1955-1967 temperature increases. From 1967 to 1972 it decreases. From 1972 to 1980 it increases. From 1980 to 1990 it decreases. And then from 1990 to 2002 it increases.

Tony Forster said...

Mark "The zero for the graph is in the middle."

Yes, this is because they chose to normalise to the 1961-1990 mean, it has no significance beyond that.

Likewise the SST data are normalised to around 1980, the base year is arbitary.

"graphs of temperature increases and decreases"

If you are saying that the graphs are of annual temperature change then I think you are misinterpreting them, they are of annual temperature compared with an arbitary base year.

If you are referring to short term fluctuations within a long term trend then I think that you should look at the longer term trent with data which is so noisy.