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Roger Pielke Sr. @ 7:00 am 

The 2007  HYPERLINK "http://www.ipcc.ch/SPM2feb07.pdf" IPCC Statement for Policymakers has a significant error that I have yet to see discussed.

The SPM reports on a “Total Net Anthropogenic” global average radiative forcing for 2005 of +1.6 [0.6 to 2.4] Watts per meter squared. When one converts the units, this means that the Earth’s climate system should be accumulating Joules at a rate of 2.61*10**22 Joules per year [0.98*10**22 Joules to 3.91*10*22 Joules per year] in 2005. 

The data, however, show quite a different accumulation of Joules in recent years, and in 2005 in particular. We have often argued that the ocean data has been shown to be an effective way to diagnose the radiative imbalance ( HYPERLINK "http://climatesci.colorado.edu/2005/08/08/comment-from-jim-hansen-on-the-august-2-climate-science-posting/" see and HYPERLINK "http://blue.atmos.colostate.edu/publications/pdf/R-247.pdf"  see). Jim Hansen, for example, has used the accumulation of heat in the upper oceans in the 1990s to bolster his claim of multi-decadal global climate prediction skill ( HYPERLINK "http://blue.atmos.colostate.edu/publications/pdf/1116592Hansen.pdf" see), where Jim Hansen wrote,

“The Willis et al. measured heat storage of 0.62 W/m2 refers to the decadal mean for the upper 750 m of the ocean. Our simulated 1993-2003 heat storage rate was 0.6 W/m2 in the upper 750 m of the ocean. The decadal mean planetary energy imbalance, 0.75 W/m2, includes heat storage in the deeper ocean and energy used to melt ice and warm the air and land. 0.85 W/m2 is the imbalance at the end of the decade.”

He further writes with respect to the radiative forcing record,

“As the record lengthens, the energy imbalance will provide an invaluable metric defining the task that humanity faces if it wishes to stabilize global climate.”

Well the radiative forcing data record is now longer, and it presents quite a different perspective than a more-or-less monotonic increase in the global radiative forcings as claimed by Jim Hansen. As shown in 

Lyman, J. M., J. K. Willis, and G. C. Johnson (2006),  HYPERLINK "http://www.agu.org/journals/gl/gl0618/2006GL027033/" Recent cooling of the upper ocean,
Geophys. Res. Lett., 33, L18604, doi:10.1029/2006GL027033.

“We observe a net loss of 3.2 (±1.1) × 10**22 J of heat from the upper ocean between 2003 and 2005. Using a broad array of in situ ocean measurements, we present annual estimates of global upper-ocean heat content anomaly from 1993 through 2005. Including the recent downturn, the average warming rate for the entire 13-year period is 0.33 ± 0.23 W/m2 (of the Earth’s total surface area)….”

See their Figure 1 where the accumulation and loss of heat as measured in Joules for the period 1993 to mid-2005 is shown.

This loss of heat from the upper oceans is also consistent with little if any heating in the troposphere over the last several years (e.g.  HYPERLINK "http://www.remss.com/msu/msu_data_description.html" \l "msu_decadal_trends" see the last several years in Figure 7 where the trends in the global average tropospheric and stratospheric temperatures are essentially zero). Even if the heat has been transported deeper into the ocean than the about 700m depth analyzed by Lyman et al, the radiative forcing that is available to alter the global average surface temperature trend is much less than reported in the 2007 IPCC SPM, and, indeed, for at least the period from 2003 to 2005 is a negative forcing! Thus, the data indicate a very different picture than presented by the IPCC. 

The global average surface temperature trend in the 2007 SPM (see Figure SPM-3 top in  HYPERLINK "http://www.ipcc.ch/SPM2feb07.pdf" the IPCC SPM) continues to show warming, but as has been summarized in

Pielke Sr., R.A., C. Davey, D. Niyogi, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, R. Mahmood, S. Foster, J. Steinweg-Woods, R. Boyles, S. Fall, R.T. McNider, and P. Blanken, 2007:  HYPERLINK "http://climatesci.colorado.edu/publications/R-321.pdf" Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Res. in press,

there is a significant warm bias in the construction of a global average surface temperature trend.

What these observations mean is that the statement in the IPCC SPM that there is a positive radiative forcing of 1.6 [0.6 to 2.4] Watts per meter squared in 2005 (when this was not true based on real data) is a particularly egregious error. Rather than relying solely on model based estimates to calculate a global radiative forcing, the authors of the IPCC Report should have also used real world data for the assessment of the net radiative forcing. 

A claim that a time period of several years is too short to assess the radiative heating is spurious as long as the sampling of the ocean heat content is sufficiently dense. As discussed in 

Pielke Sr., R.A., 2003:  HYPERLINK "http://blue.atmos.colostate.edu/publications/pdf/R-247.pdf" Heat storage within the Earth system. Bull. Amer. Meteor. Soc., 84, 331-335,

“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.”

The IPCC finding that the total 2005 net anthropogenic radiative forcing has a best estimate of +1.6 Watts per meter squared and that the total 2005 net radiative forcing has a best estimate of +1.72 Watts per meter squared is inconsistent with the observed changes in upper ocean heat content. The omission of a discussion of the conflict between real world observations and the model estimates of radiative forcing is a serious error in the IPCC SPM.

«  HYPERLINK "http://climatesci.colorado.edu/2007/03/02/missed-opportunity-by-the-ipcc/" Missed Opportunity By The IPCC   

3 Comments  HYPERLINK "http://climatesci.colorado.edu/2007/03/05/an-error-in-the-2007-ipcc-statement-for-policymakers-on-the-2005-global-average-radiative-forcing/" \l "postcomment" \o "Leave a comment" » 

Hello,

I have read in a linked onlinepaper, that, when the oceans should loose only a small part of their heatcontent, the global temperatures could rise dramatically. Does anybody know this paper?

Is this a result from computerclimatemodels?

Or was this news only a fake?

Best regards

Eddy 

Comment by Eddy — March 5, 2007 @  HYPERLINK "http://climatesci.colorado.edu/2007/03/05/an-error-in-the-2007-ipcc-statement-for-policymakers-on-the-2005-global-average-radiative-forcing/" \l "comment-146468" 9:30 am 

“A claim that a time period of several years is too short to assess the radiative heating is spurious as long as the sampling of the ocean heat content is sufficiently dense.” 

Question: Why has this claim been asserted? Over one complete year, shouldn’t the change in ocean heat content (Joules) approximately equal the radiative imbalance (Joules) at the top of atmosphere (assuming the upper ocean heat has not been transfered to the deep ocean)? Is there any scientific basis for claiming that large losses of heat from the ocean over multiple years is a short term effect of inherent system variability, or rather do you believe this cooling was forced by a poorly understood forcing (aerosols?) or negative feedback to such in the system? 

Comment by Bryan Sralla — March 5, 2007 @  HYPERLINK "http://climatesci.colorado.edu/2007/03/05/an-error-in-the-2007-ipcc-statement-for-policymakers-on-the-2005-global-average-radiative-forcing/" \l "comment-146484" 10:09 am 

Bryan- you have asked an excellent question.

It is clear from the mismatch between the IPCC SPM statement of the radiative forcing and the real world observations that we really do not adequately understand the natural variations of the climate system, as well as how the diverse range of human climate forcings influence these variations.

Joules are the currency that should be used to assess the radiative imbalance, and if the spatial sampling is sufficiently dense, this can be evaluated on very short time periods. See the weblog on this; “ HYPERLINK "http://climatesci.colorado.edu/2006/10/19/a-global-warming-currency/" A Global Warming Currency” which was posted on October 19 2006.

The multi-decadal global climate models used to provide “projections” for the coming decades has clearly failed a major test of their predictive skill.