Is ocean warming accelerating faster than thought? In a word, no.

There are a number of statements in Cheng et al. (2019) ‘How fast are the oceans warming’, (‘the paper’) that appear to be mistaken and/or potentially misleading. My analysis of these issues is followed by a reply from the paper’s authors.

Contrary to what the paper indicates:

  • Contemporary estimates of the trend in 0–2000 m depth ocean heat content over 1971–2010 are closely in line with that assessed in the IPCC AR5 report five years ago
  • Contemporary estimates of the trend in 0–2000 m depth ocean heat content over 2005–2017 are significantly (> 95% probability) smaller than the mean CMIP5 model simulation trend.

Ocean warming over 1971–2010 per IPCC AR5 and contemporary estimates

1. The paper states: “The warming is larger over the 1971–2010 period than reported in AR5. The OHC trend for the upper 2000 m in AR5 ranged from 0.20 to 0.32 Wm−2 during this period (4: AR5). The three more contemporary estimates that cover the same time period suggest a warming rate of 0.36 ± 0.05 (6: Ishii ), 0.37 ± 0.04 (10: Domingues), and 0.39 ± 0.09 (2: Cheng) Wm−2.” [Numbered references in this article are to the same numbered references in the paper. The number is followed by the lead author’s name, or AR5, where this aids clarity.]

2. AR5 (4) featured 0–700 m depth ocean heat content (OHC) 1971-2010 linear trend estimates from five studies, ranging from 0.15 to 0.27 Wm−2  of the Earth’s surface. Adding the AR5 700–2000 m OHC 1971-2010 trend estimate of 0.09 Wm−2  brings the range up to 0.24 to 0.36 Wm−2 , not to 0.20 to 0.32 Wm−2 as stated. The warming rates plotted in Supplementary Figure S1 agree to my values, not to those stated in the paper.

3. Importantly, although AR5 featured several OHC trend estimates for 0–700 m depth, its assessment of the Earth’s energy uptake (Section 3.2.3 and Box 3.1) used only the highest one (10: Domingues), adding the Levitus (12) 700–2000 m OHC trend to give a best estimate 0–2000 m warming rate over 1971–2010 of 0.36 Wm−2. That rate is identical to one (6: Ishii) of the three more contemporary estimates given in the paper and extremely close to the other two of them – within the innermost one-third of their uncertainty ranges.

See Figure 1, left hand section, and compare with the ‘Updated OHC estimates compared with AR5’ figure [Fig 2] in the paper. It is therefore misleading to claim that the warming is larger over the 1971–2010 period than reported in AR5.

4. Moreover, over the final decade covered by AR5, 2002–2011, the trend of the 0–2000 m OHC time series that AR5 adopted for its assessment, 0.60 Wm−2, was noticeably higher than those for two of the three more contemporary estimated OHC datasets given in the paper (0.35 (6: Ishii) and 0.52 (2: Cheng) Wm−2) and, unsurprisingly, almost identical to the third (10: Domingues + 12: Levitus).

Figure 1: Updated 0–2000 m OHC linear trend estimates compared with AR5 and the CMIP5 mean. Error bars are 90% confidence intervals; black lines are means. Units relate to the Earth’s entire surface area.

Ocean warming over 2005–2017 per CMIP5 models and contemporary estimates

5. The paper’s ‘Past and future ocean heat content changes’ figure [Fig 1] caption states: “Annual observational OHC changes are consistent with each other and consistent with the ensemble means of the CMIP5 models for historical simulations pre-2005 and projections from 2005–2017, giving confidence in future projections to 2100 (RCP2.6 and RCP8.5).” This does not appear to be true for the linear trends of the annual values for the 2005–2017 projections, at least.

The main text states: “Over this period (2005–2017) for the top 2000 m, the linear warming rate for the ensemble mean of the CMIP5 models is 0.68 ± 0.02 Wm−2, whereas observations give rates of 0.54 ± 0.02 (2), 0.64 ± 0.02 (10), and 0.68 ± 0.60 (11) Wm−2.”

6. Five problems with this claim regarding 2005–2017 warming rates are:

(i)    the CMIP5 RCP2.6 and RCP8.5 projections top 2000 m OHC data archived for the paper shows an ensemble-mean linear warming rate over 2005–2017 of 0.70 ± 0.03 Wm−2, not 0.68 ± 0.02 Wm−2. The same is true when also including data from the third scenario used in the paper (RCP4.5).

(ii)  the underlying time series from which the third observational estimate is derived (Fig. 3.b in 11: Resplandy) spans 1991–2016, and has a lower (and highly uncertain) linear trend from 2005 to 2016 (its final year) than the stated 0.68 Wm−2­ (which is calculated over 1991–2016), so this estimate should be excluded;

(iii) the statement inexplicably omits the Ishii et al. (6) observational data, which also have a lower estimated trend (0.62 ± 0.07 Wm−2) than per CMIP5 over this period; and

(iv)  the uncertainty range for the Cheng (2) estimate appears to be seriously understated: I calculate that the estimate should be 0.54 ± 0.06 (rounding 0.055 up), not 0.54 ± 0.02.

(v)  adding the uncertainty ranges in quadrature, since CMIP5 and observational errors are independent, the CMIP5 ensemble mean trend is statistically inconsistent with the all three of these observational trend estimates (2: Cheng, 6: Ishii, 10: Domingues);

The right hand section of Figure 1 shows a corrected comparison of  CMIP5 mean and observational 0–2000 m depth ocean warming rates over 2005–2017.

7. Although it is pointed out in the paper’s Supplementary material that volcanic eruptions after 2000 have not been taken into account in CMIP5 models (with a minor effect on projected warming since then), it has been shown that when underestimation of other growth in other drivers of climate change is accounted for there is no overall bias in post-2000 CMIP5 model forcing growth (Outten et al. 2015).

Other issues

8. The straight black line in the ‘Past and future ocean heat content changes’ figure [Fig 1] for the Resplandy et al. (11) OHC estimate gives a misleading impression of close agreement with the three OHC time series based on in situ observations over 1991–2016: its trend uncertainty range is so large (0.08 to 1.28 Wm−2) that the apparent close agreement is most likely due to chance.

9. The Press release for the paper claimed that ‘If no actions are taken (“business as usual”), the upper ocean above 2000 meters will warm by 2020 ZetaJoules by 2081-2100″, which is based on CMIP5 model RCP8.5 scenario simulations. That is misleading. RCP8.5 involves not only no actions (including those already carried out) being taken, but also emissions being unusually high for a business as usual scenario.[ii]

Nicholas Lewis                                                                                          January 2019

[i]  The paper does not directly claim that ocean warming is accelerating faster than thought; that is the headline of The New York Times article about the paper.

[ii]  As the source paper (Riahi, K., et al., 2011: RCP 8.5–A scenario of comparatively high greenhouse gas emissions. DOI 10.1007/s10584-011-0149-y) states: “RCP8.5 combines assumptions about high population and relatively slow income growth with modest rates of technological change and energy intensity improvements, leading in the long term to high energy demand and GHG emissions in absence of climate change policies.”, and that “[RCP] 8.5 corresponds to a high greenhouse gas emissions pathway compared to the scenario literature”. As Riahi et al. (2011) make clear, the assumed energy intensity improvement rates are only about half the historical average while middling world GDP growth is assumed, leading to coal use increasing almost 10 fold by 2100.

2. L. Cheng et al., Sci. Adv. 3, e1601545 (2017).
4. M. Rhein et al., in Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, T. F. Stocker et al., Eds. (Cambridge Univ. Press, 2013), pp. 215–315.
6. M. Ishii et al., Sci. Online Lett. Atmos. 13, 163 (2017).
10. C. M. Domingues et al., Nature 453, 1090 (2008).
11. L. Resplandy et al., Nature 563, 105 (2018).
12. S. Levitus et al., Geophys. Res. Lett. 39, L10603 (2012).
Additional references
Cheng, L., Abraham, J., Hausfather, Z. and Trenberth, K.E. (2019). How fast are the oceans warming?. Science, 363(6423), pp.128-129.
Outten, S., P. Thorne, I. Bethke, and Ø. Seland (2015), Investigating the recent apparent hiatus in surface temperature increases: 1. Construction of two 30-member Earth System Model ensembles, J. Geophys. Res. Atmos., 120, doi:10.1002/2015JD023859


Lijing Cheng has asked me to post also the following reply from the paper’s authors to my critique. I am pleased to do so and I thank him for providing it. I have replaced interspersed text extracted from my article with paragraph number references.  The authors’ responses are shown in blue. I have appended my comments, shown in red, on a number of them. 

Paragraphs 1 and 2

Some questions have been raised concerning the numbers in our article (…) and indeed there is an inconsistency between a value in the supplementary material and the main text.  It relates to the use of linear trends and how to assign a change over various periods.  For longer time intervals, a linear trend is not a good fit to the data and use of that to assign a change can be misleading.  In the IPCC AR5, below 700m depth, it is stated that “the heating below 700 m is 62 TW for 1971-2010”.  They also state “For the ocean from 2000 m to bottom, a uniform rate of energy gain of 35 [6 to 61] TW from warming rates centred on 1992–2005 (Purkey and Johnson, 2010) is applied from 1992 to 2011, with no warming below 2000 m assumed prior to 1992.”  Hence the difference for the 700 to 2000 m layer is 62 -35 = 27 TW.  This is 0.05 W m-2 and is what was used in the main text to produce the numbers quoted.   However, if instead one takes the 2 flat lines below 2000 m and subtracts from the actual values, and then fits a linear trend, the implied change is closer to 45 TW which gives the 0.09 W m-2 plotted in Fig. S1.  If the latter is used instead, then the change from the old AR5 values to the newer OHC values is somewhat reduced (see figure below).  The increase is up to 40% over the prior IPCC estimates, and the average is 24%.  This exercise was prompted by a comment by Nic Lewis who we thank, and it highlights the uncertainty in actual trends and their use to depict changes.  The conclusions in our Perspective remain sound. If the alternative analysis method proposed by Nic Lewis is used, the change is not quite as dramatic as implied in some of the associated press releases.

Based on this:

  • While there is an inconsistency that is not discussed between Fig. 2 and Fig S1, it reflects the uncertainties in previous OHC estimates and the associated methods. In particular, some values before 1980 or so are erratic (high values in the 1960s) and a linear trend is not a good fit to the time series.
  • All of our key points are still valid: (1) the best estimates are collectively higher than the 5 estimates featured in AR5 (0-63% higher). (2). And the best estimates are more consistent with each other (0.36/0/37/0.39 Wm−2 than 0.24~0.36 Wm−2 in AR5). (3). Model ensemble means are higher than 5 estimates featured in AR5 (0.39 Wm−2, 8-63% higher) and consistent with new/updated observations.
  • AR5-Box 3.1 used the strongest estimate without backup literature, we state this in the supplement (also read our replies below). So our study justifies the choice in Box 3.1 as we discussed in supplement. The new estimates could be 0-8% stronger than the selected estimate by AR5-Box 3.1 for 1971-2010. But we didn’t make claims regarding Box 3.1 in Science article, so this is not an issue.
  • This would be an adjusted Fig. 2 (plot below) if we used the different value, the key messages do not change:

Additionally, the Domingues value for 0-700m should have extremely large error bars: all of the values prior to 1970 are much higher than from 1970 to 1980 in AR5, (see AR5 Figure 3.2; given also below) and hence the trends for that estimate are extremely dependent on the period used.  Whether that value was used or not in AR5 (and we state it was), the AR5 message is that they really didn’t know the value at all well, and now we do.

Nic Lewis comments:

a) Their arguments justifying their deduction of 35 TW from the AR5 1971–2010 linear trend below- 700 m ocean heating rate to give their 700–2000 m layer heating rate of 27 TW (0.053 Wm−2) make no sense. AR5 arrived at its sub-700 m deep OHC time series (plotted in Box 3.1 Figure 1) by adding, from 1992 onwards, { (year – 1991) * 1.10 ZJ } to its estimate of 700–2000 m depth OHC [1.10 ZJ / year = 35 TW].

The only correct way to derive the AR5 700–2000 m depth OHC time series is to take its sub-700 m OHC time series and reverse out this addition, which is what I did. Cheng et al.’s method gives the wrong 1971–2010 rate of 700–2000 m depth ocean heating irrespective of whether this is measured by a linear trend or otherwise.

b) Their explanation of the inconsistency between their Fig 2 and their Fig S1 conflicts with the facts. They imply in the supplementary material that for both figures the warming rates are linear trends from an ordinary least squares (OLS) fit. Whether or not an OLS fit is ideal is irrelevant; it is what AR5 did and is what Cheng et al. indicated they did. I have verified that their Fig S1 estimates agree to OLS fits to their data. It is undeniable that the AR5 warming rates plotted in their Fig 2 are erroneous.

c) Numerical simulations using strongly autocorrelated random errors confirm that the 1971–2010 trend uncertainty for the Domingues 0–700 m OHC trend stated in AR5, which is incorporated in the AR5 0–2000 m trend uncertainty plotted in my Fig 1, appears to adequately reflect the large uncertainty that AR5 showed the Domingues estimates as having in pre-Argo years (which dominates the uncertainty shown in Box 3.1 Fig 1).

Paragraph 3

Please read our supplement, we fully describe the whole story as follows :

“IPCC-AR5 (1) featured five estimates for OHC within 0-700m including Levitus et al. (2) (LEV), Ishii et al. (3) (ISH), Domingues et al. (4) (DOM), Palmer et al. (5) (PAL), Smith and Murphy (6) (SMT), one estimate for 700-2000m: Levitus et al. (2) (LEV) and one estimate below 2000 m: Purkey and Johnson (7) (PG). For the Earth’s energy budget inventory (Box 3.1 in Ref. (1)) and other places, DOM, LEV and PG are used for 0-700m, 700-2000m, and below 2000m respectively. Among the five 0-700m OHC estimates in AR5, the minimum yields an ocean warming of 74 [43 to 105] TW (SMT) within 1971-2010, which is almost half of the maximum, with a rate of OHC change of 137 [120 to 154] TW (DOM). If all of five estimates are treated equally, a huge error bar has to be put in the final OHC estimate, downplaying the reliability of OHC records.

AR5 chose the DOM estimate to assess Earth’s energy budget, rather than any others or an ensemble mean of the five featured estimates by stating:

‘Generally the smaller trends are for estimates that assume zero anomalies in areas of sparse data, as expected for that choice, which will tend to reduce trends and variability. Hence the assessment of the Earth’s energy uptake (Box 3.1) employs a global UOHC estimate (Domingues et al., 2008) chosen because it fills in sparsely sampled areas and estimates uncertainties using a statistical analysis of ocean variability patterns.’

In this way, the ‘conservative error’ of many estimates has been identified in AR5 but not supported by the literature. Since AR5, many studies have been looked into this issue either directly or indirectly (8-13) and several new/revised estimates are available, and are chosen by our study.

For OHC within 0-700m, the new CHG and ISH estimates are consistent with DOM (Figure S1). The three estimates are collectively higher than LEV/ISH/PAL/SMT featured in AR5 (Figure S1). Therefore, the progress after AR5 justifies the choice of DOM in AR5 for OHC 0-700m.”

We note that the AR5 featured five different OHC estimates available at the time in the main body of their assessment and the main figure (Fig. 3.2), shown below. We feel that this justifies comparing newer OHC estimates to all five series, rather than just the Domingues series that the AR5 chose to highlight.
Additionally, when the 700-2000m values from Levitus are used (as discussed above), recent records still show 0% to 8% more warming over the 1971-2010 period than the AR5 Domingues value: 0.36 ± 0.05 (Ishii), 0.37 ± 0.04 (Domingues+Levitus), and 0.39 ± 0.09 (Cheng) compared to the old Domingues value of 0.36 Wm−2.

Incidentally, since we have this figure here: note the big bump in Domingues in the top panel in the 1950s and 60s.  Also note the bump in the 1970s in the 700 to 2000 m layer.

Nic Lewis comments:

None of these points affects what I say in my article. The paper says ” These recent observation-based OHC estimates show highly consistent changes since the late 1950s (see the figure). The warming is larger over the 1971–2010 period than reported in AR5. The OHC trend for the upper 2000 m in AR5 ranged from 0.20 to 0.32 W m−2 during this period (4).” Since the figure referred to shows only 0–2000 m OHC, it is implicit that ” The warming is larger over the 1971–2010 period” in the next sentence refers to warming in the 0–2000 m ocean layer. AR5 only featured 0–700 m OHC dataset other than Domingues when discussing warming of that ocean layer; it did not use any of them to estimate warming over 0–2000 m .

Paragraph 4

The period from 2002-2011 seems somewhat arbitrary, and we chose to focus on the 1971-2010 period as it was the one specifically highlighted in the AR5. We would expect greater agreement between older and newer estimates of OHC changes after around 2005 (when Argo data begins being available), as corrections of XBT measurements and better spatial interpolation approaches – which were the primary changes made to newer OHC datasets – matter much more prior to the early 2000s. And there is a better agreement after 2005, Johnson et al. 2018 BAMS state of climate show this already. We do give updated values for 2005-2017 (Argo period) for comparison with CMIP5.

Further, we could see the time series plot similar to AR5-Fig.3.2 below, the new time series apparently show better consistency than AR5-Fig. 3.2 among estimates.Figure.  Times series of OHC 0-2000m for the four best estimates compared with CMIP5 model ensemble mean and two-sigma model spread.

Nic Lewis comments:

My paragraph 4 is simply an observation; it does not claim to point to any mistake in the paper. Nor does it bear on my point that it is misleading to claim that the warming is larger over the 1971–2010 period than reported in AR5.

Paragraph 5

First, 2005-2017 is a short period, there are many uncertainties: 1) There are short-term variability in the time series (i.e. Interannual variability such as ENSO) and uncertainty in observations, these can impact the trend calculation in a short period within 2005-2017;  2) CMIP5 models do not contain natural variability in phase with actual natural variability, and 3) do not contain realistic forcings after 2005. We discuss this in some detail in supplement:

“We show in the main text that over the period of 2005-2017, the linear warming rate for the ensemble mean of the CMIP5 models is 0.68±0.02 W m-2, slightly larger than the observations (ranging from 0.54±0.02 to 0.64±0.02). Many studies, including Gleckler et al. (13) and Schmidt et al. (16) have shown that the volcanic eruptions after 2000 have not been taken into account in CMIP5 models. Taking this into account, the Multi-Model-Average of CMIP5 simulations will be more consistent with observations during the recent decade (13).”

Gleckler et al. 2016 explicitly addressed the volcano impacts in ocean heat content comparison between model and observations, after Outton et al. 2015, they suggested a correction for a global volcanic aerosol forcing since 2000 of 0.19±0.09 Wm−2.

Nic Lewis comments:

None of this is relevant to my point that the claim in the caption to Fig 1 of the paper that “Annual observational OHC changes are consistent with each other and consistent with the ensemble means of the CMIP5 models for historical simulations pre-2005 and projections from 2005–2017” is contradicted by the differences in the linear trends of the data involved over 2005–2017, having regard to the trend uncertainty ranges.

Paragraph 6

(i)   As we point out in the supplementary materials (figure caption) “CMIP5 results (historical runs from 1971 to 2005 and RCP4.5 from 2006 to 2010) are indicated by the green bar”. Using CMIP5 historical + RCP4.5 runs gives us 0.68 ± 0.02 Wm−2. We could have been clearer in the main paper which RCP runs were shown in the trends comparison part of the figure; we did in earlier drafts of the article but it was cut at the suggestion of the editors at Science to shorten/simplify the figure caption.

(ii)  Resplandy explicitly state in their paper that the trustable estimate is the linear trend, rather than annual values, because the O2 and CO2 changes on annual scales are not primarily driven by temperature. Hence we only use their linear trend (the revised version shown in Real Climate).

(iii) Earlier drafts of the paper did include the Ishii estimate, though it was omitted from the final version due to length constraints as it fell between the 0.54 (Cheng) and 0.64 (Dom/Lev) instrumental estimates noted. We should have made this clearer (e.g. mention that instrumental estimates range from 0.54 to 0.64), although its exclusion here does not impact any of our conclusions. As the 0.62 Ishii estimate is closer to the Dom/Lev than Cheng, its inclusion would make the overall range of instrumental estimates seem closer to CMIP5 over this period.

(iv)  We used the error calculation presented in Foster and Rahmstorf 2011, which takes accounts of the autocorrelations in a time series.



  • OHC_se is standard error using OLS.
  • v=1+2*p1/(1-q)
  • p1=OHC_autocorrelation(2)
  • q= OHC_autocorrelation(3) / OHC_autocorrelation(2)
  • OHC_autocorrelation is the autocorrelation of the time series.

Using this method, we can replicate the error bar provided by AR5, so it should be nearly identical to AR5 method.

We also get 0.06 uncertainty range for Cheng (2) if simply using OLS method. But this does not impact the comparison between new/updated observations and model.

(v)  The four new/updated best estimates are 0.54, 0.62, 0.64, and 0.68 Wm-2. The CMIP5 historical + RCP4.5 model ensemble mean is 0.68 Wm-2. If we focus on instrumental estimates (and exclude Resplandy et al given its large uncertainties), the CMIP5 models are a bit higher than observations during the Argo era, although, as we discuss in the Supplementary Materials and our previous replies, mismatches between projected and observed forcings in the forecast period are expected to give differences over this period.

Nic Lewis comments:

(i)    No indication is given in the paper or the supplementary material that “the linear warming rate for the ensemble mean of the CMIP5 models” for the top 2000 m over 2005–2017 referred only to projections based on the RCP4.5 scenario. Although the authors were unlucky to have an editor who was more concerned with presentation than scientific content, they, not the editor, are ultimately responsible for the paper.
The caption to their Fig 1, which states that annual observed OHC changes are consistent with the ensemble means of the CMIP5 models, shows projections based on the RCP2.6 and RCP8.5 scenarios. The relevant 2005–2017  trends for those scenarios are respectively 0.70 and 0.71 Wm-2.

(ii)  This supports my point that the 2005–2017 trend estimatable from the (revised) Resplandy data is highly uncertain. The fact that the estimated 1991–2016 Resplandy trend is somewhat less uncertain (at 0.68 ± 0.60 Wm-2) does not justify treating it as also being the 2005–2017 trend. The fact is that the information available from the Resplandy data is so imprecise that it adds almost nothing to knowledge about ocean warming trends over 2005–2017.

(iii) Noted. IMO this issue illustrates a problem with publishing papers in Science and similar ‘high profile’ journals.

(iv) I also used the error calculation presented in Foster and Rahmstorf 2011. I estimated the relevant autocorrelations over 2005–2017, since that was the period over which the trend was being estimated. They were insignificantly negative for the Cheng data, so no correction to the OLS standard error  estimate of 0.0332 was appropriate. Multiplying this by 1.65 gives a 5–95% uncertainty range of, rounded up, ±0.06. The authors appear to agree with this value. I cannot understand how a correction for autocorrelation could possibly reduce the uncertainty range by a factor of three in these circumstances. The paper’s ±0.02 uncertainty range for the Cheng 0–2000 m 2005–2017 trend seems clearly wrong.

(v)  Using data only from the RCP4.5 scenario simulations, giving an ensemble mean lower than that for RCP2.6 only, for RCP8.5 only, and for all three scenarios combined, appears to be unjustified (even if had been disclosed).

Paragraph 7

Gleckler et al. 2016/Santer et al. 2014 (cited in our supplement) explicitly addressed the volcano impacts, after Outton et al. 2015, see our previous reply.
Schmidt, A., Mills, M. J., Ghan, S., Gregory, J. M., Allan, R. P., Andrews, T., et al. (2018). Volcanic radiative forcing from 1979 to 2015. Journal of Geophysical Research: Atmospheres, 123.

Nic Lewis comments:

This is irrelevant. Outten et al 2015 also included the omission in CMIP5 models of the impacts of recent volcanic eruptions, but found that it was fully offset by the net impact of misestimation of recent changes in other forcings.

Paragraph 8

We agree that the uncertainties in the revised Resplandy estimate are quite large, as we note when including them in the paper over the 2005-2017 Argo period (0.68 ± 0.60 Wm−2). Unfortunately showing the error bars of all the underlying observational series in main text figure as well as those of the climate models would have made it unreadable, and the fact that the Resplandy estimate does not extend back to 1971 means that it is left out of the “Updated OHC estimates compared with AR5” portion of the figure that does show individual series uncertainties. However, Resplandy et al does provide a novel approach to estimating ocean heat content, and we think their median estimate was worth showing alongside the three updated instrumental datasets, even if (unlike the other three datasets) Resplandy’s uncertainties are so large that they limit the claims that can be made regarding agreement with climate models.

Paragraph 9

We agree it is generally better to include the full definition of RCP8.5 to avoid any confusion, but in a press release for the general public we had to simplify. This does not impact the message in the published Science article. We note that there is an ongoing debate within the energy modeling and climate science community regarding RCP8.5 and the extent to which it represents a “business as usual” outcome, and that this is shifting with the availability of the SSP scenarios and the inclusion of a 7 w/m^2 forcing scenario in CMIP6. However, references to RCP8.5 as “business as usual” in the published literature are quite common, and the original paper presenting the RCP8.5 scenario (Riahi et al: explicitly refers to it as “a high-emission business as usual scenario”.

Closing statement by the paper’s authors:

  1. Thanks for the critique, an alternative set of values could be used in Fig.2 in our calculation for 700-2000m OHC in AR5. But the uncertainties are large in those early years.
  2. We believe that all of our conclusions are still valid:
  • After significant progress since AR5, the best OHC estimates show stronger warming than estimates featured in AR5 (0~63%), and they are also more consistent with each other.
  • The models are consistent with the best OHC estimates for the 1971-2010 period. While models are warming slightly faster than most of the observational records during the 2005-2017 period, this is expected because the volcanic aerosol effects are not fully included.

Nic Lewis closing comment:

I thank the authors for their constructive response. I concur that OHC uncertainties are large in the early years of the 1971–2010 period.

None of the authors’ responses refute any of my criticisms concerning factual errors and misleading statements in the paper.

In particular, presenting my method of calculating AR5 0–2000 m warming rates over 1971–2010 as alternative to their method is like claiming that calculating 4 –  2 = 1 is an alternative to calculating  4 – 2 = 2.

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January 22, 2019 10:22 am

“How fast are the oceans warming?” How fast is the integrity of science declining? To say that something IS warming requires either a time machine or a decision to regard climate science as theology. How about just writing a paper about the data, without the obligatory preaching about greenhouse gases? No, theology it is.

R Shearer
Reply to  climanrecon
January 22, 2019 12:54 pm

Damn ye, heretic. No afterlife (or funding) for you.

Reply to  climanrecon
January 22, 2019 3:46 pm

There is no data. Man has no capability of measuring ocean temperature.

mike the morlock
Reply to  Gamecock
January 22, 2019 5:26 pm

Gamecock January 22, 2019 at 3:46 pm
There is no data. Man has no capability of measuring ocean temperature.

Yes we do, its called “the big toe”


Reply to  mike the morlock
January 22, 2019 7:25 pm

That’s the problem, Michael. One toe reading for 1,333,000,000 cubic kilometers. 10,000 toe reading would put you no closer to knowing the oceans’ temperature.

Louis Hooffstetter
Reply to  Gamecock
January 22, 2019 8:04 pm

Climate scientists can determine how fast the oceans are warming with the same degree of precision and accuracy as they can count how many angels can dance on the head of a pin.

I just wish they would use significant figures correctly.

January 22, 2019 10:31 am

I’ll start to prepare my food for boiling in ocean 😀

January 22, 2019 10:45 am

I find it at least refreshing to have responses from the authors of this paper that at least attempt to refute the noted discrepancies.
I’d rather have real scientific discussions than ad hominem and playground repartee.

Louis Hooffstetter
Reply to  Rocketscientist
January 22, 2019 8:09 pm

Forgive us, but here we thrive on playground repartee (as well as scientific discussion).
Ad hominens, not so much.

January 22, 2019 10:47 am

‘Is ocean warming accelerating faster than thought?’
Sloppy English.
‘Is ocean warming accelerating faster than has so far been thought?’, or maybe ‘Is ocean warming faster than previously thought?’ would be clearer.

Douggie Fresh
Reply to  Carbon500
January 22, 2019 11:40 am

“Sloppy English” = redundant English

Reply to  Douggie Fresh
January 22, 2019 2:14 pm

The sloppy English is saying accelerating instead of increasing.

It’s also sloppy science, since the paper fitted linear trends to the whole period, there was ZERO acceleration found. So unless anyone though OHC was slowing down zero acceleration is NOT “faster than thought”.

But hey this is only the NYT, who would expect professional journalists to know how to write ??

Douggie Fresh
Reply to  Carbon500
January 22, 2019 11:44 am

Huh…Based on your suggestions, I would say the original sufficed as you clearly understood the meaning.

Reply to  Carbon500
January 22, 2019 1:36 pm

If his thoughts can’t move faster than a warming ocean, then that points to a different type of problem.

Reply to  Carbon500
January 22, 2019 1:57 pm

“The water in Majorca don’t taste like what it ought to”.

Reply to  Carbon500
January 22, 2019 2:00 pm

Good point.

I’m pretty sure most of us can think faster than the ocean can warm. 🙂

Kurt in Switzerland
January 22, 2019 10:52 am

I have always been highly skeptical of calculations of “Ocean Heat Content” (let alone efforts to calculate changes in the same over time) absent accurate, reliable measurements of deep oceans (everything below 2,000 m).

That that said, the following caveat / comment caught my eye:

“Other issues

8. The straight black line in the ‘Past and future ocean heat content changes’ figure [Fig 1] for the Resplandy et al. (11) OHC estimate gives a misleading impression of close agreement with the three OHC time series based on in situ observations over 1991–2016: its trend uncertainty range is so large (0.08 to 1.28 Wm−2) that the apparent close agreement is most likely due to chance.”

‘Misleading’ would appear to be a kind modifier. Isn’t this supposed to be about science? If so, when did blatant guesswork get a free pass?

Rud Istvan
Reply to  Kurt in Switzerland
January 22, 2019 1:04 pm

You may be right. But the recent ARGO post showed that deep ocean water has a remarkably stable (and uniform across latitudes) temperature, so it may not be as big a problem as you surmise.
This is because deep water is mainly part of the thermohaline circulation. This is driven by the formation of surface sea ice. As seasonal sea ice forms near the poles, it exudes brine. The resulting saltier surface water is denser and sinks to the bottom. The temperature of this water is a function of surface sea ice formation, so is always near OC. (The freezing point of seawater is ~28.4F or -2C depending on salinity.)
As a single example, two research voyages across the deep Southern Pacific in 2005 and 2014 both found the deep water (all that below 2000 meters) to be in both sample years 0.0216+/-0.0126 F.

Reply to  Kurt in Switzerland
January 22, 2019 4:56 pm

I’m not even sure if the term “Ocean Heat Content” has any meaning. Heat is not a quantity, it is a process for transferring energy and is measured in joules. I think the term has been mixed up with “Heat Capacity” of the ocean which relies on the value of the specific heat for sea water.

Alarmists want us to think that this “Ocean Heat Content” will suddenly burst out of the oceans and fry us all. Poor use of physics.

Reply to  leitmotif
January 22, 2019 5:08 pm

I should have said heat is not a property of something.

Louis Hooffstetter
Reply to  leitmotif
January 22, 2019 8:15 pm

“Alarmists want us to think that this “Ocean Heat Content” will suddenly burst out of the oceans and fry us all. Poor use of physics.”

Yep. Climate scientists aren’t known for their proper use of physics (or any other branch of science or mathematics for that matter).

Reply to  leitmotif
January 23, 2019 9:43 am

Heat certainly is a quantity. What a strange comment! How much heat does it take to boil a litre of water at sea level, assuming the water is at 0 degrees C with no ice? The answer is a number of Joules, certainly a quantity.

January 22, 2019 11:51 am

Now, this is how “peer review” should work.

Reply to  Neil Lock
January 22, 2019 12:21 pm

Right, Nick! Now how can get more of this approach?

I suggest that every scientific paper published online should be required to have a comments section that would allow anyone to comment on the paper. The only limitation should be rejection of objectively grossly uncivil comments.

Reply to  Neil Lock
January 22, 2019 1:02 pm

peer review was never meant to work this way… one would have the time

peer review was meant to put it out there…throw it at the wall..then this happens….and see if it sticks

January 22, 2019 11:52 am

Even after ARGOS, any estimate of the average temperature for the top 2000 meters of the ocean is little better than a guess.
Prior to ARGOS, any estimates of the average temperature for the top 2000 meters is indistinguishable from throwing darts at a board.

Rud Istvan
Reply to  MarkW
January 22, 2019 1:22 pm

Actually, taking my recent post on ‘ARGO fit for purpose?’ ARGO mission design spec (10W/square meter OHC for highest resolution ‘pixel’ 1000km on a side) and the numbers for annual W/square meter Nic cites as current estimates ( ranging around 0.6) we should have a decent first ARGO estimate on OHC change around (10/0.6) 17 years from 2005 full deployment, or about 2022. Until then everything is IMO a guesstimate.
This is another physical reason Willis Eschenbachnis right in his criticism of OHC error bars.

Reply to  MarkW
January 22, 2019 7:42 pm

I want to thank the authors for answering questions and responding as they have. They may think they’re thrown to the lions in the Roman Coliseum here at WUWT, but shouldn’t. I appreciate this give and take. I also appreciate that they immediately disavowed the Headline, but without a letter to the Editor saying such, 90% of the damage has been done and won’t be undone. That, in a nutshell is what drives most of us crazy.

Much thanks to Nic. This is not a topic I’ve looked at in any detail, but it seems “Oceans Heating Up Dangerously” is all the rage in the MSM lately, and I guess it is time to dig in.

January 22, 2019 1:33 pm

am impressed that they answered.

Cannot recall seeing anything about large error bands and early information being sketchy in the news report.

That part doesn’t fit a tidy narrative.

Reply to  troe
January 23, 2019 6:10 am

Error bars are fundamental to any statistical analysis of measurement data. They shouldn’t even be applied until an adequate sample, and period of sampling, has been attained. This annual temperature “watch” (or monthly or daily) in climatology moves data analysis away from the whole concept of climatology. Owing to the lengths of some recognized cycles , and variations in the length of various cycles, even the 30 years assigned by WMO is barely adequate. It should, however, be the minimum until redefined. Even then, I often used a progressive diminution of error bars as evidence of closing in on the “truth”. When variation begins to level out you might be getting close to a meaningful error estimate. Simply using short-term error bars in a complex model, especially if a number of variables are involved, begs compounding projected error. Stating that some observation is statistically significant is ridiculous until measurement is tested. This is why IPCC “votes” on, and assigns ludicrous reliability (likelihoods) of observed measurements (all are meaningless).

January 22, 2019 1:47 pm

In short, our guesses are better than others guesses because of ‘models’ and our work got lots of headlines the one true mark of value in climate ‘science ‘

January 22, 2019 2:43 pm

Isn’t the word estimable, not estimatable?

January 22, 2019 3:27 pm

I’ve asked 1,000s of times for someone to identify a controlled experiment demonstrating that LWIR between 13 and 18 microns can actually warm water I have yet to get an adequate answer. I’ve posted videos of a CO2 laser doing nothing more than etching ice. Would someone with access to a college lab please video a glass of water with a thermometer in it being warmed by a CO2 laser? My bet is the CO2 laser (which is LWIR around 10 microns) won’t warm the water, it will actually cool it through surface evaporation. If LWIR between 13 and 18 microns, which doesn’t penetrate water, can’t warm water, all this discussion is for naught. The marginal W/m^2 of man’s 140 ppm CO2 is a whopping 0.94 W/m^2 (MODTRAN Looking Up From Surface, background is 270 ppm current is 410 ppm). The specific heat of water is the highest of any common substance at 4.186 joules/gm C. It takes a whole lot of energy to warm water, and CO2 simply doesn’t supply that much energy.

John F. Hultquist
Reply to  CO2isLife
January 22, 2019 7:59 pm

“I’ve asked 1,000s of times …”

Doing the same think over, and over . . .
Hmm ?

Reply to  CO2isLife
January 22, 2019 9:14 pm

My understanding too
But I have also read the argument runs its not the CO2 radiating LWIR downwards that warms the oceans.

Rather its the slowing of the rate at which heat is leaving the oceans because of absorption by the increased atmospheric CO 2

Thus this it is argued keeps more heat in the oceans (originating from solar radiation ) than would other wise be in the absence of the increased atmospheric CO2
Any comment on that line of analysis?

Alan Tomalty
Reply to  thomho
January 22, 2019 11:22 pm

Heat leaves the ocean only 3 ways. Through evaporation and conduction and upward IR. CO2 has nothing to do with these processes. Also, the atmosphere doesn’t dump heat into the oceans. NASA tries to say that significant heat leaves by upward LWIR. The only way they make that work mathematically is by having clouds reflecting only 50 % of the DWIR. Thayer Watkins has calculated that clouds are responsible for 85% of the DWIR and they do it reflectively NOT by absorption and emission.

The only ways that the rate of evaporation would slow down is if the atmosphere had a higher humidity or if the winds were less or if the oceans were cooler . None of those 3 things has been observed. Attempts to measure atmospheric water vapour have not shown any appreciable increase. Conduction would slow down if the atmosphere got a lot hotter but the amounts pale in comparison to evaporation which has not shown any difference over the years. As to upward IR the fight is over who is right : Thayer Watkins or NASA. In the analysis below I show that NASA are wrong.


Clouds overwhelm the Downward Infrared Radiation (DWIR) produced by CO2. At night with and without clouds, the temperature difference can be as much as 11C. The amount of warming provided by DWIR from CO2 is negligible but is a real quantity. We give this as the average amount of DWIR due to CO2 and H2O or some other cause of the DWIR. Now we can convert it to a temperature increase and call this Tcdiox.The pyrgeometers assume emission coeff of 1 for CO2. CO2 is NOT a blackbody. Clouds contribute 85% of the DWIR. GHG’s contribute 15%. See the analysis in link. The IR that hits clouds does not get absorbed. Instead it gets reflected. When IR gets absorbed by GHG’s it gets reemitted either on its own or via collisions with N2 and O2. In both cases, the emitted IR is weaker than the absorbed IR. Don’t forget that the IR from reradiated CO2 is emitted in all directions. Therefore a little less than 50% of the absorbed IR by the CO2 gets reemitted downward to the earth surface. Since CO2 is not transitory like clouds or water vapour, it remains well mixed at all times. Therefore since the earth is always giving off IR (probably a maximum at 5 pm everyday), the so called greenhouse effect (not really but the term is always used) is always present and there will always be some backward downward IR from the atmosphere.

When there isn’t clouds, there is still DWIR which causes a slight warming. We have an indication of what this is because of the measured temperature increase of 0.65 from 1950 to 2018. This slight warming is for reasons other than just clouds, therefore it is happening all the time. Therefore in a particular night that has the maximum effect , you have 11 C + Tcdiox. We can put a number to Tcdiox. It may change over the years as CO2 increases in the atmosphere. At the present time with 409 ppm CO2, the global temperature is now 0.65 C higher than it was in 1950, the year when mankind started to put significant amounts of CO2 into the air. So at a maximum Tcdiox = 0.65C. We don’t know the exact cause of Tcdiox whether it is all H2O caused or both H2O and CO2 or the sun or something else but we do know the rate of warming. This analysis will assume that CO2 and H2O are the only possible causes. That assumption will pacify the alarmists because they say there is no other cause worth mentioning. They like to forget about water vapour but in any average local temperature calculation you can’t forget about water vapour unless it is a desert.
A proper calculation of the mean physical temperature of a spherical body requires an explicit integration of the Stefan-Boltzmann equation over the entire planet surface. This means first taking the 4th root of the absorbed solar flux at every point on the planet and then doing the same thing for the outgoing flux at Top of atmosphere from each of these points that you measured from the solar side and subtract each point flux and then turn each point result into a temperature field by integrating over the whole earth and then average the resulting temperature field across the entire globe. This gets around the Holder inequality problem when calculating temperatures from fluxes on a global spherical body. However in this analysis we are simply taking averages applied to one local situation because we are not after the exact effect of CO2 but only its maximum effect.
In any case Tcdiox represents the real temperature increase over last 68 years. You have to add Tcdiox to the overall temp difference of 11 to get the maximum temperature difference of clouds, H2O and CO2 . So the maximum effect of any temperature changes caused by clouds, water vapour, or CO2 on a cloudy night is 11.65C. We will ignore methane and any other GHG except water vapour.

So from the above URL link clouds represent 85% of the total temperature effect , so clouds have a maximum temperature effect of .85 * 11.65 C = 9.90 C. That leaves 1.75 C for the water vapour and CO2. This is split up with 60% for water vapour and 26% for CO2 with the remaining % for methane, ozone ….etc. See the study by Ahilleas Maurellis and Jonathan Tennyson May 2003 in Physics World. Amazingly this is the only study that quantifies the Global warming potential of H20 before any feedback effects. CO2 will have relatively more of an effect in deserts than it will in wet areas but still can never go beyond this 1.75 C . Since the desert areas are 33% of 30% (land vs oceans) = 10% of earth’s surface , then the CO2 has a maximum effect of 10% of 1.75 + 90% of Twet. We define Twet as the CO2 temperature effect of over all the world’s oceans and the non desert areas of land. There is an argument for less IR being radiated from the world’s oceans than from land but we will ignore that for the purpose of maximizing the effect of CO2 to keep the alarmists happy for now. So CO2 has a maximum effect of 0.175 C + (.9 * Twet). So all we have to do is calculate Twet.

Reflected IR from clouds is not weaker. Water vapour is in the air and in clouds. Even without clouds, water vapour is in the air. No one knows the ratio of the amount of water vapour that has now condensed to water/ice in the clouds compared to the total amount of water vapour/H2O in the atmosphere but the ratio can’t be very large. Even though clouds cover on average 60 % of the lower layers of the troposhere, since the troposphere is approximately 8.14 x 10^18 m^3 in volume, the total cloud volume in relation must be small. Certainly not more than 5%. H2O is a GHG. So of the original 15% contribution by GHG’s of the DWIR, we have .15 x .26 =0.039 or 3.9% to account for CO2. Now we have to apply an adjustment factor to account for the fact that some water vapour at any one time is condensed into the clouds. So add 5% onto the 0.039 and we get 0.041 or 4.1 % . CO2 therefore contributes 4.1 % of the DWIR in non deserts. We will neglect the fact that the IR emitted downward from the CO2 is a little weaker than the IR that is reflected by the clouds. Since, as in the above, a cloudy night can make the temperature 11C warmer than a clear sky night, CO2 or Twet contributes a maximum of 0.041 * 1.75 C = 0.07 C.

Therfore Since Twet = 0.07 C we have in the above equation CO2 max effect = 0.175 C + (.9 * 0.07 C ) = ~ 0.238 C. As I said before; this will increase as the level of CO2 increases, but we have had 68 years of heavy fossil fuel burning and this is the absolute maximum of the effect of CO2 on global temperature.
So how would any average global temperature increase by 7C or even 2C, if the maximum temperature warming effect of CO2 today from DWIR is only 0.238 C? This means that the effect of clouds = 85%, the effect of water vapour = 13 % and the effect of CO2 = 2 %.
Sure, if we quadruple the CO2 in the air which at the present rate of increase would take 278 years, we would increase the effect of CO2 (if it is a linear effect) to 4 X 0.238 C = 0.952 C .

If the cloud effect was 50% as NASA says it is, then the numbers would be

Even if the cloud effect was 0 for DWIR, the maximum that CO2 could be is 10%(desert) of 0.65 + (90% of Twet2) = 0.065 C + (90% *twet2)
twet2 = .26( see 1st analysis above) * 0.585 C (difference between 0.65 and the amount of temperature effect for CO2 for desert) = 0.1521 C therefore Max CO2 = 0.065 C + (0.1521 * .9) = 0.2 C ((which is about 84% of above figure of 0.238 C. The 0.2 C was calculated by assuming as above that on average H20 is 60% of greenhouse effect and CO2 is 26% of GHG effect and that the whole change of 0.65 C from 1950 to 2018 is because of either CO2 or water vapour. We are disregarding methane and ozone. So in effect, the above analysis regarding clouds gave too much maximum effect to CO2. The reason is that you simply take the temperature change from 1950 to 2018 disregarding clouds, since the water vapour has 60% of the greenhouse effect and CO2 has 26%. If you integrate the absorption flux across the IR spectrum despite the fact that there are 25 times more molecules than CO2 by volume, you get 60% for H20 and 26% for CO2 as their GHG effects. See the study by Ahilleas Maurellis and Jonathan Tennyson May 2003 in Physics World. CO2 can never have as much effect as H20 until we get to 2.3x the amount of CO2 in the atmosphere than there is now.
NASA says clouds have only a 50% effect on DWIR. So let us do that analysis.

So according to NASA clouds have a maximum temperature effect of .5 * 11.65 C = 5.825 C. That leaves 5.825 C for the water vapour and CO2. This is split up with 60% for water vapour and 26% for CO2 with the remaining % for methane, ozone ….etc. As per the above. Again since the desert areas are 33% of 30% (land vs oceans) = 10% of earth’s surface , then the CO2 has a maximum effect of (10% of 5.825 C) + 90% of TwetNASA. We define TwetNASA as the CO2 temperature effect of over all the world’s oceans and the non desert areas of land. So CO2 has a maximum effect of 0.5825 C + (.9 * TwetNASA). So all we have to do is calculate TwetNASA.

Since as before we give the total cloud volume in relation to the whole atmosphere as not more than 5%. H2O is a GHG. So of the original 50% contribution by GHG’s of the DWIR, we have .5 x .26 =0.13 or 13 % to account for CO2. Now we have to apply an adjustment factor to account for the fact that some water vapour at any one time is condensed into the clouds. So add 5% onto the 0.13 and we get 0.1365 or 13.65 % . CO2 therefore contributes 13.65 % of the DWIR in non deserts. As before, we will neglect the fact that the IR emitted downward from the CO2 is a little weaker than the IR that is reflected by the clouds. Since, as in the above, a cloudy night can make the temperature 11C warmer than a clear sky night, CO2 or TwetNASA contributes a maximum of 0.1365 * 5.825 C = ~0.795 C.

Therfore Since TwetNASA = 0.795 C we have in the above equation CO2 max effect = 0.5825 C + (.9 * 0.795 C ) = ~ 1.3 C. Now this is double the amount of actual global warming in the last 68 years, so since CO2 would not have more of an effect on a cloudy night versus a noncloudy night, the maximum effect could not be greater than the effect calculated, above, when not considering clouds. So clearly, NASA cannot be correct.

I fail to understand how climate scientists could get away with saying that water vapour doesnt matter because it is transitory. In fact the alarmist theory needs a positive forcing of water vapour to achieve CAGW heat effects. Since there is widespread disagreement on any increase in H2O in the atmosphere in the last 68 years, there hasn’t been any positive forcing so far. Therefore; the hypothesis is; that main stream climate science theory of net CO2 increases in the atmosphere has major or catastrophic consequences for heating the atmosphere and the null hypothesis says it doesn’t have major or catastrophic consequences for heating the atmosphere. Therefore we must conclude that we cannot reject the null hypothesis that main stream climate science theory of net CO2 increases in the atmosphere does not have major or catastrophic consequences for heating the atmosphere. In fact the evidence and the physics of the atmosphere shows that if we rejected the null hypothesis, we would be rejecting most of radiative atmospheric physics as we know it. So in the end, the IPCC conclusion of mankind increasing net CO2 into the atmosphere, causing major or catastrophic warming of the atmosphere; is junk science.

Anthony Banton
Reply to  Alan Tomalty
January 23, 2019 3:30 am

“Heat leaves the ocean only 3 ways. Through evaporation and conduction and upward IR. CO2 has nothing to do with these processes. ”

It has everything to do with these processes…..

“Our findings provide an explanation of the mechanism for retaining upper ocean heat content as the incident IR radiation increases. The absorption of increased longwave has been deduced to compress vertically the curvature of the TSL, with a higher gradient forming close to the interface and a lower gradient at subskin depths. The smaller vertical gradient at subskin depths impedes the transfer of heat from the mixed layer into the TSL. Because the heat sink at the interface does not change measurably on the scales of our individual measurements, this means that less heat from the mixed layer contributes to the loss of heat at the interface. This analysis was based on the immediate changes of the TSL to the heat fluxes due to the instantaneous response of the TSL. Greater downwelling infrared forcing would alter the upper ocean heat budget by adjusting the TSL such that more heat beneath the TSL, resulting from the absorption of solar radiation, is retained. This thus provides an explanation for the indirect heating of the ocean by increasing levels of incident infrared radiation and the observed increase in upper ocean heat content.”

Alan Tomalty
Reply to  Anthony Banton
January 23, 2019 7:35 am

Anthony you left off the final 2 sentences in the report.

“Attempts to relate directly the curvature of vertical temperature gradient in the TSL and EM skin layer, as developed by Wong and Minnett (2016a, 2016b), to changes in the incident IR radiation did not produce a convincing dependence, at least on the time scales of our measurements. Revealing such a relationship will require more sensitive instruments than are currently available.”

This preposterous hypothesis is the key underpinning of the report. If the curvature of the thermal skin layer (TSL) is NOT compressed vertically , then the imaginary smaller vertical gradient will NOT impede the transfer of heat from the mixed layer into the TSL. If this doesn’t happen then there is no basis for saying that it provides “an explanation of the mechanism for retaining upper ocean heat content as the incident IR radiation increases.”

Furthermore the researchers in section 3.2 state

“Thus, we have exploited the variability of clouds overhead during sequences of M‐AERI measurements as a surrogate for an increase in atmospheric IR emission due to rising levels of GHG. ”

That statement would be acceptable if clouds acted exactly the same way that CO2 does with respect to DWIR. However they do NOT. Clouds reflect the upward IR. They don’t absorb the upward IR. Whereas CO2 absorbs and emits which makes the DWIR much weaker than the reflected IR from clouds. The researchers ignore this.

Reply to  Anthony Banton
January 23, 2019 3:28 pm

Once again, that can be tested in a lab. Do they not do basic experiments in the field of climate “science?” What kind of “science” doesn’t do experiments? Someone, please film two classes of warmed water. One that is the control and one that has a CO2 laser pointed on its surface. Record the rate of temperature change. Does the CO2 lasered glass cool at a slower or faster rate? Why haven’t the “experts” done that basic experiment?

James Clarke
Reply to  thomho
January 22, 2019 11:55 pm

The process of slowing the rate of heat leaving the oceans still requires a warming of the atmosphere first. The idea is that the oceans, on average, are warmer than the near surface air, although I have no way of knowing that this is true. Nonetheless, the larger the delta T is between the warm water and the cooler near surface air, the more the water will give up it’s heat energy to that air. The smaller the delta T, the less efficient the energy transfer. In other words, the rate of energy lose from the oceans to the atmosphere decreases as the near surface air temperatures warm closer to the near surface water temperatures. If the air is warming, the assumption is that the oceans are losing less heat to the atmosphere, all else being equal.

The problem is that the air temperature is not warming, except when the ocean coughs up a tremendous amount of heat during strong El Ninos. Then the air gets warmer, which, if the mechanism is correct, causes less heat to escape from the oceans, making the oceans warmer! They are arguing that the warmer air makes warmer oceans, but we don’t observe warmer air until the ocean warms it with a strong El Nino!

The effect cannot be the source of the cause!

Reply to  James Clarke
January 23, 2019 2:37 am

The problem is that the air temperature is not warming, except when the ocean coughs up a tremendous amount of heat during strong El Ninos.

It also absorbs an enormous amount of heat during la Ninas. Over time, ENSO is in balance (being an oscillation). If you sum the annual averages in the NOAA ENSO index, the trend since 1950 is flat (actually slightly negative):

James Clarke
Reply to  DWR54
January 23, 2019 5:37 am


I am not sure what your point is, but the base period for calculating ENSO index numbers is adjusted every 5 years: “Due to a significant warming trend in the Niño-3.4 region since 1950, El Niño and La Niña episodes that are defined by a single fixed 30-year base period (e.g. 1971-2000) are increasingly incorporating longer-term trends that do not reflect interannual ENSO variability. In order to remove this warming trend, CPC is adopting a new strategy to update the base period.”

So the Nino 3.4 region is about 0.4 degrees C warmer today than it was in 1950. This warming of the Pacific Ocean surface water appears to be driving the atmospheric warming, not the other way around. Increasing CO2 has been constant, but atmospheric warming only happens with super El Nino events. The proposed mechanism for CO2 warming of the oceans requires the atmosphere to warm first, in order to reduce the amount of energy escaping the oceans. The alleged cause (atmospheric warming) is being blamed for the alleged effect (ocean warming). But in reality, the cause is clearly ocean warming, and the effect is atmospheric warming.

Why is the Nino 3.4 region 0.4 degrees warmer today than it was in 1950? Solar cycles? Inherent ocean cycles? I do not know, but it is clearly not due to increasing atmospheric CO2! The amount of atmospheric warming taking place between super El Nino events is negligible, and shows up as a series of ‘pauses’, or even declines, in the air temperature records.

The argument that a warmer atmosphere (from increasing CO2) is warming the oceans is like arguing that the egg caused the chicken that laid it!

Reply to  DWR54
January 23, 2019 12:02 pm

James Clarke,

As you said yourself, ‘the effect cannot be the source of the cause’. To my knowledge the only people claiming that it can are not climate scientists. Bob Tisdale, who appears to believe that the ocean can heat both itself and the atmosphere simultaneously without the need for any extra outside energy input, being a good case in point.

Oscillations like ENSO cannot add heat to a system, otherwise they wouldn’t be oscillations. They would be forcings.

The reason for the 5-year NOAA ENSO index adjustment is, as they state, and as you quote, due to the “significant warming trend in the Niño-3.4 region since 1950…”. They are not saying here that the ocean is warming itself. They are saying there is clear background warming trend, over and above the normal ups and downs caused by ENSO.

If they ignored this, then the ‘departure from average’ would be meaningless, since ‘average’ is constantly getting warmer; not because of ENSO but because of background warming.

You say:

The amount of atmospheric warming taking place between super El Nino events is negligible, and shows up as a series of ‘pauses’, or even declines, in the air temperature records.

That simply isn’t the case. The rate of warming during el Nino, la Nina and ENSO neutral years is statistically insignificant; they all show warming at a rate of ~0.13 to 0.14 C per decade since 1950 using the NOAA data.

You can check this yourself by using the NOAA ENSO index (linked to above) and the NOAA global surface temperature data. I used annually averaged data for both to make this chart, which shows NOAA global temperatures based on average ENSO conditions for each respective year (note, there is probably an offset required because it takes about 3 months for ENSO conditions to influence surface temperatures, but it makes little difference to the overall outcome):

The idea that warming only occurs during or becaus eof el Nino periods is a myth.

Reply to  DWR54
January 23, 2019 3:33 pm

Anthropogenic CO2 adds 0.94W/m^2 to the system 24×7, sunlight adds 1,050W/m^2 12×7. A single cloudy hour of the day can erase the contribution of months worth of CO2. A single El Nino removes 10s if not 100s of years of CO2’s contribution. The rate of energy replacement by CO2 is simply way way way too slow to replace the enormous amounts of energy lost through El Ninos. Simply do the math. Rita and Kitrina reduced the Gulf temperature by a full 1 degree C. Simply calculate out how long it takes 0.94W/m^2 to warm a m^3 of water by 1 degree C.

Reply to  thomho
January 23, 2019 8:26 am

CO2 and H2O absorb the same wavelengths. H20 saturates the air immediately above the oceans. Using MODTRAN you can see that CO2 immediately above the oceans doesn’t impact the W/m^2 at all if you include H20. Water set at 1 the W/m^2 of Anthropogenic CO2 is 0.94W/m^2. Add in 4% H2O and it shoots up to 4.08 W/m^2. Water, not CO2 is slowing the warming.

Rud Istvan
Reply to  CO2isLife
January 24, 2019 2:46 pm

CO2isLife, you are asking an inappropriate question.
IR ‘Backradiation’ cannot warm the ocean, physics you surely know (or should know). Your question mistates deliberately or unfortunately misunderstands the GHE.
ALL warming comes from incoming solar radiation. All cooling comes from a thus warmed Earth radiating IR to space (with a CMB determined temperature of about 2.8K).
The GHE is NOT ever a direct warming. It an absence of sufficient atmospheric cooling caused by IR impeding trace atmospheric gasses, the most omportant being water vapor, which results in an indirect warming from absence of sufficient cooling.

Richard molineux
Reply to  Rud Istvan
January 24, 2019 3:07 pm

“IR ‘Backradiation’ cannot warm the ocean”


The ocean can emit IR. If a substance can emit IR, it can also absorb IR.

Incoming IR to the ocean will heat it.

January 22, 2019 4:31 pm

One thing that most people agree about, is that warm water expands .

So if indeed the Oceans are warming, plus the usual “Far more than we thought”stuff, why no indication that the sea level is rising more than the slow increase from the ice ages in the past.

Also of course allow for the land dropping too. “That should also get the “Far worse than we thought” sarc.


Anthony Banton
Reply to  Michael
January 23, 2019 3:08 am

“So if indeed the Oceans are warming, plus the usual “Far more than we thought”stuff, why no indication that the sea level is rising more than the slow increase from the ice ages in the past.”

there is …. but you wont find it on here unless you go to the links people like me post……

“Climate-change–driven accelerated sea-level rise detected in the altimeter era”
R. S. Nerem, B. D. Beckley, J. T. Fasullo, B. D. Hamlington, D. Masters, and G. T. Mitchum
PNAS February 27, 2018 115 (9) 2022-2025;
Published ahead of print February 12, 2018

comment image

“Fig. 1.
GMSL from the adjusted processing of ref. 15 (blue) and after removing an estimate for the impacts of the eruption of Mount Pinatubo (12) (red), and after also removing the influence of ENSO (green), fit with a quadratic (black). The acceleration (0.084 mm/y2) is twice the quadratic coefficient.”

Total Sea Level
1993 – 2017 3.1 0.4 Cazenave et al., 2018 Satellite altimetry
1901 – 1990 1.1 to 1.9 0.3 Dangendorf et al., 2017 Tide gauge reconstruction
1993 – 2010 2.8 to 3.1 0.7 to 1.4 Cazenave et al., 2018 Tide gauge reconstruction

Reply to  Anthony Banton
January 23, 2019 8:03 am

Unfortunately that acceleration only turns up after “adjusted processing”. It isn’t noticeable in the real World:

375 long-term tidal gauge records. You are welcome to look around for those that show acceleration. Good Luck!

Lurker Pete
January 22, 2019 4:38 pm

“This does not impact the message in the published Science article. ”

Should science papers even have a “message” ?

Jim Steele
January 22, 2019 7:31 pm


Can you comment on the Heimbach and Wundsch papers and the Purkey paper. Papers always claiming the deep ocean is warming always cite Purkey and never Heimbach

Heimbach 2014 “Bidecadal Thermal Changes in the Abyssal Ocean” states “About 52% of the ocean lies below 2000m and about 18% below 3600 m. By defining a volume as having been ‘‘probed’’ if at least one CTD station existed within a roughly 60 x 60 km2 box in the interval 1992–2011, a minimal measure of sampling can be obtained. Thus, about 1/ 3 (11%of the total volume) of water below 2000 m was sampled during that time. Of the 16% lying below 3600m, about 17% was measured. As a consequence of this under-sampling, even with the improvements in the last 20 yr, many papers have been published that simply assume no significant changes have taken place in the deep ocean over the historical period.” In contrast Heimback states “Parts of the deeper ocean, below 3600 m, show cooling.” They also warn that researchers should not assume the oceans were in equilibrium with the surface climate before CO2 started rising. They assert the oceans are still equilibrating to past warm periods.

In contrast many authors who assert the deep ocean is gaining heat, they always cite Purkey 2013 but almost never mention Heimbach and Wunsch’s claim that many parts of the deep ocean are still cooling, releasing heat absorbed centuries earlier.

Nic Lewis
January 23, 2019 2:21 am

Jim Steele
“Can you comment on the Heimbach and Wundsch papers and the Purkey paper.”

I agree with what you say. It is far from clear that the deep (abyssal) ocean is gaining heat as claimed by Purkey & Johnson 2010 and, more recently, Desbruyeres et al 2016. As well as the Wunsch and Heimbach 2014 paper, the Gebbie and Huybers 2019 paper “The Little Ice Age and 20th-century deep Pacific cooling” is also relevant. Interstingly, it shows strong total ocean heat uptake in the 2nd half of the 19th century, which would push down historical period energy budget estimates of climate sensitivity.

January 23, 2019 10:54 am

Don’t we need to know just how fast thought is accelerating before we do the comparison?

Schrodinger's Cat
January 23, 2019 11:13 am

By what mechanism does global warming heat the oceans?

Solar (visible) radiation does penetrate the sea to a depth dependent on various factors including angle of incidence and turbidity. Dissipation of this heat is mainly by current. Convection is low because the warmer layers are already nearer the surface. Conduction is limited because of the striation and radiation is not possible because the sea is opaque to infra red.

Down welling infra red cannot penetrate the oceans but can warm the surface layer leading mainly to evaporation, which in turn requires latent heat which leaves the surface cooler.

All of these factors help to explain why oceans can contain heat for decades or centuries. They do not explain how an atmospheric warming mechanism can heat the oceans. our oceans warm the atmosphere, not the other way around. Water has about 4000 times the heat capacity of the air. The atmosphere heating the sea is rather like trying to heat a bathtub of water with a hair dryer.

January 23, 2019 3:25 pm

My understanding as to how the deep Oceans receive either heat or less heat, i.e. cooler water, that starts at the Equator , then goes either North or South from there up to t the Poles. T hen as its now getting colder it sinks, and joins the hundreds of years movement of water in the deep.

So any change in the deeper part of the Oceans all occurred long ago, before the puny efforts by us to perhaps change the climate just a little bit.


January 23, 2019 4:00 pm

Can someone please tell me what reasonable Water Vapor Scales are for MODTRAN? Just what does 1 mean? What would I enter for a very humid day? What is the max water vapor scale that is reasonable for the atmosphere? What value would you use for a desert? Any insight would be appreciated.

January 24, 2019 3:49 am

“it highlights the uncertainty in actual trends and their use to depict changes.” But we’ll do it anyway

The use of Levitus imports strong uncertainty, because his historical data were based on ship-gathered measurements with large and unquantifiable errors. It demonstrates how uncertainty is carried forward into subsequent studies as scientific fact.
Dr Robert Stevenson,

I believe the Cheng paper was a PNAS paper, Cheng says “The conclusions in our Perspective remain sound.”

PNAS describe Perspectives papers as follows:
“Perspectives present a viewpoint on an important area of research. Perspectives focus on a specific field or subfield within a larger discipline and discuss current advances and future directions. Perspectives are of broad interest to nonspecialists and may add personal insight to a field, but should be balanced and objective.

Perspectives are written only at the invitation of the Editorial Board and evaluated for publication using the same process as Direct Submissions.”

So, this was scientific opinion, not scientific fact, but the PNAS imprimature gives it the “Scientists Say” motif, so beloved of the MSM.

Direct Submissions
“Authors must recommend three appropriate Editorial Board members, three NAS members who are expert in the paper’s scientific area, and five qualified reviewers. The Board may choose someone who is or is not on that list or may reject the paper without further review. Authors are encouraged to indicate in their cover letter why their suggested editors are qualified to handle the paper.

As an example, John Schellnhuber is a member editor in this area:

So also is Carl Folke of the Stockholm Resilience Centre, a co-author with Schellnhuber of last year’s “Hothouse Earth” paper, (Steffen et al), also a PNAS Perspective submission.

One could question the validity of authors being editors of the field in which they are submitting papers, but Hothouse Earth was submitted as Steffen et al, not Schellnhuber et al.

I suspect not many contrary papers get past this editorial board. “More than 50% of Direct Submissions are declined by the Editorial Board without additional review, within 2 weeks on average.”

At the moment, scary papers are needed to keep the flame burning and they are almost guaranteed publication by PNAS, giving them the scientific authority suitable to set the NYT and the rest, in motion.

Having been accepted by PNAS, authors then feel their work is validated.

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