Sunday, January 22, 2012

Trenberth Response to Today's Loeb et al Paper on Missing Energy

I asked Kevin Trenberth for his thoughts on today's Loeb et al paper in Nature Geosciences, since he and John Fasullo have been doing a lot of work on determining and identifying the missing energy. It's interesting:
"It seems to have its main point that our earlier paper was wrong. I will certainly disagree with that. In our earlier papers (refs 2,8 and 27) we pointed out that there were major discrepancies between the inventory of energy uptake in the climate system, mainly in the oceans, and the top-of-atmosphere observed changes. The period of "missing energy" was 2008-2009 which was a La Nina period and their Fig 2 shows indeed that there was a large input of energy into the climate system at that time. But 2008 was the coldest year this century and so where did the heat go?

We did not make a big deal about the uncertainties in the observations which are highlighted in this paper. But we were well aware of them. The main point of our paper was that yes, perhaps the observations are consistent within the error bars but if so, the error bars (uncertainties) are so large as to make the values useless. A key purpose of our paper was to challenge both the ocean heat content community and the CERES (atmospheric radiation) communities to do better. Both have responded and the situation has improved somewhat. The latest CERES data as reported here has corrected their data and found about 20% of the problem. In addition the OHC communities have improved their estimates and some of the problem has gone away from that standpoint too. But there remain some major problems. As they note on p 3: the correlation with two of the OHC data sets is only 0.05, and they choose to use the one that is correlated 0.46. Even that is not very good and is not significant for so few values.

Moreover, the uncertainties computed by Loeb et al for CERES appear to be wrong. They included the systematic error in the interannual error bar, so the real error bar on the change is less than shown and in fact it seems likely the agreement is not within the uncertainty.

So while their conclusions may be valid: yes there is no evidence of a discrepancy, given their uncertainties, and yes there is no "statistically significant" decline in OHC rates of change, but the uncertainties are so large that neither dataset is useful to know what is really going on, and that is the key point. The discrepancies among OHC data sets remain huge. We MUST do better. So the key point in their title is "within uncertainty". It should add: "but the uncertainty is too large."
The necessity and difficulty of combining all these datasets is a good reminder that all the people building sensors and launching satellites and transmitting data and slaving away at their computers all day long to make the data compatible, consistent, and usable are doing really important work. I hope their office has a window.


Oliver K. Manuel said...

David we had the Neon Alphabet Soup (Ne-A, Ne-B, Ne-C etc) in the 1980s, probably before your time.

Climategate exposed the tip of a dirty "little secret" that had grown out of sight in government funded science programs since at least December 25, 1975.

That holiday season the late Dr. D. D. Sabu and I devoted our vacation time to trying to find why experimental confirmation of a local supernova (our 1972 paper in Nature) was published in the last issue of Science's 1975 magazine as evidence of SHE (superheavy elements) in meteorite?

Although the new data in fact showed that the Sun itself made our elements, already in late 1975 the propaganda machine was so well funded that even Nobel Laureate Glenn T. Seaborg could not stop it.

Although promoters of SHE did finally admit their mistake in the 1980s, it was not until Nov 2009 that Climategate emails and documents revealed the reason why information on Earth's heat source was misrepresented in the first place.

Dano said...

A somewhat differently-constructed worldwide! conspiracy theory than we normally see from the Gish-galloping (& creepy little) spam bots.



Robert Murphy said...

Oliver, are you ever going to stop spamming websites with your Iron Sun crap? You post the same thing every time. This thread has nothing to do with your post.

david lewis said...

Hansen appears to be taking the position that the latest analysis of OHC that uses only ARGO data, von Shuckmann and Le Traon 2011, is an advance on the analyses of OHC that have gone before.

Trenberth seems to be saying in your quote that the latest analysis is just one more, and that the OHC community needs to pronounce something more emphatic about which one to take seriously.

Meanwhile, Hansen, taking the von Schuckmann and Le Traon analysis seriously, says "most" models need to be fixed. The models put the planetary energy imbalance at about 1 degree C whereas the latest ARGO assessment means its only .75 degree C at most.

He dismisses the idea that TOA observations are precise enough to measure the planetary energy imbalance as "prima facie preposterous". He republished Trenberth's original "missing energy" chart with one of his own right below it, only his chart showed no "missing energy".

Hansen's chart was based on a mythical model he made up where climate responded more quickly to forcings because less heat was mixed into the oceans, but he says he's got data, CFC tracers showing oceans mix less efficiently than believed, up his sleeve somewhere. He's working with ocean modellers to improve his model.

An implication of his reduced planetary energy imbalance figure and faster climate response function assumption is that more energy is being reflected back out into space by aerosols. He has upped his estimate of what the negative forcing caused by human emitted aerosols is to 1.6 w/m2.

It would be great to hear Trenberth comment on Hansen's assessment of the potential of TOA observation, on why he disagrees with Hansen about how seriously to regard the latest ARGO analyses, and as well, on the whole Hansenian song and dance.

david lewis said...

Trenberth cites three papers in this quote you've posted - but only the earliest i.e. the 2009 paper is consistent with what he's saying, i.e. the error bars are so great the measurements are useless.

Loeb cite the later 2010 Science "Perspectives" piece , the one with the chart showing there is some "missing energy". Trenberth's thought evolved over the three papers. He went from 2009 we don't have the ability to measure the planetary energy imbalance, but we should have this ability, to this 2011 paper where he asserts "we infer that the main sink of the missing energy is likely the deep ocean below 275 m depth". He's picking a set of measurements to accept, i.e. TOA satellite observations and modelled values of what's happening at the TOA, and asserting that the OHC people have missed a load of energy that has been going into the ocean.

This is quite different than his assertion that he was challenging both the ocean heat content and CERES communities.

Hank Roberts said...

Did Dr. T. say whether he's going to send a comment or followup to the journal about this paper?

David Appell said...

Hank, he didn't say, and I didn't ask.

(Sorry I didn't approve your comment earlier -- I didn't notice it. I only hold comments on posts that are older than 7 days old, and that's only to stop comment spam.)