The author of the recent SkepticalScience post Distinguishing Between Short-Term Variability and Long-Term Trends, Dana Nuccitelli, still misunderstands or misrepresents El Niño and La Niña processes. Either way, he’s missed something. The instrument temperature record indicates that La Niñas and El Niños serve as a natural recharge-discharge oscillator, with La Niñas acting as the recharge mode and El Niños serving as the discharge and distribution phase. As such, the data indicate that El Niño and La Niña events are responsible for the natural warming of global sea surface temperatures over the past 31 years and that they’re the cause of a portion of the warming of ocean heat content since 1955. If this subject is new to you, refer to my illustrated essay “The Manmade Global Warming Challenge” [42MB]. Also, we’ve discussed time and again that an El Niño-Southern Oscillation (ENSO) index only represents the impacts of ENSO on the variable being measured, and that an ENSO index does not represent all of the ENSO processes or their aftereffects, but the SkepticalScience author Dana Nuccitelli continues to present myths about ENSO indices—and, in turn, about global warming.
I have not read the recent post by Dana Nuccitelli in its entirety. Based on the opening paragraph, it looks to be a comment on the McLean et al (2009) paper Influence of the Southern Oscillation on tropospheric temperature. This post is not a defense of that paper. It’s about the closing statement of Dana Nuccitelli’s post, which is clearly a falsehood. Nuccitelli writes:
If we remove the long-term warming trends, we can see once again that the short-term wiggles in the temperature data are strongly influenced by changes in ENSO. However, the long-term global warming trends are not – they are due to the human-caused greenhouse effect.
Here’s a challenge to Dana Nuccitelli and other bloggers from SkepticalScience. You and your associates at SkepticalScience claim to have analyzed more than 12,000 peer-reviewed papers about global warming and climate change. What I present in the following should be a really easy task, because lower troposphere temperature anomalies for the mid-to-high latitudes of the Northern Hemisphere warmed in a very specific way. Surely, out of the 12,000 papers, a few of them must have addressed how lower troposphere temperatures have actually warmed.
If you believe that manmade greenhouse gases are responsible for the recent bout of global warming, please provide links to the climate model-based, peer-reviewed papers that explain:
1. How and why the lower troposphere temperature anomalies of the mid-latitudes of the Northern Hemisphere show upward shifts in response to strong El Niño events—without proportional cooling during the trailing La Niñas. That is, the RSS lower troposphere temperature anomalies for the latitudes of 20N-90N do not cool proportionally during the La Niña event of 1988/89, Figure 1, but they did warm in response to the 1986/87/88 El Niño, which caused a major portion of the long-term warming trend.
Figure 1
2. And how and why the RSS lower troposphere temperature anomalies for the latitudes of 20N-90N do not cool proportionally during the La Niña event of 1998-01, Figure 2, but they did warm significantly in response to the 1997/98 El Niño, which caused another major portion of the long-term trend.
Figure 2
It is blatantly obvious to anyone reading and comprehending those two graphs that there would be little to no long-term warming of the lower troposphere temperature anomalies for mid-to-high latitudes of the Northern Hemisphere if lower troposphere temperature anomalies had cooled proportionally during the La Niña events of 1988/89 and 1998-01.
I first discussed the warming of lower troposphere temperature data almost 4 years ago in the post RSS Time Latitude Plots Show Climate Responses That Cannot Be Easily Illustrated With Time-Series Graphs Alone. And I discussed why the lower troposphere temperature anomalies for the mid-to-high latitudes of the Northern Hemisphere do not cool proportionally during the 1988/89 and 1998-01 La Niñas in the post The ENSO-Related Variations In Kuroshio-Oyashio Extension (KOE) SST Anomalies And Their Impact On Northern Hemisphere Temperatures.
Back to Nuccitelli’s closing statement: That was the same conclusion reached in a recent video by SkepticalScience, using surface temperatures. I responded to their video with the post The Blatant Errors in the SkepticalScience Video “Global Warming over the Last 16 Years”, which includes the following YouTube video:
DON’T FORGET SEA SURFACE TEMPERATURE AND OCEAN HEAT CONTENT
Further to my challenge to Dana Nuccitelli and his associates at SkepticalScience: if you continue to believe that manmade greenhouse gases are responsible for the recent bout of global warming, please provide links to the climate model-based, peer-reviewed papers that explain how and why sea surface temperature and ocean heat content data have warmed (or not warmed) in the following ways (numbering continued from preceding section):
3. How and why the sea surface temperatures of the East Pacific (90S-90N, 180-80W) haven’t warmed in 31 years (Figure 3).
Figure 3
4. How and why the sea surface temperatures of the Atlantic, Indian and West Pacific Oceans (Figure 4) with the coordinate of 90S-90N, 80W-180, only warmed during the strong El Niño events of 1986/87/88, 1997/98 and 2009/10 and did not cool proportionally during the training La Niñas—and without those El Niño events, the sea surface temperatures there would show no warming.
Figure 4
That should be a simple task since the global oceans were only broken down into two subsets.
Moving now to ocean heat content of the tropical Pacific where the fuel for El Niño events is generated:
5. How and why the warming of the ocean heat content data for the tropical Pacific, Figure 5, is dependent on the 1973-76 and 1995/96 La Niña events, and without those La Niñas the ocean heat content for tropical Pacific would cool.
Figure 5
Still in the subject of ocean heat content:
6. How and why the warming of the ocean heat content of the North Pacific (north of the tropics) is dependent on a 2-year climate shift (1989-90), and without that climate shift, the ocean heat content for the North Pacific would cool (Figure 6).
Figure 6
I discussed the above four graphs and the natural processes that caused their warming in the illustrated essay “The Manmade Global Warming Challenge” [42MB] and in the YouTube video series “The Natural Warming of the Global Oceans” Part 1 and Part 2. And I also discussed them in great detail in my ebook Who Turned on the Heat? which is available in pdf form for only US$8.00. Who Turned on the Heat? also discusses the warming of lower troposphere temperature anomalies shown in Figures 1 and 2.
CLOSING
There’s no reason to wait for links to peer-reviewed papers from Dana Nuccitelli and his associates at SkepticalScience—links that will offer climate model-based explanations for how and why the oceans have warmed in the fashions they’ve warmed and how the lower troposphere temperature anomalies warmed as they had. The warming is dependent on ENSO, and for the ocean heat content of the North Pacific, it depends on a change in wind patterns and sea level pressure. The first problem they’ll encounter is trying to find studies based on climate models that can simulate ENSO. As far as I know, there are a sum total of…How should I put this?…none. See Guilyardi et al (2009), discussed in the post here.
I used the phrases “if you believe” and “if you continue to believe” as part of the challenges to SkepticalScience. Sea surface temperatures, ocean heat content and lower troposphere temperatures have all warmed in very specific ways in response to ENSO. Unless there are climate model-based peer-reviewed papers that explain specifically how and why those variables have actually warmed in the manners in which they’ve warmed as responses to ENSO, then parties like SkepticalScience who are promoting hypothetical manmade global warming are doing so based solely on their beliefs.
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I wrote “I am wrong about this?”
Having done some more research, it seems I may have been mislead by a graph. The latent heat flux likely is larger during La Nina episodes. Please, disregard this specific objection.
Bob says: “Until they can, there is no way to even suggest that manmade greenhouse gases have had any impact on the warming of sea surface temperatures and ocean heat content.
Brian, you’re overlooking the obvious. According to IPCC, only anthropogenic forcings can explain the warming over the past 30 years:”
I’m not sure why you boil this down to such a black and white issue. I do not believe that ocean warming can only be due to anthropogenic forcings. I believe that almost any forcing can be suggested at this point, but none have been proved. I am not arguing in favor of Foster and Rahmstorf, Thompson, SkS, the IPCC, or any CAGW agenda. You are wasting your own time by lumping me in with them. In your extremely lengthy response, you have directly answered one of my four major concerns, about peer-reviewed evidence. I don’t agree with your answer, but you certainly cleared up your stance on the issue. Thanks for that. I will no longer bring up that point.
Here are the other thee that remain unaddressed:
1. No one is disputing your data or observations. Myself and others have disputed the conclusions that you draw from the data (that ENSO can explain away AGW in the oceans).
2. Reduced cloud cover is one of the causes of each step change. You have yet to explain why there have been more steps up in temperature, creating a decades-long net warm trend.
3. Removing El Nino from a temperature plot is misleading, as it removes a possible mechanism for AGW to manifest itself.
You can talk about warm water that models don’t account for all day long. I’m not discussing AGW models here, only you are. There is a huge difference between saying models are not accounting for natural ENSO warming, and saying that there is no way to suggest any GHG forcing in the oceans.
The Ray and Giese paper is a good start. I’m unsure how to interpret the last sentence of their abstract, since earlier they say “As has been previously shown for the strength and location of ENSO there is little overall trend in the characteristics.” So if they are saying there is no ENSO trend regardless, that seems to go against your hypothesis. They could be implying that warming is seen in the oceans without affecting ENSO over the long term. I don’t have access to the paper though, so I don’t know what they are really trying to say. Are there any others you know of that deal with this?
It is blatantly obvious to anyone reading and comprehending those two graphs that there would be little to no long-term warming of the lower troposphere temperature anomalies for mid-to-high latitudes of the Northern Hemisphere if lower troposphere temperature anomalies had cooled proportionally during the La Niña events of 1988/89 and 1998-01.
What’s your point? Accumulated CO2 prevents the La Niña event from cooling after facilitating El Niño warming? I wouldn’t say that it does, but I do not think that your data rule it out.
Matthew R Marler says: “What’s your point? Accumulated CO2 prevents the La Niña event from cooling after facilitating El Niño warming?”
I’m not sure how you could jump to that conclusion. Just the opposite. The paragraph you quoted was followed by one that discussed two prior posts about TLT data. The second link included a detailed discussion that basically boils down to the leftover warm water from the 1986/87/88 and 1997/98 El Niño events counteract the effects of the trailing La Niñas and keeps the lower troposphere temperature anomalies of the mid-to-high latitudes Northern Hemisphere from cooling during those La Niñas.
Brian, are you aware that there is no long-term warming trend in the sea surface temperature anomalies of the eastern equatorial Pacific?
http://oi46.tinypic.com/11s36ua.jpg
Are you aware that, even though there is no long-term trend, there is a decadal/multidecadal component to ENSO?
http://i43.tinypic.com/33agh3c.jpg
If CO2 was driving the El Nino dominated period, why have NINO3.4 sea surface temperature anomalies turned back to La Nina conditions?
Bob, when you speak of the “leftover warm water” for an El Niño even, do you mean to refer (1) to an active area where the SST anomaly remains high (down to the thermocline) on account of some active ocean/atmosphere dynamical heat transfer process, or continuous forcing, or (2) do you rather mean to refer to the simple release of the accumulated heat in the warm pool? In other words, do the “events … counteracting the effects of the trailing La Niña” come from some dynamical process that provides a continuous source of energy, or is the energy simply a release of the energy previously accumulated in surface waters over the preceding ENSO phases? It sounds like you mean the latter, but I’d like to be sure. If it’s the case, did you compute if the amount of thermal energy in that pool might be sufficient to counteract the effects of the La Niña while SST might still remain quite high over the area of the warm pool?
Yes, Bob, I’m aware of both of those things, as I have been following your posts for a while. I have learned much about ENSO, PDO, and AMO, none of which discredit the fact that there may be a GHG forcing component in the warming of the oceans as a whole. Again you make this a black and white issue with your last question. I never said CO2 was driving anything. I said that it may be one component of the overall warming trend, possibly manifested by strong El Ninos.
You still aren’t answering any of my major concerns. Please stop using time-wasting tactics.
“If CO2 was driving the El Nino dominated period, why have NINO3.4 sea surface temperature anomalies turned back to La Nina conditions?”
Whether it is correct or not, there is a theory about this called the dynamical thermostat. See for example Clement et al. 1996, Journal of Climate. FWIW, paleoclimate reconstructions of Nino3.4 also seem to suggest an anticorrelation between the cold tongue and ~200-yr solar cycle (Emile-Geay et al 2013, also J. Climate). Also fwiw, the Hadley SSTs show 20th century warming everywhere except a piece of the North Atlantic and One effect of this is to increase the east-west temperature gradient on the equator which maybe could strengthen El Nino events. Still a *lot* of uncertainty in all this, and it’s fairly controversial even within the climate community (more researchers argue an opposite mechanism, in fact), but it is at least consistent.
BTW, my paper is 2003.
Hmm, that line should be “Also fwiw, the Hadley SSTs show 20th century warming everywhere except a piece of the North Atlantic and the cold tongue region.”