Andrew Revkin at the NYT writes,
"The study finds that the rise in ocean heat (and temperature) in recent decades is far faster than anything seen earlier in the Holocene, the period since the end of the last ice age. But the researchers say that this rise is from a relatively cool baseline. Between 10,000 and 8,000 years ago, at depths between 500 and 1,000 meters, the Pacific Ocean was some 2 degrees Celsius (3.6 degrees Fahrenheit) warmer than today for many centuries.""Warmer than today for many centuries" is an understatement, since the paper shows [Fig 4a below] that the Pacific Ocean from 0-700 meter depth heat content was greater than the latter 20th century for at least ~8,000 years or 80 centuries. For the intermediate depths from 600-900 meters, the reconstructed temperatures [Fig 2d] were higher than the end of the 20th century for about 95% of the past 10,000 years. Figure 4a also shows the only period with less Pacific Ocean heat content than the latter 20th century was during the "relatively cool baseline" during part of the Little Ice Age 1600-1800 AD.
Furthermore, the finding "that the rise in ocean heat (and temperature) in recent decades is far faster than anything seen earlier in the Holocene" spun & hyped by Revkin, Michael Mann, and the media appears to be inconclusive according to the author's statements recorded on video:
Comment from Chris Y at NYT:
Andy Revkin writes- "The study finds that the rise in ocean heat (and temperature) in recent decades is far faster than anything seen earlier in the Holocene, ..."
Actually, that is impossible to conclude from the data in the paper.
Keith DeHavelle transcribed a critical bit from the video and posted it at WUWT.
“(at 4:00 in the video)-
BRAD: We have fossils that have been bioturbated … we have pretty high accumulation rates, but we don’t have annual resolution .. You could say that we probably have century-scale resolution at best… It’s possible that the sediments just didn’t record similar warmings in the past.”
YAIR: The deep ocean tends to average and smooth the record … I think it’s fair to say that it’s unlikely that very rapid changes on the order of, let’s say, years or even decades … would show up in the record.”Chris y notes that this statement by the authors "eviscerates any claim of an unprecedented rate of ocean warming in the last 50 years. It is the same shambolic Marcott incident all over again."
Also, the paper uses data for the modern period from Levitus et al, which finds the world oceans have warmed only 0.09°C over the 55 year period from 1955-2010. An ocean that is 0.09C warmer can only warm the atmosphere by an additional 0.09C.
Pacific Ocean Heat Content During the Past 10,000 Years
Yair Rosenthal, Braddock K. Linsley, Delia W. Oppo
Observed increases in ocean heat content (OHC) and temperature are robust indicators of global warming during the past several decades. We used high-resolution proxy records from sediment cores to extend these observations in the Pacific 10,000 years beyond the instrumental record. We show that water masses linked to North Pacific and Antarctic intermediate waters were warmer by 2.1 ± 0.4°C and 1.5 ± 0.4°C, respectively, during the middle Holocene Thermal Maximum than over the past century. Both water masses were ~0.9°C warmer during the Medieval Warm period than during the Little Ice Age and ~0.65° warmer than in recent decades. Although documented changes in global surface temperatures during the Holocene and Common era are relatively small, the concomitant changes in OHC are large.
more hype on the recent rate of riseReplyDelete
More incredible hype as usual from Bryan Walsh @ Time MagReplyDelete
"Also, the paper uses data for the modern period from Levitus et al, which finds the world oceans have warmed only 0.09°C over the 55 year period from 1955-2010. An ocean that is 0.09C warmer can only warm the atmosphere by an additional 0.09C."ReplyDelete
And only if the water is in contact with air that is colder than the water. Deep ocean water that is near freezing doesn't heat very much atmosphere.
yes heat only flows from hot to coldDelete
The very last paragraph of the paper states that the recent warmingReplyDelete
"In these estimates we also i 230 nclude the errors associated with
231 our IWT estimates. We compare these rates with the average rate estimated for the 1955-2010 period for the Pacific Ocean. Using the total temperature change in each interval we calculate the change in OHC for each time interval and the rate of change in Joules per century. The estimates in Table S3, albeit with large uncertainties, suggest that the modern rate of Pacific OHC change is significantly higher than the absolute rates reconstructed for the past."
"suggest" is a clever way of glossing over the fact that this involves the problems of joining an instrumental dataset with much higher resolution to a proxy dataset, which the authors admit in the interview above has only centennial or less resolution. And the other issues as outlined by McIntyreDelete
shreds the claim that recent warming is unprecedented or unusual
McIntyre eviscerates claim that rate of recent warming is fastest in 10000 yearsReplyDelete
Dale R. McIntyre, PhDBartlesville, OklahomaReplyDelete
For the last five years, Pat Michaels of World Climate Report, Steve McIntyre at Climate Audit and Craig Idso's CO2 Science web site have been listing a plethora of solid studies in mainstream scientific journals which say the same thing as Rosenthal's study: that the Medieval Warm Period was global in extent, and warmer than the present, and thus the present warming episode is by no means unprecedented.
For having the temerity to cite mainstream scientific studies which contradicted the Prophets of Doom, Michaels, McIntyre and Idso have been pilloried as "deniers", "fossil fuel shills" and even "climate criminals".
And those of us who dared mention these studies here on Dot Earth have been subjected to a flood of scorn and calumny from CAGW True Believer Trolls with cutesy-poo noms-de-blog.
To reinforce the message of Rosenthal with only a few examples, consider:
Huang, S., et al, Geophys. Res. Letts,1997 24:1947-1950
Bhattacharyya, A., et al., Current Science 93:983-987, 2007
Scapozza, C., et al., Permafrost and Periglacial Processes, 2010, 21:90-96
Chiune, I., et al, Nature, 2004, 432:289-290
Barron, J.A., and Bukry, D., Marine Micropaleontology, 2007, 62:115-139
Ge, Q.S., et al, Geophys Res. Letts, 2010, 37:10.1029/2009GL041281.
Mikami, T., Weather, 2008, 63: 190-193
Sepulveda, J., et al, Quaternary Research, vol. 72: 400-409
from the 11/2/13 SEPP newsletter:ReplyDelete
Ocean Heat: A new paper claims to trace the Pacific Ocean heat content over the past 10,000 years. Using high-resolution proxy records from sediment cores, the paper stated "that water masses linked to North Pacific and Antarctic intermediate waters were warmer by 2.1 ± 0.4°C and 1.5 ± 0.4°C, respectively, during the middle Holocene Thermal Maximum than over the past century. Both water masses were ~0.9°C warmer during the Medieval Warm period than during the Little Ice Age and ~0.65° warmer than in recent decades." This is more evidence that Mr. Mann's hockey-stick was wrong; based on reports he is unhappy with the paper.
The paper was published in Science magazine, which has long had an editorial policy of not publishing papers that challenge the orthodoxy. Has the editorial policy of Science changed? Or is this an effort to buttress the claims that global warming projected in the climate models is hiding in the deep ocean. If it is the former, then it has been long needed. If it is the latter, then it has major problems.
As any diver knows, sunlight can penetrate deep into the ocean, up to 200 meters (656 feet) or more. So the cause of the past warming could be greater sunlight - such as a changing intensity or less cloudiness. However, the energy from atmospheric greenhouse gases is in the infrared region that does not penetrate much beyond 10 microns (less than 0.001 of an inch). So a significant increase in the greenhouse effect would cause a warming of the sea surface, which is not being observed. See links under Changing Climate and
Werner Brozek says:ReplyDelete
November 13, 2013 at 9:12 am
We have all of this talk about huge numbers of Hiroshima bombs and about all of the 10^22 Joules the oceans are taking up. But when converting to degrees C, there seems to be almost nothing left as was pointed out in this article. I will illustrate the facts in another way.
I will use Figure 5 and assume it is true.
According to this diagram, the total heat increase is about 25 x 10^22 J over about 55 years.
The total mass of the ocean above 2000 m is 48% of the total mass of the ocean.
The total mass of the ocean is 1.37 x 10^21 kg.
The specific heat capacity of ocean water is 4000 J/kgK.
Applying H = mct, I get a change in t of
25 x 10^22 J/(0.48 x 1.37 x 10^21 kg x 4000 J/kgK) = 0.1 K. Is that correct? If so, it would take over 100 years for the top 2000 m to go up by 0.2 C. Is that supposed to be a problem for us?
Vince Causey says:
November 14, 2013 at 12:41 pm
“Applying H = mct, I get a change in t of
25 x 10^22 J/(0.48 x 1.37 x 10^21 kg x 4000 J/kgK) = 0.1 K. Is that correct? If so, it would take over 100 years for the top 2000 m to go up by 0.2 C. Is that supposed to be a problem for us?”
I doubt it. This is the second law of thermodynamics at work – the entropy is increasing. Useful heat is being degraded into a more diffuse, low grade form.
It’s like taking a red hot poker and dropping it in a bath of cold water. The heat of the original red hot poker can be used to do some work, but once the heat is transferred to the bath, the temperature becomes that of the bath, whose temperature has risen by only a tiny amount.
The important point is that the heat, once diffused to a lower temperature, can never result in a subsequent rise in temperature, which would be contrary to the first law. Therefore, any heat, once sequestered by the oceans, can never reverse its thermodynamic pathway, and reheat the atmosphere to the temperatures that caused it to be absorbed in the first place.
It is an admission that the problem (if it ever existed), is being solved by nature once and for all.