Update #3: PM September 8 2010 – Reponse to two further comments on th Skeptical Scientist
Cynicus – The statements that “global warming halted on this time period’ and “global warming of upper ocean halted on this time period’ both are correct, but the former requires an additional assumption. To heat lower levels of the ocean (below ~700m), heat would have to flow downward through the Argo network undetected. Such heat flow of a large enough value has not been observed, based on analyses discussed by Josh Willis on my weblog.
Albatross – The EOS article is introduced to document that we have identified a wide range of human climate forcings, beyond the radiative forcing of CO2. The IPCC is too conservative at presenting these other forcings. These are in addition to the human caused CO2 forcing.
Thus to conclude that I have ever not been concerned about the addition of CO2 and how it affects the climate system misrepresents my perspective. I am particularly concerned with respect to the biogeochemical effects of added CO2.
With respect to OHC, the objective conclusion is that the annual average heating of the well sampled upper ocean halted for at least a 4 year time period. This is a science question and should be addressed that way. To refute this claim, present data for these 4 years that conflicts with this finding.
This does not mean that future global warming will not occur. However, to better understand the climate system, we need to understand why this halt occurred. Moreover, we need to see if in the coming years the heating will be amplified so as to catch up to the model predictions.
Update #2: PM September 8 2010
In response to a comment on Skeptical Scientist that reads in part
RSVP at 03:48 AM on 9 September, 2010
Another “dumb” or “naive” question…
Why is oceans warming always published in Joules, while global warming is expressed in degrees Centigrade?
Thank you. You have actually very clearly framed the issue that is causing the misunderstanding in several of the above comments. You wrote
“Another “dumb” or “naive” question…
Why is oceans warming always published in Joules, while global warming is expressed in degrees Centigrade?”
The reason is that heat involves mass and Joules includes mass. When global warming is expressed as a trend in degrees Centigrade, it is incomplete, as this is just part of the heat. Jim Hansen agrees that the monitoring the ocean heat change is the most appropriate reservoir to monitor global warming (as he stated at a National Research Council meeting on the 2005 report
National Research Council, 2005: Radiative forcing of climate change: Expanding the concept and addressing uncertainties. Committee on Radiative Forcing Effects on Climate Change, Climate Research Committee, Board on Atmospheric Sciences and Climate, Division on Earth and Life Studies, The National Academies Press, Washington, D.C., 208 pp. http://www.nap.edu/openbook/0309095069/html/).
The only relevant issues in the above comments that pertain to this metric are the short duration of the lack of heating and the sampling issue. With respect to the later, satellite altimetry data is used to complement the Argo network. Except for ice covered areas (which is only a small fraction of the ocean), since 2004 the coverage is accepted by oceanographers as being adequate to diagnosis heating and cooling, within observational uncertainties as illustrated by Josh Willis in my Physics Today article.
The short duration of the lack of global average, annual cooling (4 years unless it extended beyond 2008) is correct. It may not have continued. However, the data is clear that for this period of time, global average annual upper ocean heating halted.
It is important to emphasize, of course, that this observation says nothing about the role of humans within the climate system, nor of the importance and cocern with the continued increase of CO2 in the atmosphere.
I note so far that none of the commenters have discussed the findings we presented in our paper
Pielke Sr., R., K. Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D. Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E. Philip Krider, W. K.M. Lau, J. McDonnell, W. Rossow, J. Schaake, J. Smith, S. Sorooshian, and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases. Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American Geophysical Union. https://pielkeclimatesci.files.wordpress.com/2009/12/r-354.pdf
UPDATE: PM September 8 2010
In response to a Reply On Skeptical Scientist which reads
“Moderator Response: Dr. Pielke – thank you for your comments. I am obliged to point out, with the greatest respect, that my argument seems to be validated by what you have written. Given the range of discussions regarding measurement, metrication and analysis, it is clear there is much work to be done, and that there is considerable uncertainty about ocean heat, its distribution and effects. On that basis, I must ask you how you come to make such definitive statements about one five year period. Your claim that the oceans did not gain heat during this period may be correct, but it is hardly proven, and certainly not representative of any consensus among those with sufficient expertise, such as Trenberth and von Schuckmann. This point of course must lead to my second observation: you have not addressed here the remark that so concerns me, and that was central to my entire argument. If ocean heat is not yet well understood, and many other indicators of global warming show warming – the cryrosphere in particular – how can you claim, as you did yesterday on your own blog, that a disputed measure of OHC “…means that global warming halted on this time period”. I do not find this claim at all convincing because you do not appear to have any evidence to support it (indeed the evidence, including your own comments here, suggest the assertion is flawed), and you have not addressed these points, which are the essential premises on which my argument stands.”
I have read the Reply [as Moderator] to my comment [I would appreciate if you could identify yourself. :-)]
On the issues, you seem to be assuming that climate change is synonymous with global warming. Global warming, however, is a subset of climate change.
“Global warming” occurs when Joules accumulate within the climate system, of which the oceans is the largest reservoir for heat changes within the climate system.
I agree that other climate indices have changed (e.g. Arctic and Antarctic sea ice), but these are not direct measures of global warming.
With respect to the quantitative accuracy of the upper ocean heat data, even Kevin Trenberth admits there is “missing heat” as discussed in the web posts that are in my Comment that I provided the links for earlier today.
Josh Willis, also, places uncertainly bars around his data in his figure in my paper
Pielke Sr., R.A., 2008: A broader view of the role of humans in the climate system. Physics Today, 61, Vol. 11, 54-55. https://pielkeclimatesci.files.wordpress.com/2009/10/r-334.pdf
so the statement such as “there was no global average warming in the upper ocean from 2004 to 2008” are consistent with his analysis. If they find an error, of course, that would need to be changed, but until it is, it is a robust, peer-reviewed scientific finding.
I still feel you are missing my main point. With all of the remaining unresolved uncertainties and systematic biases in the land surface portion of the multi-decadal global surface temperature trend, as we reported, for example, in
Pielke Sr., R.A., C. Davey, D. Niyogi, S. Fall, J. Steinweg-Woods, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, R. Mahmood, S. Foster, R.T. McNider, and P. Blanken, 2007: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Res., 112, D24S08, doi:10.1029/2006JD008229. https://pielkeclimatesci.files.wordpress.com/2009/10/r-321.pdf
Klotzbach, P.J., R.A. Pielke Sr., R.A. Pielke Jr., J.R. Christy, and R.T. McNider, 2009: An alternative explanation for differential temperature trends at the surface and in the lower troposphere. J. Geophys. Res., 114, D21102, doi:10.1029/2009JD011841. https://pielkeclimatesci.files.wordpress.com/2009/11/r-345.pdf
we should move towards the more appropriate global warming metric of heat which is Joules, most of whose changes occur in the ocean. The ocean below 700m does not seem to be a major reservoir for this heat, as discussed in the web posts I sent in my first Comment.
Even with the remaining issues with the quantitative accuracy of the ocean heat content measurements, it should become the primary metric to diagnose global warming and as a measure to compare with the IPCC models.
Until about 2004, the comparisons between the GISS model and the upper ocean heat content changes, for instance, were quite good as I reported on in my post
Update On Jim Hansen’s Forecast Of Global Warming As Diagnosed By The Upper Ocean Heat Content Change. https://pielkeclimatesci.wordpress.com/2010/05/21/update-on-jim-hansens-forecast-of-the-global-radiative-imbalance-as-diagnosed-by-the-upper-ocean-heat-content-change/.
Since 2004, however, the model predictions have not been as good. Perhaps, this is a short term effect associated with natural variability. If so, we should see a resumption of heating rates that were seen up to 2004. This comparison with models, as a test of their accuracy, is the basic scientific method of hypothesis testing.
Why you chose to label me a skeptic or a denier, besides being completely incorrect in this labeling, obscures the actual scientific issues and valuable discussions that could take place on your weblog.
I registered to post the text below as a comment on Skeptical Scientist in response to their post today
In order to assure that my view is accurately presented, I am posting a comment on your weblog. I appreciate that you have provided this opportunity.
There are several incorrect statements in your post.
First, as long as the sampling of the ocean heat is sufficiently dense, a snapshot is not cherry picking, as there is no lag involved.
A simple analog is a pot of water on the stove. When the burner is on, heat is added in Joules per second which results in the temperature increasing. By measuring the total heat of the water in the pot at any time, we can diagnosis the average rate of heating between sampling times. This integrated assessment is much more accurate than seeking to measure the heating rate itself.
In terms of the climate system, the heating rate is the global average radiative imbalance (which is made up of the radiative forcings and feedbacks). The difficulty of monitoring the fluxes, as contrasted with the integrated heat changes, is discussed in a series of weblog posts involving Kevin Trenberth and Josh Willis on my weblog; i.e.
My Perspective On The Nature Commentary By Kevin Trenberth https://pielkeclimatesci.wordpress.com/2010/05/24/comments-on-nature-commentary-by-kevin-trenberth/.
The issue of sea ice and glacial melt is not a significant component in the global average climate system heat changes, as presented in Table 1 in
Levitus, S., J.I. Antonov, J. Wang, T.L. Delworth, K.W. Dixon, and A.J. Broccoli, 2001: Anthropogenic warming of Earth’s climate system. Science, 292, 267-269. https://pielkeclimatesci.files.wordpress.com/2010/04/levitus2001.pdf.
As I wrote in
Pielke Sr., R.A., 2003: Heat storage within the Earth system. Bull. Amer. Meteor. Soc., 84, 331-335. https://pielkeclimatesci.files.wordpress.com/2009/10/r-247.pdf
“[T]here are several major reasons that the assessment of the earth system’s heat budget is so valuable.
• The earth’s heat budget observations, within the limits of their representativeness and accuracy, provide an observational constraint on the radiative forcing imposed in retrospective climate modeling.
• A snapshot at any time documents the accumulated heat content and its change since the last assessment. Unlike temperature, at some specific level of the ocean, land, or the atmosphere, in which there is a time lag in its response to radiative forcing, there are no time lags associated with heat changes.
• Since the surface temperature is a two-dimensional global field, while heat content involves volume integrals, as shown by Eq. (1), the utilization of surface temperature as a monitor of the earth system climate change is not particularly useful in evaluating the heat storage changes to the earth system. The heat storage changes, rather than surface temperatures, should be used to determine what fraction of the radiative fluxes at the top of the atmosphere are in radiative equilibrium. Of course, since surface temperature has such an important impact on human activities, its accurate monitoring should remain a focus of climate research (Pielke et al. 2002a).”
The recent data (2004-2008), according to Josh Willis, is quite robust in showing no global annual averaged upper ocean warming. This is also documented in the papers
Cazenave et al. Sea level budget over 2003-2008: A reevaluation from GRACE space gravimetry, satellite altimetry and Argo. Global and Planetary Change, 2008; DOI:10.1016/j.gloplacha.2008.10.004. http://sciences.blogs.liberation.fr/home/files/Cazenave_et_al_GPC_2008.pdf
Willis J. K., D. P. Chambers, R. S. Nerem (2008), Assessing the globally averaged sea level budget on seasonal to interannual timescales, J. Geophys. Res., 113, C06015, doi:10.1029/2007JC004517. http://www.agu.org/pubs/crossref/2008/2007JC004517.shtml
as I discuss in my post
Sea Level Budget over 2003–2008: A Reevaluation from GRACE Space Gravimetry, Satellite Altimetry and Argo by Cazenave et al. 2008. https://pielkeclimatesci.wordpress.com/2009/01/07/sea-level-budget-over-2003%e2%80%932008-a-reevaluation-from-grace-space-gravimetry-satellite-altimetry-and-argo-by-cazenave-et-al-2008/.
If the ocean data is further corrected for the period 2004 to 2008, I would, of course, change my conclusion.
The more important issue, however, is the recommendation that upper ocean heat content in Joules be used as the primary metric to monitor global warming.
In terms of the time since 2008, I suspect (and am waiting until the latest data is released this Fall) that upper ocean heating content increased during the recent El Nino. The radiative imbalance during this time period can then be compared with the models.
With respect to responding to comments, I would be glad to reply on your weblog in order to further clarify my perspective.
Finally, I propose that you discuss the conclusions that we reached in our paper
Pielke Sr., R., K. Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D. Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E. Philip Krider, W. K.M. Lau, J. McDonnell, W. Rossow, J. Schaake, J. Smith, S. Sorooshian, and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases. Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American Geophysical Union. https://pielkeclimatesci.files.wordpress.com/2009/12/r-354.pdf.