A potential AGW buster, attributing decadal temperature variation largely to internal oceanic effects, ENSO and over the longer term the 1976 Great Pacific Climate Shift, as we did here, is a new paper by Australian John McLean, with New Zealander Chris de Freitas, and Australian ex-pat Kiwi Bob Carter.
That mean global tropospheric temperature has for the last 50 years fallen and risen in close accord with the SOI of 5–7 months earlier shows the potential of natural forcing mechanisms to account for most of the temperature variation.
While the bottom line of this paper is that the change in SOI accounts for 72% of the variance in global temperature for the 29-year-long MSU record and 68% of the variance in global temperature for the longer 50-year RATPAC record, I think the claim of a longer term temperature effect could have been better supported. They stated:
Lean and Rind [2008] stated that anthropogenic warming is more pronounced between 45°S and 50°N and that no natural process can account for the overall warming trend in global surface temperature. We have shown here that ENSO and the 1976 Great Pacific Climate Shift can account for a large part of the overall warming and the temperature variation in tropical regions.
However, the assertion comes down to Figure 4 where they identify that the mean of the SOI (and temperature) seems to change at 1976. This model is not identified rigorously with any analysis, but is stated as an observation in the text.
For the 30 years prior to the 1976 shift (i.e., 1946 – 1975) the SOI averaged +1.93 but in the 30 years after 1976 (i.e., 1977 – 2006) the average was -3.06, which represents a shift from a La Nina inclination to an El Nino inclination. The standard deviations for the two periods were 9.48 and 10.40 on monthly SOI averages, and 6.56 and 6.35 on calendar year averages, which indicates consistent variation about a new average value. … From 1959 to 1975 the RATPAC LTT averaged -0.191°C and from 1977 to 1993 it averaged +0.122°C. The standard deviations on the seasonal data were 0.193° and 0.163 C°, and on monthly data 0.162°C and 0.146°C. We have already illustrated the close relationship between SOI and GTTA, but this descrip- tion of the respective changes before and after the Great Pacific Climate Shift indicates a stepwise shift in the base values of each factor but otherwise relatively consistent ranges of variation.
Break tests on both SOI and global temperature indicating the date 1976, and finding of a 7 month lead in the position of the break for SOI over global temperature would have lent more support to this (crucial) claim. As it is, the finding of high frequency correlation between SOI and GT is not as important to the AGW debate, as is the finding of a low frequency (ie. step change) in SOI leading (and hence causing) the change in temperatures.
It can also be seen in Figure 4 that the slope of temperature is upward while the SOI is constant (but higher) after 1976. This would tend to support Bob Tisdale’s hypothesis that recent warming since 1976 can be attributed to a gradual accumulation of heat, due to higher frequency of El Nino events. He has dug up a long-recognized, but little studied mechanism of re-emergence to explain it.
Landshape 
David: Thanks for the link to my post “The Reemergence Mechanism”.
You wrote, “This would tend to support Bob Tisdale’s hypothesis that recent warming since 1976 can be attributed to a gradual accumulation of heat, due to higher frequency of El Nino events.”
Actually, as you noted on an earlier thread, I’ve replicated the Global Surface Temperature record from about 1910 to present with only natural forcings (ENSO, solar, and volcanic aerosols). The post is here:
http://bobtisdale.blogspot.com/2009/01/reproducing-global-temperature.html
My favorite part of that post is finding what appears to be a discontinuity in one of the datasets (NINO3.4 SST anomalies or HADCRUT3GL) prior to 1910.
David: Thanks for the link to my post “The Reemergence Mechanism”. You wrote, “This would tend to support Bob Tisdale’s hypothesis that recent warming since 1976 can be attributed to a gradual accumulation of heat, due to higher frequency of El Nino events.”Actually, as you noted on an earlier thread, I've replicated the Global Surface Temperature record from about 1910 to present with only natural forcings (ENSO, solar, and volcanic aerosols). The post is here:http://bobtisdale.blogspot.com/2009/01/reproduc…My favorite part of that post is finding what appears to be a discontinuity in one of the datasets (NINO3.4 SST anomalies or HADCRUT3GL) prior to 1910.
Is there a link to a version of this paper not behind a paywall?
Is there a link to a version of this paper not behind a paywall?
OK, it wasn’t such a big paywall, so I read it. All they have done is show that fluctuations in temp correlate with ENSO and volcanoes, which is no surprise. As DS suggests, this does not pin down an explanation for a trend. And as Tamino points out, the way they have done it makes that impossible. They detrended the data before they started.
OK, it wasn't such a big paywall, so I read it. All they have done is show that fluctuations in temp correlate with ENSO and volcanoes, which is no surprise. As DS suggests, this does not pin down an explanation for a trend. And as Tamino points out, the way they have done it makes that impossible. They detrended the data before they started.
Hi again Bob; I’ll try to be clearer than I was in a prior thread because this idea of ENSO causing or not causing trends is the gist of Tamino’s critique of the McLean paper. In your Reemergence post you say;
“El Nino events are not followed by La Nina events of equal and opposite magnitude. In fact, there are epochs when the frequency and magnitude of El Nino events greatly outweigh those of La Nina events. During those periods, the global oceans would integrate the effects of a predominance of El Nino events. This should appear as a gradual rise in global SST anomalies. The opposite would hold true for periods when the frequency and magnitude of La Nina events outweigh those of El Nino events. The result of the global oceans integrating the effects of ENSO during a period of when La Nina events dominate should appear as a gradual decrease in global SST anomalies”
I conclude from this that 3 possible scenarios are possible;
1 In an El Nino dominated period the temperature will increase
2 In a La Nina dominated period the temperature will decline
3 In a period where El Nino and La Nina are equivalent the temperature will be flat.
That is, over any nominated period the temperature will go up, down or remain constant; but the variable here is the length of the period; heat is not being created but redistributed. This is the oscillation effect with no true trend. The reemergence mechanism will intensify an El Nino period and mitigate a La Nina period.
David’s break paper is consistent with this. In the Australian circumstance [Figure 1] the flat periods before and after the break are scenario 3 situations. Globally [Figure 2] the slightly rising period from 1978 to 1998 is a scenario 1 while post 1998 is a scenario 2. In all scenarios there is no AGW effect because the ENSO effect occurs at the break with the reemergence effect [or lack thereof] creating the post break ‘trend’ [or lack thereof].
If this is plausible can someone go and tell Tamino because his gloating is not pleasant.
The problem with this, even if it could be made more quantitative, it that it does not accord with the flow of heat. If the atmosphere is being heated by a string of el Nino’s, then the ocean would cool. But in the warming period from 1975 on, the ocean warmed too.
Your argument missed many fundimental properties of El Nino events. Significant El Nino events shift SUBSURFACE water from the Pacific Warm Pool to the SURFACE of the eastern equatiorial Pacific where it warms the atmosphere. The tropical Pacific would obviously lose heat in this part of the process. But on the other hand, during the El Nino, cloud cover shifts eastward, away from the Pacific Warm Pool. For example, Downwelling Shortwave Radiation over the Pacific Warm Pool increased 25watts/sq meter during the 1997/98 El Nino. Yes, twenty-five watts/sq meter. This obviously causes heat to be gained there. SST and depth-averaged temperature of the Pacific Warm Pool still dropped, but without that additional solar irradiance, those temperatures would have dropped more. The end result, as far as I can tell, is that El Nino events not only redistribute heat from the tropics to the mid-to-high latitudes, they also add heat to the tropics.
Then what you’re saying is that the source of heat was not the el Nino’s, but enhanced surface insolation. This in turn is saying that, in global terms, Earth’s albedo was reduced. Cloud albedo reduction is certainly a debated possible cause of warming (eg Palle), but not an established one.
I’m trying to understand (qualitatively) your comment.
My crude understanding of what you said is :
1) that El Nino moves warm water to the surface of the E. Pacific. Cloud cover over the E. Pacific increases in response to this warm surface water, retaining this heat more than would be without cloud cover.
2) Meanwhile, cold water has surfaced in W. Pacific, resulting in less cloud cover, and that this increased shortwave radiation reaching the ocean surface by 25W/sq meter.
3) You didn’t state it explicitly, but apparently the combination 1 and 2 mean more total energy absorbed over the entire tropical Pacific zone than during non-El Nino times.
I know that this may be a further simplification of an already simplified explanation, but as a novice in the climate field I’m still trying to get oriented.
———————-
It seems that part of your description is an assumption (observation?) that cloud cover increases in E. Pacific during an El Nino event. That seems to be opposite of the recent paper discussed at http://wattsupwiththat.com/2009/07/25/july-24th-issue-of-science-study-shows-clouds-may-exacerbate-global-warming/#more-9573
Your comment over in that thread included “During El Nino events, the cloud cover and precipitation follow the warm water from the Pacific Warm Pool to the Central and Eastern Equatorial Pacific.”
Is there something unusual in this situation that causes cloud cover and precipitation to follow the warm water, or would you expect that in general warm water would have higher cloud cover?
Hi again Bob; I'll try to be clearer than I was in a prior thread because this idea of ENSO causing or not causing trends is the gist of Tamino's critique of the McLean paper. In your Reemergence post you say;”El Nino events are not followed by La Nina events of equal and opposite magnitude. In fact, there are epochs when the frequency and magnitude of El Nino events greatly outweigh those of La Nina events. During those periods, the global oceans would integrate the effects of a predominance of El Nino events. This should appear as a gradual rise in global SST anomalies. The opposite would hold true for periods when the frequency and magnitude of La Nina events outweigh those of El Nino events. The result of the global oceans integrating the effects of ENSO during a period of when La Nina events dominate should appear as a gradual decrease in global SST anomalies”I conclude from this that 3 possible scenarios are possible;1 In an El Nino dominated period the temperature will increase2 In a La Nina dominated period the temperature will decline3 In a period where El Nino and La Nina are equivalent the temperature will be flat.That is, over any nominated period the temperature will go up, down or remain constant; but the variable here is the length of the period; heat is not being created but redistributed. This is the oscillation effect with no true trend. The reemergence mechanism will intensify an El Nino period and mitigate a La Nina period.David's break paper is consistent with this. In the Australian circumstance [Figure 1] the flat periods before and after the break are scenario 3 situations. Globally [Figure 2] the slightly rising period from 1978 to 1998 is a scenario 1 while post 1998 is a scenario 2. In all scenarios there is no AGW effect because the ENSO effect occurs at the break with the reemergence effect [or lack thereof] creating the post break 'trend' [or lack thereof].If this is plausible can someone go and tell Tamino because his gloating is not pleasant.
The problem with this, even if it could be made more quantitative, it that it does not accord with the flow of heat. If the atmosphere is being heated by a string of el Nino's, then the ocean would cool. But in the warming period from 1975 on, the ocean warmed too.
No, I disgree Nick; up to 2002-2003 and the changeover from the XBTs to the ARGO OHC measurement was shallow and would have reflected the warmer SST and immediate depths consistent with the El Nino; if anything the warmer SSTs and measurement of OHC confirm the theory. The cherry on top is the recent decline in OHC correlating with the -ve PDO.
No, there is plenty of evidence about overall ocean heat content during this period (1976- ). Sea level is a pretty good proxy. Anyway, Levitus is authoritative, and he demonstrates warming of the top 3000m. So the warming of the surface certainly isn’t coming from the ocean.
Comparing the three OHC datasets illustrated in Levitus et al (2009), the sudden rise in 2003 in the Levitus OHC makes them the outlier.
To me Domingues appears to represent reality, regardless of whether or not you include the 1958 spike. Look at the data after 1960. It declines until 1976/77, then increase from there.
That’s consistent with the ocean responding to surface temperature. It’s the opposite of what you’d expect if the ocean is passing heat to the surface.
Nick, I’m not too sure what you meant by “It’s the opposite of what you’d expect if the ocean is passing heat to the surface.” The sea surface is included in the calculation of OHC.
What I mean is that surface temps went down, until 1976, then rose. OHC did the same. That’s consistent with a downward flux responding to surface temp. If it was the ocean exchanging heat with the atmosphere that caused the air cooling and then heating, then the ocean should have gained heat to 1976, then cooled as the heat passed (via ENSO) to the air.
Now I know you said that clouds might have a counter effect. All I’m saying is that they would have to turn the heat flow around completely. And I don’t think there’s evidence of that much cloud effect.
No, I disgree Nick; up to 2002-2003 and the changeover from the XBTs to the ARGO OHC measurement was shallow and would have reflected the warmer SST and immediate depths consistent with the El Nino; if anything the warmer SSTs and measurement of OHC confirm the theory. The cherry on top is the recent decline in OHC correlating with the -ve PDO.
No, there is plenty of evidence about overall ocean heat content during this period (1976- ). Sea level is a pretty good proxy. Anyway, Levitus is authoritative, and he demonstrates warming of the top 3000m. So the warming of the surface certainly isn't coming from the ocean.
Levitus authoritative? The NODC graph for 1955 to date shows less OHC increase than Figure 4 of the Levitus paper which shows an increase of 69% in the OHC of the world’s oceans;
http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/
In the NODC graph the period from 2002-2003, which is over 50% of the OHC increase over the whole period, is arguably an artifact of the transition from the XBT to the ARGO devices. Frankly, the 69% figure in the Levitus paper must be taken with several grains of salt.
Less, maybe, but not negative. Bob’s explanation above, which acknowledges ocean warming, makes more sense.
Why doesn’t it make sense?
Sorry, I misread your comment.
Levitus authoritative? The NODC graph for 1955 to date shows less OHC increase than Figure 4 of the Levitus paper which shows an increase of 69% in the OHC of the world's oceans;http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/In the NODC graph the period from 2002-2003, which is over 50% of the OHC increase over the whole period, is arguably an artifact of the transition from the XBT to the ARGO devices. Frankly, the 69% figure in the Levitus paper must be taken with several grains of salt.
Cohenite says:
“If this is plausible can someone go and tell Tamino because his gloating is not pleasant.”
I have been banned from Tamino’s because I dared to differ from his polemical view of AGW. Tamino has been caught out a number of times by myself so it is likely he is wrong in his assessment of the McClean et. al. paper. He only has a small coterie of avid supporters (he has managed to alienate or ban anyone with a thinking brain) and he is largely irrelevant.
Cohenite says:”If this is plausible can someone go and tell Tamino because his gloating is not pleasant.”I have been banned from Tamino's because I dared to differ from his polemical view of AGW. Tamino has been caught out a number of times by myself so it is likely he is wrong in his assessment of the McClean et. al. paper. He only has a small coterie of avid supporters (he has managed to alienate or ban anyone with a thinking brain) and he is largely irrelevant.
Your argument missed many fundimental properties of El Nino events. Significant El Nino events shift SUBSURFACE water from the Pacific Warm Pool to the SURFACE of the eastern equatiorial Pacific where it warms the atmosphere. The tropical Pacific would obviously lose heat in this part of the process. But on the other hand, during the El Nino, cloud cover shifts eastward, away from the Pacific Warm Pool. For example, Downwelling Shortwave Radiation over the Pacific Warm Pool increased 25watts/sq meter during the 1997/98 El Nino. Yes, twenty-five watts/sq meter. This obviously causes heat to be gained there. SST and depth-averaged temperature of the Pacific Warm Pool still dropped, but without that additional solar irradiance, those temperatures would have dropped more. The end result, as far as I can tell, is that El Nino events not only redistribute heat from the tropics to the mid-to-high latitudes, they also add heat to the tropics.
Then what you're saying is that the source of heat was not the el Nino's, but enhanced surface insolation. This in turn is saying that, in global terms, Earth's albedo was reduced. Cloud albedo reduction is certainly a debated possible cause of warming (eg Palle), but not an established one.
Less, maybe, but not negative. Bob's explanation above, which acknowledges ocean warming, makes more sense.
“Less, maybe, but not negative”; well that’s my point Nick; the earlier Levitus is outside the ball-park or should I say cricket field; the new Levitus paper uses the NODC graph for OHC and this shows a decline in OHC for the last 4-5 years and the possible artifact for 2002-2003 arguably indicates that OHC increase over the period from 1976, the phase shift coincident with the oceanographic events which Bob describes and are well documented in the literature, is much less than touted by AGW spokespersons notably government spruikers like Will Steffan. The upwelling partial cessation in 1976 and its resumption in 1998 allowed for warm sea surface water to remain at the surface and continue with the atmospheric heating; Bob’s comments about cloud movements and the remergence mechanism would have acerbated that warming; given the problematic nature of OHC measurement prior to 2002 I don’t see that similtaneous warm oceans and a warm atmosphere should be contradictory.
Coho, you, or someone, needs to present a believable heat flow pattern for “ENSO heating”. The AGW proposition is straightforward. Atmos radiative transfer produces a flux imbalance, which takes the form of 1.6 W/m2 excess downwelling IR. This warms the surface, which produces a partly countervailing upward IR. But most of the heat continues downward into the ocean, which warms as observed.
The ENSO proposition is that heat does not come from above but from movements within the ocean, warming the surface. Now the ocean does not generate heat, and the warmer surface loses heat with greater outgoing IR, so the heat must come from somewhere. And ultimately, from stored heat in the oceans, which must cool. But however you tweak Levitus etc, your never going to have nett cooling since 1976.
Now Bob T says that the extra heat comes from reduced cloud cover associated with ENSO’s. Well, that is an explanation, and like AGW, leads to nett heat flow from above. But reduced cloud albedo has already been examined, not necessarily as a result of ENSO, as a proposition raised by Palle. In most scientists’ views, it has been found wanting, although it’s not entirely dead.
My apologies – failing to read to the end of your post. Is it not the case that the problem with cloud cover changes relate to the uncertainty of net cloud effects?
The increase and decrease in shortwave should heat and cool ocean surfaces.
“Coho, you, or someone, needs to present a believable heat flow pattern for “ENSO heating”.”
If circulation changes deposit heat in places where the infrared opacity is greater or less, there would be changes in temperature from that deposition.
“Less, maybe, but not negative”; well that's my point Nick; the earlier Levitus is outside the ball-park or should I say cricket field; the new Levitus paper uses the NODC graph for OHC and this shows a decline in OHC for the last 4-5 years and the possible artifact for 2002-2003 arguably indicates that OHC increase over the period from 1976, the phase shift coincident with the oceanographic events which Bob describes and are well documented in the literature, is much less than touted by AGW spokespersons notably government spruikers like Will Steffan. The upwelling partial cessation in 1976 and its resumption in 1998 allowed for warm sea surface water to remain at the surface and continue with the atmospheric heating; Bob's comments about cloud movements and the remergence mechanism would have acerbated that warming; given the problematic nature of OHC measurement prior to 2002 I don't see that similtaneous warm oceans and a warm atmosphere should be contradictory.
Coho, you, or someone, needs to present a believable heat flow pattern for “ENSO heating”. The AGW proposition is straightforward. Atmos radiative transfer produces a flux imbalance, which takes the form of 1.6 W/m2 excess downwelling IR. This warms the surface, which produces a partly countervailing upward IR. But most of the heat continues downward into the ocean, which warms as observed.The ENSO proposition is that heat does not come from above but from movements within the ocean, warming the surface. Now the ocean does not generate heat, and the warmer surface loses heat with greater outgoing IR, so the heat must come from somewhere. And ultimately, from stored heat in the oceans, which must cool. But however you tweak Levitus etc, your never going to have nett cooling since 1976.Now Bob T says that the extra heat comes from reduced cloud cover associated with ENSO's. Well, that is an explanation, and like AGW, leads to nett heat flow from above. But reduced cloud albedo has already been examined, not necessarily as a result of ENSO, as a proposition raised by Palle. In most scientists' views, it has been found wanting, although it's not entirely dead.
I agree Nick, and my ideas at this stage are as good as speculation, but I can see how with re-emergence and cloud feedback (ala Spencer) a source region of the ocean could lock into an either cloud-free hot state, or cloudy cool state. The ramp up in global temperatures would result from slow propagation of the current state via ocean currents, with temperature increasing as more areas get filled. This also explains the step transitions in local areas.
I agree Nick, and my ideas at this stage are as good as speculation, but I can see how with re-emergence and cloud feedback (ala Spencer) a source region of the ocean could lock into an either cloud-free hot state, or cloudy cool state. The ramp up in global temperatures would result from slow propagation of the current state via ocean currents, with temperature increasing as more areas get filled. This also explains the step transitions in local areas.
I see that the McLean et. al. paper is receiving a hammering at RC. They call it atrocious. But no one seems to be rushing to the word processing software to write a rebuttal for publication in the literature.
How do you know?
I ‘m curious to know – is there anyone who:
a) has read the paper and
b) is prepared to defend, based on the paper, the authors’ claim that “According to this study little or none of the late 20th century global warming and cooling can be attributed to human activity.”
I agree the conclusions are not justified by the analysis. Which puts it on a par with Rahmstorf et al 2007 (aka we are all going to fry) and Rahmstorf 2007 (aka we are all going to drown). I have done some more analysis and believe the thesis is sound but the way they go there needs work. I might put in a comment along those lines myself.
I have read the paper. McLean made a defence comment at Tamino’s site and received a cursory accusation of being a liar, amongst other things. Grant Foster (Tamino) says that he will be submitting a comment to JGR.
I think it is up to the authors to defend their paper. However, they will never convince committed warmists such as Tamino and the Team (RC). I think their mathematics could have been better audited (although Craig Lohele did advise them).
Thanks for the alert richard. I agree with Tamino that the statements about general trends shouldn’t be in the paper, but I disagree that its the smoothing that increases the correlation, or that the correlation is spurious. I’m not saying more until I write up my comment. As for dishonesty about unsupported claims, I don’t see these guys paying out on Rahmstorf, so who’s the hypocrite.
“I don’t see these guys paying out on Rahmstorf, so who’s the hypocrite.”
That is because Rahmstorf is one of the “team”. I have never seen Tamino or RC pay out on one of their own and I guess I never will.
I see that the McLean et. al. paper is receiving a hammering at RC. They call it atrocious. But no one seems to be rushing to the word processing software to write a rebuttal for publication in the literature.
There is an actual shortwave heating and warming of the oceans due to changing earth albedo over decades. There is an albedo reconstruction post 1998 on the Big Bear Solar Observatory Project Earthshine page that shows a 1% increase in Earth albedo post 1998 – about a 2W/m2 decrease in shortwave radiation at the surface.
There is a bibliography page with a couple of good papers. ISCCP based estimates of cloud cover from 1984 to 1998 are variously reconstructed as an increase in shortwave radiation at the surface of 3 to 4 W/m2.
Significant warming and cooling of the ocean should occur with this shortwave forcing without needing to consider the net effects of clouds. This does suggest a physical explanation for the Pacific Decadal Oscillation and the multidecadal modulation of ENSO – as well as the phasing of other global multi-decadal changes in atmospheric and ocean parameters.
Turbulent currents are produced by water sinking in high latitudes and, indeed, by the spinning of the planet itself. These tend to upwell strongly in certain locations – the north eastern Pacific and in the Humboldt Current especially – but they are suppressed by an ocean wide layer of warm water. A little cooling and cold subsurface currents upwell strongly – a little warming and the currents are suppressed. The 2 to 7 year ENSO pattern is superimposed on the longer cycle in the central Pacific.
I am wondering if the cloud cover changes are associated with the 22 year solar cycle – but in truth would need more than 25 years of data to establish a multi-decadal pattern.
At a minimum the Earth albedo data suggests that clouds need to be treated as more than a feedback and worth exploring as a ‘proximate cause of recent cooling’.
There is a bibliography page with a couple of good papers. ISCCP based estimates of cloud cover from 1984 to 1998 are variously reconstructed as an increase in shortwave radiation at the surface of 3 to 4 W/m2.
Significant warming and cooling of the ocean occurs with the shortwave forcing without needing to consider the net effects of clouds. This does suggest a physical explantion for the Pacific Decadal Oscillation and the multidecadal modulation of ENSO – as well as the phasing of other global multi-decadal phenomenon.
Turbulent currents are produced by water sinking in high latitudes and, indeed, by the spinning of the planet itself. These tend to upwell stongly in certain locations – the north eastern Pacific and in the Humbolt Current especially – but they are suppressed by an ocean wide layer of warm water. A little cooling and cold subsurface currents upwell strongly – a little warming and the currents are suppressed. The 2 to 7 year ENSO pattern is superimposed on the longer cycle in the central Pacific.
I am wondering if the cloud cover changes are asociated with the 22 year solar cycle – but in essence need more than 25 years of data to establish a multi-decadal pattern.
At a minimum the albedo data suggests that cloud need to be treated as more than a feedback.
There is an actual shortwave heating and warming of the oceans due to changing earth albedo over decades. There is an albedo reconstruction post 1998 on the Big Bear Solar Observatory Project Earthshine page that shows a 1% increase in Earth albedo post 1998 – about a 2W/m2 decrease in shortwave radiation at the surface. There is a bibliography page with a couple of good papers. ISCCP based estimates of cloud cover from 1984 to 1998 are variously reconstructed as an increase in shortwave radiation at the surface of 3 to 4 W/m2. Significant warming and cooling of the ocean should occur with this shortwave forcing without needing to consider the net effects of clouds. This does suggest a physical explanation for the Pacific Decadal Oscillation and the multidecadal modulation of ENSO – as well as the phasing of other global multi-decadal changes in atmospheric and ocean parameters. Turbulent currents are produced by water sinking in high latitudes and, indeed, by the spinning of the planet itself. These tend to upwell strongly in certain locations – the north eastern Pacific and in the Humboldt Current especially – but they are suppressed by an ocean wide layer of warm water. A little cooling and cold subsurface currents upwell strongly – a little warming and the currents are suppressed. The 2 to 7 year ENSO pattern is superimposed on the longer cycle in the central Pacific. I am wondering if the cloud cover changes are associated with the 22 year solar cycle – but in truth would need more than 25 years of data to establish a multi-decadal pattern. At a minimum the Earth albedo data suggests that clouds need to be treated as more than a feedback and worth exploring as a ‘proximate cause of recent cooling’. There is a bibliography page with a couple of good papers. ISCCP based estimates of cloud cover from 1984 to 1998 are variously reconstructed as an increase in shortwave radiation at the surface of 3 to 4 W/m2. Significant warming and cooling of the ocean occurs with the shortwave forcing without needing to consider the net effects of clouds. This does suggest a physical explantion for the Pacific Decadal Oscillation and the multidecadal modulation of ENSO – as well as the phasing of other global multi-decadal phenomenon. Turbulent currents are produced by water sinking in high latitudes and, indeed, by the spinning of the planet itself. These tend to upwell stongly in certain locations – the north eastern Pacific and in the Humbolt Current especially – but they are suppressed by an ocean wide layer of warm water. A little cooling and cold subsurface currents upwell strongly – a little warming and the currents are suppressed. The 2 to 7 year ENSO pattern is superimposed on the longer cycle in the central Pacific. I am wondering if the cloud cover changes are asociated with the 22 year solar cycle – but in essence need more than 25 years of data to establish a multi-decadal pattern. At a minimum the albedo data suggests that cloud need to be treated as more than a feedback.
How do you know?I 'm curious to know – is there anyone who:a) has read the paper and b) is prepared to defend, based on the paper, the authors' claim that “According to this study little or none of the late 20th century global warming and cooling can be attributed to human activity.”
My apologies – failing to read to the end of your post. Is it not the case that the problem with cloud cover changes relate to the uncertainty of net cloud effects?The increase and decrease in shortwave should heat and cool ocean surfaces.
I agree the conclusions are not justified by the analysis. Which puts it on a par with Rahmstorf et al 2007 (aka we are all going to fry) and Rahmstorf 2007 (aka we are all going to drown). I have done some more analysis and believe the thesis is sound but the way they go there needs work. I might put in a comment along those lines myself.
Ok Nick I think I’ve got a handle on your [and AGW’s] position; the SST increases through a decrease in upwelling; this correlates [causes/is caused by] with PDO phase shift in 1976 and probably 1998 as David’s break paper shows; the SST increase can warm the atmosphere but this transfer of heat to the atmosphere must logically cool the ocean [since the ocean can’t heat itself] which hasn’t happened; your position is that the IR transfer from the ocean surface is absorbed and back-radiated to the oceans; you rely on the radiative imbalance at TOA to back this up; you prefer this to Bob’s conjecture that cloud cover diminution has enabled greater insolation to maintain the SST; a couple of points;
1 Lindzen’s new paper with Choi shows that “outgoing radiation fluxes increase with the increase in SSTs”; as well “the feedback in ERBE is mostly from shortwave radiation while the feedback in the models is mostly from longwave radiation”.
2 ISCCP data shows low and global cloud cover declining since 1987; ICOADs shows the decline from 1998; so a mixed bag there with ISCCP supporting Bob’s point as Indigo points out.
3 The window or S_T in Miskolczi parlance would play a part here if M’s figure of 62 was true rather than K&T’s 40; on this I’ll simply say that some developments are in the offing about that.
4 If increased SW is coming in concurrent with the increased SST the positive feedback would be there to satisfy both the atmospheric temperature increase and OHC increase.
5 If the above is reasonable than what McLean et al have done is isolate a lag correlation between ENSO and temperature which is particularly strong in the tropics; this is consistent with the ERBE data from Lindzen.
6 If the ERBE data is correct [with a surprise possibly due from Miskolczi] then AGW cannot rely on the radiative imbalance to power OHC increase similtaneous with atmospheric increase.
7 McLean’s conclusion about ENSO oscillation and consequent temperature trends falling and rising [as they specifically say in their abstract] would therefore be true because no mechanism for any non-oscillating trend consistent with non-natural [ie AGW] exists.
8 Tamino’s critique of the statistical exclusion by McLean of trends other than ENSO is therefore irrelevant. Incidentally and as a matter of curiosity Tamino agrees that ENSO causes oscillations in temperature; the odd thing is that his calculation and graphical depiction of the underlying temperature trend with ENSO removed;
is the same as the temperature trend with ENSO intact;
http://woodfortrees.org/plot/gistemp/from:1976/to:2010/trend/plot/gistemp/from:1976/to:2010
Ok Nick I think I've got a handle on your [and AGW's] position; the SST increases through a decrease in upwelling; this correlates [causes/is caused by] with PDO phase shift in 1976 and probably 1998 as David's break paper shows; the SST increase can warm the atmosphere but this transfer of heat to the atmosphere must logically cool the ocean [since the ocean can't heat itself] which hasn't happened; your position is that the IR transfer from the ocean surface is absorbed and back-radiated to the oceans; you rely on the radiative imbalance at TOA to back this up; you prefer this to Bob's conjecture that cloud cover diminution has enabled greater insolation to maintain the SST; a couple of points;1 Lindzen's new paper with Choi shows that “outgoing radiation fluxes increase with the increase in SSTs”; as well “the feedback in ERBE is mostly from shortwave radiation while the feedback in the models is mostly from longwave radiation”.2 ISCCP data shows low and global cloud cover declining since 1987; ICOADs shows the decline from 1998; so a mixed bag there with ISCCP supporting Bob's point as Indigo points out.3 The window or S_T in Miskolczi parlance would play a part here if M's figure of 62 was true rather than K&T's 40; on this I'll simply say that some developments are in the offing about that.4 If increased SW is coming in concurrent with the increased SST the positive feedback would be there to satisfy both the atmospheric temperature increase and OHC increase.5 If the above is reasonable than what McLean et al have done is isolate a lag correlation between ENSO and temperature which is particularly strong in the tropics; this is consistent with the ERBE data from Lindzen.6 If the ERBE data is correct [with a surprise possibly due from Miskolczi] then AGW cannot rely on the radiative imbalance to power OHC increase similtaneous with atmospheric increase.7 McLean's conclusion about ENSO oscillation and consequent temperature trends falling and rising [as they specifically say in their abstract] would therefore be true because no mechanism for any non-oscillating trend consistent with non-natural [ie AGW] exists.8 Tamino's critique of the statistical exclusion by McLean of trends other than ENSO is therefore irrelevant. Incidentally and as a matter of curiosity Tamino agrees that ENSO causes oscillations in temperature; the odd thing is that his calculation and graphical depiction of the underlying temperature trend with ENSO removed;http://tamino.files.wordpress.com/2008/11/g-m-v…is the same as the temperature trend with ENSO intact;http://woodfortrees.org/plot/gistemp/from:1976/…
“Coho, you, or someone, needs to present a believable heat flow pattern for “ENSO heating”.”If circulation changes deposit heat in places where the infrared opacity is greater or less, there would be changes in temperature from that deposition.
Comparing the three OHC datasets illustrated in Levitus et al (2009), the sudden rise in 2003 in the Levitus OHC makes them the outlier.http://i43.tinypic.com/1zp5j42.pngTo me Domingues appears to represent reality, regardless of whether or not you include the 1958 spike. Look at the data after 1960. It declines until 1976/77, then increase from there.
That's consistent with the ocean responding to surface temperature. It's the opposite of what you'd expect if the ocean is passing heat to the surface.
David S says “A potential AGW buster” – OMIGAWD !
Mate is that your serious take on the paper or its press release.
If you want to defend your position as a serious sceptic just walk away quickly and we’ll never speak of it again. Surely you wouldn’t touch McLean’s stuff with a barge pole. What what Bob thinking !
Parker et al have done the better analysis showing a long scale centennial trend overlain by episodic phenomena such as ENSO/PDO and AMO as lesser effects.
Meehl 2009 has given us some terrific insight as to the IPO interacting with the greenhouse forcing.
And if you thought about Smith and Power you’d be most worried about the stability of the SOI as an index with the Walker circulation starting to trend. (signs of AGW – wooo oooo – ghostly music)
And the new reality is that if you can’t replicate your hypothesis in a model you’re not even in the game space. You won’t get the interactions.
David S says “A potential AGW buster” – OMIGAWD !Mate is that your serious take on the paper or its press release.If you want to defend your position as a serious sceptic just walk away quickly and we'll never speak of it again. Surely you wouldn't touch McLean's stuff with a barge pole. What what Bob thinking !Parker et al have done the better analysis showing a long scale centennial trend overlain by episodic phenomena such as ENSO/PDO and AMO as lesser effects.Meehl 2009 has given us some terrific insight as to the IPO interacting with the greenhouse forcing.And if you thought about Smith and Power you'd be most worried about the stability of the SOI as an index with the Walker circulation starting to trend. (signs of AGW – wooo oooo – ghostly music)And the new reality is that if you can't replicate your hypothesis in a model you're not even in the game space. You won't get the interactions.
Wow, I can’t believe you are jumping on this paper. First they remove all trends from their dataset, then claim to prove that the trends can be explained by ENSO. This goes beyond scientific ignorance, it’s borderline manipulative.
Wow, I can't believe you are jumping on this paper. First they remove all trends from their dataset, then claim to prove that the trends can be explained by ENSO. This goes beyond scientific ignorance, it's borderline manipulative.
slincon and luke: If you read beyond the first sentence you’ll see that I reported the flaw, before I read it on RC and Tamino. Flawed claims are flawed, whether they are made by Rahmstorf or McLean.
slincon and luke: If you read beyond the first sentence you'll see that I reported the flaw, before I read it on RC and Tamino. Flawed claims are flawed, whether they are made by Rahmstorf or McLean.
I have read the paper. McLean made a defence comment at Tamino's site and received a cursory accusation of being a liar, amongst other things. Grant Foster (Tamino) says that he will be submitting a comment to JGR. I think it is up to the authors to defend their paper. However, they will never convince committed warmists such as Tamino and the Team (RC). I think their mathematics could have been better audited (although Craig Lohele did advise them).
Thanks for the alert richard. I agree with Tamino that the statements about general trends shouldn't be in the paper, but I disagree that its the smoothing that increases the correlation, or that the correlation is spurious. I'm not saying more until I write up my comment. As for dishonesty about unsupported claims, I don't see these guys paying out on Rahmstorf, so who's the hypocrite.
“I don't see these guys paying out on Rahmstorf, so who's the hypocrite.”That is because Rahmstorf is one of the “team”. I have never seen Tamino or RC pay out on one of their own and I guess I never will.
In relation to your first paragraph. I think if you investyigate further you will find Bob Carter is an expat Kiwi. That would make the paper a true trans-Tasman effort being 1 1/2 researchers each
And John McLean is a member of the NZ climate coalition. I think we could say this is an all-NZ effort 🙂
In relation to your first paragraph. I think if you investyigate further you will find Bob Carter is an expat Kiwi. That would make the paper a true trans-Tasman effort being 1 1/2 researchers each
luke is demonstrating LTP in anthromorphic form; the break in data will not be represented by Parker’s PCA, but keep echoing the mantra.
Good to see you are also de ju viewing the Power and Smith effort;
http://www.agu.org/pubs/crossref/2007/2007GL030854.shtml
Which is contradicted by the Cayon, Dettinger and Auad paper;
Click to access Global_Warm_ENSO.pdf
not to mention Tsonis’s recent paper which was the subject of a thread here previously.
You do appreciate luke, that if David can establish a concurrent break around 1976, with a lag consistent with that found by McLean et al, that will not only give some support to their SOI thesis, despite the statistical ambiguity, but will provide another mechanism for David’s “break” paper. 2 breaks beats 3 EOFs any day of the week.
luke is demonstrating LTP in anthromorphic form; the break in data will not be represented by Parker's PCA, but keep echoing the mantra.Good to see you are also de ju viewing the Power and Smith effort;http://www.agu.org/pubs/crossref/2007/2007GL030…Which is contradicted by the Cayon, Dettinger and Auad paper;http://meteora.ucsd.edu/papers/auad/Global_Warm…not to mention Tsonis's recent paper which was the subject of a thread here previously.You do appreciate luke, that if David can establish a concurrent break around 1976, with a lag consistent with that found by McLean et al, that will not only give some support to their SOI thesis, despite the statistical ambiguity, but will provide another mechanism for David's “break” paper. 2 breaks beats 3 EOFs any day of the week.
I'm trying to understand (qualitatively) your comment.My crude understanding of what you said is :1) that El Nino moves warm water to the surface of the E. Pacific. Cloud cover over the E. Pacific increases in response to this warm surface water, retaining this heat more than would be without cloud cover. 2) Meanwhile, cold water has surfaced in W. Pacific, resulting in less cloud cover, and that this increased shortwave radiation reaching the ocean surface by 25W/sq meter.3) You didn't state it explicitly, but apparently the combination 1 and 2 mean more total energy absorbed over the entire tropical Pacific zone than during non-El Nino times.I know that this may be a further simplification of an already simplified explanation, but as a novice in the climate field I'm still trying to get oriented.———————-It seems that part of your description is an assumption (observation?) that cloud cover increases in E. Pacific during an El Nino event. That seems to be opposite of the recent paper discussed at http://wattsupwiththat.com/2009/07/25/july-24th…Your comment over in that thread included “During El Nino events, the cloud cover and precipitation follow the warm water from the Pacific Warm Pool to the Central and Eastern Equatorial Pacific.”Is there something unusual in this situation that causes cloud cover and precipitation to follow the warm water, or would you expect that in general warm water would have higher cloud cover?
And John McLean is a member of the NZ climate coalition. I think we could say this is an all-NZ effort 🙂
Is there a cloud explanation for the PDO, AMO and decadal ENSO modulation? It makes physical sense with a decrease in cloud to 2000 and an increase since.
‘Global warming due to increasing absorbed solar radiation
Kevin E. Trenberth
National Center for Atmospheric Research, Boulder, Colorado, USA
John T. Fasullo
National Center for Atmospheric Research, Boulder, Colorado, USA
Global climate models used in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) are examined for the top‐of‐atmosphere radiation changes as carbon dioxide and other greenhouse gases build up from 1950 to 2100. There is an increase in net radiation absorbed, but not in ways commonly assumed. While there is a large increase in the greenhouse effect from increasing greenhouse gases and water vapor (as a feedback), this is offset to a large degree by a decreasing greenhouse effect from reducing cloud cover and increasing radiative emissions from higher temperatures. Instead the main warming from an energy budget standpoint comes from increases in absorbed solar radiation that stem directly from the decreasing cloud amounts. These findings underscore the need to ascertain the credibility of the model changes, especially insofar as changes in clouds are concerned.’
This one floored me. Are they saying that increasing water vapor causes reducing cloud cover or are they saying the cloud cover reduction causing the heating (the much-derided Swindle argument)? The former doesn’t make too much sense and the latter doesn’t sound like Trenberth at all. Or are they merely saying the models are crap?
Is there a cloud explanation for the PDO, AMO and decadal ENSO modulation? It makes physical sense with a decrease in cloud to 2000 and an increase since. 'Global warming due to increasing absorbed solar radiationKevin E. TrenberthNational Center for Atmospheric Research, Boulder, Colorado, USAJohn T. FasulloNational Center for Atmospheric Research, Boulder, Colorado, USAGlobal climate models used in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) are examined for the topâ€ofâ€atmosphere radiation changes as carbon dioxide and other greenhouse gases build up from 1950 to 2100. There is an increase in net radiation absorbed, but not in ways commonly assumed. While there is a large increase in the greenhouse effect from increasing greenhouse gases and water vapor (as a feedback), this is offset to a large degree by a decreasing greenhouse effect from reducing cloud cover and increasing radiative emissions from higher temperatures. Instead the main warming from an energy budget standpoint comes from increases in absorbed solar radiation that stem directly from the decreasing cloud amounts. These findings underscore the need to ascertain the credibility of the model changes, especially insofar as changes in clouds are concerned.'
Nick, I'm not too sure what you meant by “It's the opposite of what you'd expect if the ocean is passing heat to the surface.” The sea surface is included in the calculation of OHC.
Why doesn't it make sense?
Sorry, I misread your comment.
What I mean is that surface temps went down, until 1976, then rose. OHC did the same. That's consistent with a downward flux responding to surface temp. If it was the ocean exchanging heat with the atmosphere that caused the air cooling and then heating, then the ocean should have gained heat to 1976, then cooled as the heat passed (via ENSO) to the air.Now I know you said that clouds might have a counter effect. All I'm saying is that they would have to turn the heat flow around completely. And I don't think there's evidence of that much cloud effect.
Apologies, I need more time to study this. Please disregard if irrelevant. I’ll start with an analogy, which is not always good. In this case it’s a cooktop on a stove.
If you use a thermometer and find the cooktop is hot, you can conclude that it was cooler and is heating, or that it was hotter and is cooling, or that it is always that way. You need another dimension to get the answer. That dimension might be energy input (is the electric switch on?) or it might be time (If we wait 10 mins we can pick the trend) or it might be space (is the region closer to the heating element hotter or colder than the surface of the heated coil?)
Now we go to the very surface of the oceans, where they meet air. There is supposed to be unprecedented warming at this interface in the last month or so, (July 2009), with the inference that the GHG effect is heating the ocean surface. But, the oceans must be losing heat at this interface, because of thermodynamics taking energy from hot to cold.
There are several possible paths to gain or lose temperature at this interface, like conduction, convection, radiation, latent heat of evaporation. It is possible that several of these are happening at the same time.
One unpublished official view is that the oceans are heating because the heat flow is from the top down. But is this not the usual case? The sunlight hitting the top heats the surface and some pathways take it deeper. Only hot upwelling would cause a reverse direction within the sea phase.
How does a hot ocean surface skin interact with the atmosphere? I don’t know the relative amounts of the possible mechanisms like evaporation, cooling by rainfall, radiation (at which wavelengths, if relevant), conduction etc.
In short, is it possible to be dogmatic that a hot ocean surface over a cooler undersurface is an irrefutable indication of global warming? It it not possible that it simply represents the distribution of both hot and cold currents at the surface, which changes with time, to give a variable average? I guess this is another way to describe things with acronyms like PDO, SOI, El Nino, etc.
There is no compelling reason I have seen why the mechanims that might change SST globally have to be associated with each other in time or even have a common causative effect (apart from the Sun being the dominant heat sorce).
Is this too simplistic?
I don’t think people are inferring that recent Pacific warming is especially due to GHG. Most think it is just a movement of waters which has brought warm to the surface.
The oceans are always exchanging heat with the air. Think maritime climates etc. Surface conduction, augmented by wind, and evaporation are important. So is IR, with absorption by GHG.
Globally, Trenberth gives 80 W/m2 for latent heat and 396 W/m2 for IR. These are big numbers, and temperature sensitive, and they are dominated by the ocean part, so the numbers there will be similar. There is plenty of capacity for the warmer ocean to heat the air.
So, no, ENSO doesn’t prove AGW – and I don’t think anyone is saying that.
Don’t your questions apply to Swanson and Tsonis’s analysis too. And don’t they also apply to attempts at explaining away the recent non-warming by reference to natural cycles. But if a decade of surplus heat can hide in a non-warming sea then surely anything’s possible.
Which questions? I didn’t ask any. And I don’t believe I said anything that any reasonable sceptic would dispute.
Well now you have (wait, am I “reasonable”? Hm…)-It’s not that I’m disagreeing with any prior things you’ve said (I’m trying to see where to start with your comments to see if there is anything that I might take issue with, but nothing so far) but “reasonable” is a slippery word…how would you define such a thing?
Andrew, I’m not saying that I never say things that you could disagree with. But James took issue with a particular response to sherro, and I just can’t see what the issue is.
Nick-my question of what “reasonable skeptic” is still stands. What makes one reasonable or unreasonable?
See what I mean? 🙂
Ok statements then; re problems with the natural variation defense and the lack of a natural mechanism to explain it all.
You say that someone had to come up with a mechanism. Well Swanson/Tsonis flat out stated that they don’t know the natural mechanism for their theory but apparently their analysis is now fashionable at realclimate.org seemingly because it can explain 10 years of non-cooling without the increasingly embarrassing aerosol handwave and yet still handily containing a long term trend that can be blamed on GHG’s. And exactly why can that long term trend be blamed on GHG’s? Because of the lack of an alternative natural mechanism. Do you see the contradiction?
So yes it’s eminently reasonable to be skeptical and seek rationality in the guesswork but it would be nice to see it evenly applied.
Another example, referring to your own words:
“Atmos radiative transfer produces a flux imbalance, which takes the form of 1.6 W/m2 excess downwelling IR. This warms the surface, which produces a partly countervailing upward IR. But most of the heat continues downward into the ocean, which warms as observed.”
Except that the only reliable ocean heat measurement shows cooling from 2003 with a still rising postulated excess heat from GHG’s. Has someone come up with a mechanism for that?
James, my point is simply that if you are proposing that ENSO, which intermittently exchanges heat between the ocean and atmosphere, is a source of longterm heating of the air and surface, then you would look for evidence of where the heat is coming from. Ocean heat content measurements are noisy, but do show a long term accumulation of heat, which rules them out as a long term source.
RC has given space to Swanson for an exposition of their theory, but I don’t think it’s been passionately embraced.
I would recommend caution about recent cooling (or non-heating) of oceans. There’s a review article here. There’s always been noise in the data – ARGO is promising, but the instrumentation issues need time. Sea levels are still rising.
“Sea levels are still rising.”
And interestingly, the rate of change is slowing:
http://www.worldclimatereport.com/index.php/2009/07/22/sea-level-rise-an-update-shows-a-slowdown/
Apologies, I need more time to study this. Please disregard if irrelevant. I'll start with an analogy, which is not always good. In this case it's a cooktop on a stove.If you use a thermometer and find the cooktop is hot, you can conclude that it was cooler and is heating, or that it was hotter and is cooling, or that it is always that way. You need another dimension to get the answer. That dimension might be energy input (is the electric switch on?) or it might be time (If we wait 10 mins we can pick the trend) or it might be space (is the region closer to the heating element hotter or colder than the surface of the heated coil?)Now we go to the very surface of the oceans, where they meet air. There is supposed to be unprecedented warming at this interface in the last month or so, (July 2009), with the inference that the GHG effect is heating the ocean surface. But, the oceans must be losing heat at this interface, because of thermodynamics taking energy from hot to cold. There are several possible paths to gain or lose temperature at this interface, like conduction, convection, radiation, latent heat of evaporation. It is possible that several of these are happening at the same time.One unpublished official view is that the oceans are heating because the heat flow is from the top down. But is this not the usual case? The sunlight hitting the top heats the surface and some pathways take it deeper. Only hot upwelling would cause a reverse direction within the sea phase. How does a hot ocean surface skin interact with the atmosphere? I don't know the relative amounts of the possible mechanisms like evaporation, cooling by rainfall, radiation (at which wavelengths, if relevant), conduction etc. In short, is it possible to be dogmatic that a hot ocean surface over a cooler undersurface is an irrefutable indication of global warming? It it not possible that it simply represents the distribution of both hot and cold currents at the surface, which changes with time, to give a variable average? I guess this is another way to describe things with acronyms like PDO, SOI, El Nino, etc.There is no compelling reason I have seen why the mechanims that might change SST globally have to be associated with each other in time or even have a common causative effect (apart from the Sun being the dominant heat sorce).Is this too simplistic?
I don't think people are inferring that recent Pacific warming is especially due to GHG. Most think it is just a movement of waters which has brought warm to the surface.The oceans are always exchanging heat with the air. Think maritime climates etc. Surface conduction, augmented by wind, and evaporation are important. So is IR, with absorption by GHG.Globally, Trenberth gives 80 W/m2 for latent heat and 396 W/m2 for IR. These are big numbers, and temperature sensitive, and they are dominated by the ocean part, so the numbers there will be similar. There is plenty of capacity for the warmer ocean to heat the air. So, no, ENSO doesn't prove AGW – and I don't think anyone is saying that.
This one floored me. Are they saying that increasing water vapor causes reducing cloud cover or are they saying the cloud cover reduction causing the heating (the much-derided Swindle argument)? The former doesn't make too much sense and the latter doesn't sound like Trenberth at all. Or are they merely saying the models are crap?
Don't your questions apply to Swanson and Tsonis's analysis too. And don't they also apply to attempts at explaining away the recent non-warming by reference to natural cycles. But if a decade of surplus heat can hide in a non-warming sea then surely anything's possible.
Which questions? I didn't ask any. And I don't believe I said anything that any reasonable sceptic would dispute.
Well now you have (wait, am I “reasonable”? Hm…)-It's not that I'm disagreeing with any prior things you've said (I'm trying to see where to start with your comments to see if there is anything that I might take issue with, but nothing so far) but “reasonable” is a slippery word…how would you define such a thing?
Ok statements then; re problems with the natural variation defense and the lack of a natural mechanism to explain it all. You say that someone had to come up with a mechanism. Well Swanson/Tsonis flat out stated that they don't know the natural mechanism for their theory but apparently their analysis is now fashionable at realclimate.org seemingly because it can explain 10 years of non-cooling without the increasingly embarrassing aerosol handwave and yet still handily containing a long term trend that can be blamed on GHG's. And exactly why can that long term trend be blamed on GHG's? Because of the lack of an alternative natural mechanism. Do you see the contradiction? So yes it's eminently reasonable to be skeptical and seek rationality in the guesswork but it would be nice to see it evenly applied.Another example, referring to your own words:”Atmos radiative transfer produces a flux imbalance, which takes the form of 1.6 W/m2 excess downwelling IR. This warms the surface, which produces a partly countervailing upward IR. But most of the heat continues downward into the ocean, which warms as observed.”Except that the only reliable ocean heat measurement shows cooling from 2003 with a still rising postulated excess heat from GHG's. Has someone come up with a mechanism for that?
@JamesG
James,
the 1.6 W/m2 excess downwelling radiation or radiative forcing from the IPCC is referenced back to 1750 A.D. So it is the difference between radiative forcing now and radiative forcing in 1750 A.D.
The IPCC defines radiative forcing for greenhouse gases always with respect to 1750.
The radiative forcing that needs to be compared to the current heating rate of a certain observation period really is the difference between the radiative forcing at the end of the observation period and radiative forcing at the beginning of the observation period. I do not know these numbers. However, 1.6 W/m2 cannot be compared to the heating rate directly.
Willis at al (J. Geophys. Res. 113, C06015 (2008)) report for the period since 2003 a ocean heat storage rate of -0.076 +/- 0.214 W/m2. This is 90% of the actual heating that has occurred since 2003.
Best regards
Günter
@JamesGJames,the 1.6 W/m2 excess downwelling radiation or radiative forcing from the IPCC is referenced back to 1750 A.D. So it is the difference between radiative forcing now and radiative forcing in 1750 A.D.The IPCC defines radiative forcing for greenhouse gases always with respect to 1750.The radiative forcing that needs to be compared to the current heating rate of a certain observation period really is the difference between the radiative forcing at the end of the observation period and radiative forcing at the beginning of the observation period. I do not know these numbers. However, 1.6 W/m2 cannot be compared to the heating rate directly.Willis at al (J. Geophys. Res. 113, C06015 (2008)) report for the period since 2003 a ocean heat storage rate of -0.076 +/- 0.214 W/m2. This is 90% of the actual heating that has occurred since 2003.Best regardsGünter
Andrew, I'm not saying that I never say things that you could disagree with. But James took issue with a particular response to sherro, and I just can't see what the issue is.
James, my point is simply that if you are proposing that ENSO, which intermittently exchanges heat between the ocean and atmosphere, is a source of longterm heating of the air and surface, then you would look for evidence of where the heat is coming from. Ocean heat content measurements are noisy, but do show a long term accumulation of heat, which rules them out as a long term source.RC has given space to Swanson for an exposition of their theory, but I don't think it's been passionately embraced.I would recommend caution about recent cooling (or non-heating) of oceans. There's a review article here. There's always been noise in the data – ARGO is promising, but the instrumentation issues need time. Sea levels are still rising.
Nick-my question of what “reasonable skeptic” is still stands. What makes one reasonable or unreasonable?See what I mean? 🙂
“Sea levels are still rising.”And interestingly, the rate of change is slowing:http://www.worldclimatereport.com/index.php/200…
Please permit 2 comments to clarify what I seem to have made unclear.
1. From whence comes the sudden power to warm the ocean surface in a month? And why does it seem to effect a lot of the globe simultaneiously?
2. Here is an official explanation in partial answer to the above. I have not cleared this with the author so no names:
“There are “two” processes at work. The enhanced greenhouse effect which has established a near monotonic warming trend of 0.15C/decade (give or take). Then there is everything else (mostly natural) which is noise on top of the montonic trend. Sometimes the noise adds to global warming and sometimes it takes away. In 1998 and 2005 the El Nino added (about) 0.2 and 0.1C to global warming. In recent years the La Nina took away (about) 0.1C. We are now in transition from La Nina to El Nino and have a very cool sun (perhaps the strongest solar minimum for a century). I suspect that the combination of all natural forcing is for a near zero effect ATM and we are now about equal with 1998 (perhaps a slight cooling). As the El Nino develops we will add to global warming and see monthly 1998 records and quite possibly the annual 1998 record bettered (though noting 1998 was perfectly timed wrt to the calendar year as it took most of the year for the El Nino to dissipate).
The coming year is going to be extremely difficult for sceptics as global warming takes off. The true sceptics will give up the game, or at least moderate their opinions which are rapidly loosing what little support they had.”
Now Nick and James and Andrew, I’m departing this argument and leaving others to argue out the meaning of the quote.
Please permit 2 comments to clarify what I seem to have made unclear.1. From whence comes the sudden power to warm the ocean surface in a month? And why does it seem to effect a lot of the globe simultaneiously?2. Here is an official explanation in partial answer to the above. I have not cleared this with the author so no names:”There are “two” processes at work. The enhanced greenhouse effect which has established a near monotonic warming trend of 0.15C/decade (give or take). Then there is everything else (mostly natural) which is noise on top of the montonic trend. Sometimes the noise adds to global warming and sometimes it takes away. In 1998 and 2005 the El Nino added (about) 0.2 and 0.1C to global warming. In recent years the La Nina took away (about) 0.1C. We are now in transition from La Nina to El Nino and have a very cool sun (perhaps the strongest solar minimum for a century). I suspect that the combination of all natural forcing is for a near zero effect ATM and we are now about equal with 1998 (perhaps a slight cooling). As the El Nino develops we will add to global warming and see monthly 1998 records and quite possibly the annual 1998 record bettered (though noting 1998 was perfectly timed wrt to the calendar year as it took most of the year for the El Nino to dissipate). The coming year is going to be extremely difficult for sceptics as global warming takes off. The true sceptics will give up the game, or at least moderate their opinions which are rapidly loosing what little support they had.”Now Nick and James and Andrew, I'm departing this argument and leaving others to argue out the meaning of the quote.
Nick; that Dominiques paper at RC has an alternative treatment here;
http://climatesci.org/2008/06/20/diagnosis-of-global-sea-level-and-upper-ocean-heat-content-on-seasonal-to-interannual-timescales-paper-willis-et-al-2008-published/
And Sherro quotes someone saying it’s going to get even harder for sceptics due to [AG]Warming taking off again; well it will be a mixed bag for me; at least I will be warmer; I’m sick of the cold.
Well, Coho, my view on OHC remains – wait and see when the new instrumentation is settled. It’s reinforced by a Willis statement at that link “suggesting that systematic long-period errors remain in one or more of these observing systems” (which doesn’t quite gel with the mention of unprecedented accuracy).
And don’t worry about El Nino. We’d never confuse weather with climate 🙂 But I must say I’m sick of the drought.
Nick; that Dominiques paper at RC has an alternative treatment here;http://climatesci.org/2008/06/20/diagnosis-of-g…And Sherro quotes someone saying it's going to get even harder for sceptics due to [AG]Warming taking off again; well it will be a mixed bag for me; at least I will be warmer; I'm sick of the cold.
Well, Coho, my view on OHC remains – wait and see when the new instrumentation is settled. It's reinforced by a Willis statement at that link “suggesting that systematic long-period errors remain in one or more of these observing systems” (which doesn't quite gel with the mention of unprecedented accuracy).And don't worry about El Nino. We'd never confuse weather with climate 🙂 But I must say I'm sick of the drought.
Well, Coho, my view on OHC remains – wait and see when the new instrumentation is settled. It's reinforced by a Willis statement at that link “suggesting that systematic long-period errors remain in one or more of these observing systems” (which doesn't quite gel with the mention of unprecedented accuracy).And don't worry about El Nino. We'd never confuse weather with climate 🙂 But I must say I'm sick of the drought.
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