Incidentally, the over cooler tropical Pacific nicely explains (quantitatively — I’m not just speculating) why the rapid warming in Antarctica culminated with the 1990s and appears to have leveled off in the 2000s. Changes occurring in the tropics have truly global effects. See e.g. our paper in Nature Geoscience, 2013.
I generally agree with the point of view on the role of equatorial Pacific in so-called slowdown of global warming, but I have a question to Eric and Matthew: Is it possible that AMO may also contribute to the slowdown (at longer time scales) so that the slowdown may last longer than 15 years, for example, similar to the hiatus from 1940-1970s?
I’d analyzed the results from an equilibrium run in CCSM3 and it seems to me the AMO might contribute, but not in a running 11-yr-trend of global SAT.
[Response: It's certainly possible for the AMO to influence the global mean SAT trajectory. One of Jerry Meehl's recent hiatus papers demonstrates this in the NCAR model: it's secondary to the IPO/PDO in their study, but significant nonetheless. The key thing for me - in terms of identifying the ocean's role in the current SAT slowdown - is to identify regions where the heat uptake has accelerated. The oceans have sucked up around 93% of excess 'anthropogenic' heat in the past 50-100 years: and they've sucked up heat from the atmosphere in a big way over the past decade. But the question is, where has this accelerated since 2000 compared to the preceding decades? That led us to the western Pacific. - Matthew]
In 2009 Kyle Swanson told RC readers that his work with AA Tsonis indicated anthropogenic warming of the surface air temperature essentially stopped after the 1998 El Nino, roughly, and would not resume until 2020.
Much of their work is all about Pacific Ocean dynamics. The warming and cooling phases of the PDO are often characterized as being El Nino dominant (low westerly winds) and La Nina dominant (high westerly winds).
Why no credit?
[Response: Many authors have made the point about the Pacific playing a significant role. In his post on RealClimate, Swanson did not make a prediction warming "would not resume until 2020". He was making an illustrative point, explaining why we should perhaps not be surprised if we had to wait until about 2020 for the long term trend to be the same as the last 20-years trend. --eric]
What happens if the wind doesn’t abate? Shouldn’t there be an El Nino too at one point – when enough heat is accumulated? This could even mean a linear persistent El Nino mechanism cycle? Also what are the impacts to deep sea lifeforms and how deep does the heat penetrate – only 300 meters? It would be really interesting to see an assessment of cloud formation and convective mixing in regards to England et al and Sherwood et al.
[Response: Some heat gets fluxed into the Indian Ocean via the Indonesian Throughflow. We didn't study ecosystem impacts: but the ~4 degs C warming in the Western Pacific thermocline since the early 1990s would likely be having an impact.- Matthew]
Matthew, a humble editing suggestion you may like to consider is this:
“… the climate mechanics of the slowdown in the rate of increase in average global mean surface temperature (GMST) seen in the observations during 2001-2013.”
You said this: “… the climate mechanics of the slowdown in warming seen in the observations during 2001-2013….”
I believe the former is more scientifically accurate and clear. Plus far less likely to be misinterpreted and/or intentionally misused by others out of context to your actual meaning.
Co-incidentally Matthew, you said this in your introduction: “Over the last century, no single forcing agent is clearer than anthropogenic greenhouse gases,…”
Which is intimately related to a recent comment of mine on RC:
AR5-TS TFE.8: Climate Targets and Stabilization
The concept of stabilization is strongly linked to the ultimate objective of the UNFCCC, which is:
“to achieve […] stabilization of greenhouse gas concentrations in the
atmosphere at a level that would prevent dangerous anthropogenic
interference with the climate system.”
Recent policy discussions focused on limits to a global temperature increase, rather than to greenhouse gas concentrations, as climate targets in the context of the UNFCCC objectives. [end ar5 quote]
“NOTE – This shift in POLICY EMPHASIS from a GOAL based on GHG PPM CONCENTRATIONS to one of AVERAGE SURFACE TEMPERATURE (GMST) ‘appears’ to have been imposed onto the IPCC process by the most powerful National Governments in the UNFCCC.
“This change is NOT something instigated by the Climate Scientists and IPCC Authors themselves during the writing of the AR5 IPCC reports, nor does this appear based upon the scientific work in any of the published climate science Papers since the AR4 in 2007.” [...]
“NOTE: The last 5+ year emphasis by denier activists and recalcitrant anti-Science National Governments & Legislators has been on the idea of a HIATUS-PAUSE in TEMPERATURE INCREASES.
“Their OBJECTIVE (I believe) goes like this: There has been Nil to Minimal short-term Average Temperature Increase = UNFCCC Goals Are Being Met = NOT A PROBLEM = No Action Required = Nothing to see here.”
Eric Steig: ..rapid warming in Antarctica culminated with the 1990s and appears to have leveled off in the 2000s. Changes occurring in the tropics have truly global effects.
Doesn’t this also suggest that the temperature gradient in the Northern Hemisphere is further increased, hence contributes to the science around jet stream anomalies (Francis et al., Screen, Overland and more).
Eric, could you clarify something in your introduction: ‘increases the amount of heat stored in the upper few hundred meters of the ocean’
My understanding is that heat storage in the upper few hundred meters hasn’t increased much at all over the past decade. The observed change has been an increased proportion of heat accumulation occurring below 700m.
[Response: I was purposely vague here, I admit, because I haven't studied the issue carefully -- my original text said "upper 1000". You are right that the big news about this has been mostly about the heat gain below 700 m, but that still amounts to only about 30% -- see the Balmaseda et al. paper. --eric]
Would increased amounts of heat being taken into the oceans also indicate increased amounts of CO₂ being absorbed? Ie, if there’s more cold, old water accessible to take up heat would that also take up more CO₂?
[Response: Yes indeed. CO2 goes up and down with El Niño and La Niña events as well. CO2 is increasing so fast that it doesn't make a big difference though. The numbers are of order 10 GT/year fossil fuel emissions, vs. ! GT fluxes (which vary by around 50%) between El Niño and La Niña years. A randomly selected and perhaps not-very up to date write-up on this, by NOAA experts, is here http://www.pmel.noaa.gov/pubs/outstand/feel1868/text.shtml and has a bunch of good references if you want to follow up further --eric]
> 9 prokaryotes says: 18 Feb 2014 at 12:41 AM> Doesn’t this
> also suggest that the temperature gradient
> in the Northern Hemisphere is further increased, hence
> contributes to the science around jet stream anomalies
> (Francis et al., Screen, Overland and more).
No, you have that backward.
The temperature gradient decreases — becomes less steep — as
the Arctic area warms faster than the overall N. hemisphere.
Ars has an interview with Dr. Francis about this:
… the site of the jet stream—the border of the polar vortex—is set by a sharp boundary between cold Arctic air and the more moderate temperatures of the mid-latitudes. As the Arctic warms, that boundary becomes diffuse, and the jet stream is less likely to be pinned at the edge of the Arctic.
Thanks for covering this important topic. It is looking more and more likely that we are heading for an El Nino in the coming months/couple years (though it is still too early to be certain). Latest NOAA forecast is out, and it says…
[quote]models predict either ENSO-neutral or El Niño (greater or equal to
+0.5ºC) during the Northern Hemisphere summer 2014[/quote] (p. 26)
[quote]…El Niño starting in May-July 2014[/quote](p. 27)
Am I right in assuming that, even if this occurs, it will be too late to shed much moisture on CA and the rest of the parched West this year? What might the consequences be globally, especially if this turns into another major El Nino?
Another thing that we should keep in mind is that there has been the opposite of a deceleration in temperature trends if you just look at global temperatures on land, particularly if you look at the recent BEST data: http://www.woodfortrees.org/notes
(and what am I to make of reCaptcha’s “xport sho the”?)
[Response: Which of course makes the point once again that short-term trends don't tell you very much (notwithstanding England et al's very interesting and important analysis).--eric]
If the trade wind acceleration has led to an increased differential in the western Pacific sea height over that of the eastern Pacific, and an increased differential favoring ocean heat accumulation over surface and atmospheric warming, one would expect each of these phenomena to act as a brake on their further growth. What might be the result – would it imply mainly a return to more normal rates of surface warming, or would it be expressed as a temporary supernormal surface warming? I suspect a little of both, but I would be interested in further empirical or model evidence, including a consideration of the timescales that are likely to be involved.
Comment by Rafael Molina Navas, Madrid — 18 Feb 2014 @ 4:06 PM
Thanks very much for this post. It is just the topic I wanted to see.
Regarding surface air temps vs ENSO, John n-g already graphed El Niño, neutral and La Niña years and the three trend lines are very close to parallel. If these trends continue, then as soon as La Niña catches up with the big El Niño of ’98 surface air temperature will go up with the slope of those lines even without another El Niño.
[Response: Yes, that was a great post by John N-G. Two great lines at the end summarize the point:
So about that lack of warming: Yes, it’s real. You can thank La Niña.
As for whether this means that Tyndall gases are no longer having an impact: Nice try.
Comment by Pete Dunkelberg — 18 Feb 2014 @ 4:35 PM
For a look at global circulation, hop on over to Steve’s place.
Comment by Pete Dunkelberg — 18 Feb 2014 @ 5:05 PM
It would be interesting to see if the shipping records of the China Trade ( a surprisingly well archived subject ) hold any useful infromation about decadal variations in the trans-pacific trade winds , which might lead to reconstruction of patterns attributable to El Nino and ENSO.
A journal called The American Neptune specializes in the history of 19th century navigation .
Re Hank #14, sorry if i wasn’t very clear – and i think Francis is only referring to the horizontal “thickness” or temperature gradient, not the vertical distribution (which i meant) and ripple effects from jet anomalies.
From #9 – I quoted Eric’s statement on Antarctica “Changes occurring in the tropics have truly global effects.” and commented “Doesn’t this also suggest that the temperature gradient in the Northern Hemisphere is further increased, hence contributes to the science around jet stream anomalies.”
From the recent Met Office release The Recent Storms and Floods in the UK which makes a great read, however they do not address sea ice loss, what i don’t understand, since there is a lot science already – even if still heavily studied.
During December and January 2013/14 the pattern of winds over the North East Pacific and North America was very disturbed (Figure 13, right panels). The North Pacific jet was deflected a long way north, with a secondary branch extending southwards into the tropical Pacific accentuating the separation of the Pacific and Atlantic jet streams. The effects of this over North America and into the North Atlantic were profound.
The deflection of the jet to the north led to colder air being carried south over Canada and the northern US (as seen in Figure 13) to enter the North Atlantic jet and establish a stronger than normal temperature gradient at the entrance of the North Atlantic Jet. This acted to strengthen the jet and provide the conditions for active cyclogenesis, which in turn led to a sequence of strong storms across the UK throughout December and January. As Figure 13 indicates, the North Atlantic jet was, on average, as much as 30% stronger than normal. Similar, but weaker, conditions can be seen in the southern hemisphere, mirroring those to the north and supporting the view that the tropics were driving at least some of what has been experienced this winter.
The polar jet stream is then deflected a long way south over the US bringing cold air with it It is well understood that El Nino and its cold counterpart La Nina have major effects on weather patterns around the globe. Indeed the changes in the jet stream over the North Pacific, described above, are typical of what is observed during La Nina events (Figure 15), with the jet being deflected to the north by anomalously high pressure off the western seaboard of the US, and with a variable jet to the south along which disturbed weather forms.
The polar jet stream is then deflected a long way south over the US bringing cold air with it In the North Atlantic, ocean temperatures continue to be above normal near 300N which would also contribute to a strengthened north-south temperature gradient across the storm track, aiding the development of storms. As Figure 16 shows, the sub-tropical Atlantic is currently warmer than the average for the last 30 years (1981-2010), but substantially warmer than it was 30 years prior to that (1951-1980).
This in itself will potentially increase the moisture being held in the atmosphere, above the ocean, and entering the storm systems as they moved towards the UK. In terms of the global influences of El Nino/La Nina, it is the changes in tropical rainfall patterns that ultimately drive the perturbations to the atmospheric circulation described by Figure 15. So whilst the sea surface temperatures suggest neutral conditions in the tropical East Pacific, it seems that tropical rainfall patterns in December and January are consistent with a La Nina signal, with higher than normal rainfall over the West Pacific, Indonesia and the eastern Indian Ocean throughout December and January (Figure 17). Bearing in mind that the average rainfall in this region is between 8 and 12 mm/day, these anomalies in rainfall are substantial. Page 15
Over the last 3 years there have been major advances in Met Office capabilities in simulating weather and climate variability20; for example, the climate model (HadGEM3) is now able to simulate the frequency of atmospheric blocking in the Atlantic that agrees with observations. These advances have come primarily through increased horizontal resolution (from typically 150km in the atmosphere and 10 in the ocean, to 60km and 1/40 respectively) and increased vertical resolution (from 38 levels in the atmosphere and 40 levels in the ocean, to 85 levels and 75 levels respectively). This has facilitated substantial progress to be made in simulating and understanding the processes that determine the natural variability of the climate system (such as the North Atlantic Oscillation (NAO) and El Nino/La Nina and its global influences), and its response to factors such as solar variability and declining Arctic sea ice.
With a credible modeling system in place it should now be possible to perform scientifically robust assessments of changes in storminess, the degree to which they are related to natural variability and the degree to which there is a contribution from human-induced climate change. These studies are a high priority, although they are very computationally-intensive and require simulation of many decades of the climate to ensure a statistically significant result. Page 24
I meant to write “Francis is only referring to the vertical “thickness” or temperature gradient, not necessarily the horizontal distribution” -which comes from changes in the jet. That’s at least my take away when she says the evaporation is weakening the 500mb layer.
Does the subducted heat get mixed away before this can resurface, or does the heat find a way to return to the surface when the winds reverse?
I’ve heard this a few times and am unsure what the putative mechanisms are for this heat transfer. Is it really that heat is transferring out of the ocean into the surface air, or that transfer of heat into the ocean slows down, which leaves more heat at the surface? Or something else?
[Response: It will be a combination of both. The longer the wind trends persist the more chance we have of the increased heat uptake being mixed to deeper depths. If the winds abate sooner, more heat can return to the surface faster, as less heat has been buried deep by mixing. - Matthew]
A vigorous spectrum of interdecadal internal variability presents numerous challenges to our current understanding of the climate. First, it suggests that climate models in general still have difficulty reproducing the magnitude and spatiotemporal patterns of internal variability necessary to capture the observed character of the 20th century climate trajectory. Presumably, this is due primarily to deficiencies in ocean dynamics. Moving toward higher resolution, eddy resolving oceanic models should help reduce this deficiency. Second, theoretical arguments suggest that a more variable climate is a more sensitive climate to imposed forcings (13). Viewed in this light, the lack of modeled compared to observed interdecadal variability (Fig. 2B) may indicate that current models underestimate climate sensitivity. Finally, the presence of vigorous climate variability presents significant challenges to near-term climate prediction (25, 26), leaving open the possibility of steady or even declining global mean surface temperatures over the next several decades that could present a significant empirical obstacle to the implementation of policies directed at reducing greenhouse gas emissions (27). However, global warming could likewise suddenly and without any ostensive cause accelerate due to internal variability. To paraphrase C. S. Lewis, the climate system appears wild, and may continue to hold many surprises if pressed.
We thank Isaac Held and Lord Robert May for helpful comments on earlier versions of the manuscript.
“Swanson called it a pause in warming, and he was saying it could last until 2020.”
You first said he said it WOULD last until 2020 …
“In 2009 Kyle Swanson told RC readers that his work with AA Tsonis indicated anthropogenic warming of the surface air temperature essentially stopped after the 1998 El Nino, roughly, and WOULD NOT RESUME UNTIL 2020″
Big difference. HUGE difference, actually.
And your quote also says it could turn out to be the opposite:
“However, global warming could likewise suddenly and without any ostensive cause accelerate due to internal variability.”
This makes it even more clear that he was not predicting we’d see a pause until 2020. He’s saying, in essence, you can flip a coin, because currently it is impossible to predict with any precision in advance when natural variability will cause temps to uptick or downtick.
In other words, Eric’s inline response to you:
“Swanson did not make a prediction warming “would not resume until 2020″. He was making an illustrative point, explaining why we should perhaps not be surprised if we had to wait until about 2020 for the long term trend to be the same as the last 20-years trend”
Fairly summarizes the point Swanson was making.
It is unclear to me why you’re continuing to flog this dead horse.
It seems to me there’s an easy way to destroy the basis of the argument about a “slowdown” in the climate system:
1. Some people say that global warming is not taking place because there has been a slowdown for the last few years in the increase of surface temperatures.
2. The same people do not deny that, in the geological past, there have been periods of natural warming; on the contrary, they use that fact in order to say that climate fluctuations are something natural.
3. As a result, they do not deny that there has been a warming curve of surface temperatures, about 10 000 years ago, that led to today’s warm period.
4. If data show that that warming curve was not neatly regular, but that there were “slowdowns” in it, then their argument explodes, because these slowdowns didn’t change anything to the end-result, ie. today’s warm period and its increase of 5° C in mean temperature.
Can anybody tell if the above makes sense, and whether it’s already been developped, and if so, which data about the last deglaciation could be used?
PS: I am putting aside the reevaluation of surface temperatures, the energy that has gone into heating oceans, etc., in order to concentrate on the hollowness of the argument itself.
Comment by Pierre-Emmanuel Neurorh — 19 Feb 2014 @ 11:57 AM
JCH is quoting from the 2009 paper. Note that “pause in warming” there doesn’t mean a pause in warming the planet; it means a pause in the perceived surface temperature where we live.
Think of the playground game “crack the whip” — pauses, and surprises.
“Even if the excess heat fluxed into the ocean were longer-term, burying the heat deep in the ocean would not come without its consequences; ocean thermal expansion translates this directly into sea-level rise.”
The coefficient of expansion of ocean water at a depth of 1000 meters is half that of the tropical surface.
It seems to me the practical implication of this study is that we should be producing all of the energy we can from an ocean thermal energy conversion system that moves heat to this depth.
Thank you for that manuscript. The role of the oceans tends to be under-appreciated in climate models. Much of the “pause” and previous warming could be just internal variablility associated with ocean dynamics.
I have a question about the sea level rise (the lower left figure in the group of four, fist image): Is this sea level change “on top of the global average” or is it the absolute values including all factors? The reason I ask is I live in HI and I’ve seen some substantial changes in some of our beaches in the last 30 years with the biggest effects of erosion occurring during a period about 10 to 15 years ago with some leveling off somewhat over the last 5 to 10. The figure seems to indicate (current?) stability in sea level for HI (light blue to white). If this buildup to in water in the Western Pacific were to change and reverse direction, I should expect to see a change (return? increase?) in the same erosion patterns — if that erosion is caused by sea level rise (which is the only explanation anyone here can give). Your comments would be welcome.
Thank you Dr England for a fascinating post and paper.
Can you explain how you constructed Fig 5 (the model observation comparison). It seems to show a similar discrepancy between IPCC projections and observations as the (apparently flawed) draft AR 5 Fig. 1.4, in contrast to the final version of AR 5 fig 1.4, which suggests recent temperatures are in line with projections – https://www.skepticalscience.com/curry-mcintyre-resist-ipcc-model-accuracy.html
I will admit to a certain prejudice- but I do think the ocean will eventually get it’s way. In support, my colleagues try to persuade me that, over the past couple billion years, the oxygen level in the air has been determined dominantly by the life in the oceans. My best guess is that it might be a mistake to ignore 70% of the planet’s surface.
Water driven across the Pacific reaches the Maritime Continent. It is warm. The ‘continent” slows it down. The rain from water that evaporates from the warm Pacific blows on ahead. The warm water left behind becomes dense with salt. The dense water sinks and may become entrained in cold north-south currents. The PIG melts from below.
Comment by Pete Dunkelberg — 19 Feb 2014 @ 11:52 PM
Sorry, perhaps the wrong time and place to ask but, do any findings of atmospheric water vapor from NVAP-M shed any light (or any doubt?) on the “slowdown”? Or, in general, anything concerning feedbacks, warming and model projections?
England et al. show that this increased ocean heat uptake — which has occurred mostly in the tropical Pacific — is associated with an anomalous strengthening of the trade winds.
When the phase of the Arctic oscillation (AO) is warm, trade winds are stronger within the tropics. The cold phase of the AO leads to weaker trade winds. Link and Link
Maybe the trade winds are stronger because of the increased Arctic sea ice cover, variability.
The strengthening relationship between Arctic Oscillation and ENSO after the mid-1990s The Arctic Oscillation (AO) and ENSO have dominant influences on the extratropical and tropical climate variabilities in the Northern Hemisphere, respectively. In this paper, we document a strengthening of the AO–ENSO relationship in January after the mid-1990s, when the interannual variability of the previous September Arctic sea ice cover (ASIC) had consistently increased, by analyzing the AO, ENSO, and associated atmosphere–ocean variability. Our analysis further suggests that the larger ASIC interannual variability may account for the larger scale wave train across the Pacific basin, and the AO is strongly coupled to the circulation in the North Pacific. The strengthened connection between the −AO and Aleutian Low (AL) may contribute to the identified closer relationship between the −AO and ENSO. Link
Hank – it’s not a game. The definition of global warming is the surface air temperature. If it goes up, we have global warming; if it stays flat, we have a pause in global warming; if it goes down, we have global cooling.
[Response: I am well aware that temperature is a different quantity than heat, and have no objection to people tracking the accumulation of heat, but 'global warming' is simply not defined in this way. This is not a 'fundamental disagreement', this is simply you redefining the term 'global warming'. For me (and almost anyone else you care to ask) global warming refers to the increase in global surface temperature anomaly. Indeed, 'warmth' is not a pure function of Joules - ice and water at 0 deg C have the same 'warmth', but very different heat contents. The very natural definition of warming is in terms of temperature; when people say that something has warmed, it means that the temperature has risen. You would be much more effective at communicating your scientific points if you used words in ways other people were already used to. - gavin] …
You make judgements with no knowledge of what say. I commonly tell skeptics at Climate Etc. that people can draw fairly long flat lines, even descending lines, in the SAT data. It’s obvious that can be done. Then I tell them they would really have something if the oceans were also cooling, which they aren’t.
Dan H. – wrt to post-1970s warming, I do not agree with you, and I do not think the authors agree with you:
Finally, a fraction of the post-1970s warming also appears to be attributable to natural variability. – Tsonis and Swanson
To me “a fraction” denotes a small amount. If you look at their graph, fig 4, their analysis finds natural variability played a small part in the post-1970s warming. Others may disagree with my interpretation of the graph.
Gavin: Sorry, i can´t fully understand your response …
Natural definition of warming, OK. But I think it´s not sufficient to say:
“…have no objection to people tracking the accumulation of heat …”.
If, f.e., a lot of energy accumulated in water that melts, during several years, with no temperature increase, and rest of planet maintained mean temperature, skeptics would say global warming had stopped … They could be considered right, but the global warming “problem” wouldn´t have dissapeared …
Comment by Rafael Molina Navas, Madrid — 20 Feb 2014 @ 7:31 AM
Re- Comment by Pierre-Emmanuel Neurorh — 19 Feb 2014 @ 11:57 AM
Hank @31, thanks. That makes it sound like I was more confused than I thought.
My question, thinking more clearly, came down to asking whether the ocean is warmer or cooler than the atmosphere — so is El Nino / reduced trade winds going to cause heat flux from ocean to atmosphere, or merely reduced heat flux from atmosphere to ocean (either way, the atmosphere gets warmer). I was reading “the heat will come back up” as meaning a heat flux from ocean to atmosphere.
But it seems like I was just barking up the wrong tree, and this is not what the interesting scientific question is… I’ll need to read more to understand this.
First, the Swanson, et. al. paper, to which you linked, has no fig. 4. Their paper firmly states, “This result is another link in a growing chain of evidence that internal climate variability played leading order role in the trajectory of 20th century global mean surface temperature.” The word “fraction” is an ambiquous term, and cannot be assigned a definitive value in this report, except to say less than the whole. (remember 1/2 and 3/4 are also fractions). My term “much” is just as ambiguous, and chosen based on their statements. Even their penultimate statement that surface temperatures could decline or accelerate over the next several decades suggests higher than “small amount” attributed to natural variability. I can see how these results could be interpretted in many different ways though.
You may wish to read the paper to which JCH linked in #30. The recent slowdown may just be natural variability. Also, I think your #4 has a typo, unless you are referring to the temperature increase since the end of the last ice age.
JCH at 43 – The skepticalsience article, Where is global warming going? – http://www.skepticalscience.com/Where-is-global-warming-going.htm – graphs IPCC data to show that only 2.3 percent of global warming is going into the atmosphere. Ninety-three percent is going into the oceans and there appears to be broad agreement it will take as much as 1000 years for this heat to equilibrate with the atmosphere. The 2012 paper, World Ocean Heat Content and Thermosteric Sea Level change (0-2000 m),1955-2010, by Levitus et al. points to the fact that over the study’s span, to a depth of 2000 meters, the oceans have warmed on average only 0.09 C but if all of that heat was instantaneously transferred to the lower 10 kilometers of the atmosphere, it would warm on average 36 C.
The average depth of the oceans is 4267 meters so the deep has a great capacity to absorb heat that would do us in if if it was in the atmosphere or cause us considerable problems in the upper reaches of the ocean.
The second law of thermodynamics dictates we can generate work by moving heat from the surface into the available cold heat sink.
Comment by Rafael Molina Navas, Madrid — 21 Feb 2014 @ 3:18 AM
Dan H @50.
If you were a bit more thoughtful, you would note that figure 3 of Swanson et al 2009 shows about a third of the post-1980 warming is being attributed by the paper to “natural modes of variability internal to the climate system.” Thus it fits with other works of wigglology. For me. the one word in the paper that jumps out and does a little dance is the word “hidden”. This one word speaks volumes about the world view of the authors.
While the denialist fraternity shout with joy at the appearance of such papers (for instance, note the provider of the 2007 paper’s PDF for google scholar), the work is at the end of the day nought but curve-fitting. Swanson & Tsonis (2009) is rightfully written in less definite language “This suggests that a break in the global mean temperature trend from the consistent warming over the 1976/77–2001/02 period may have occurred.”
Despite all the denialist hurrahs, all such studies as this fail to fit their work into climatology proper. They trumpet that they have “solved” the early 20th century warming leaving a nice smooth forcing that they helpfully attribute to anthropogenic causes. But is the anthropogenic forcing going to be such a nice oh-so-smooth curve? These studies write in some magical wiggle and silently airbrush out the likes of sulphur dioxide. This is not new work, yet it cannot get past the ‘first paper’ status. Thus I brand it ‘curve-fitting’ and ‘wigglology’.
#52 Thanks Ken,
I think England et al are using a fine approach. The characteristic that we should be monitoring is the free energy of the system. That includes heat, kinetic energy (wind, pressure), latent energy, and imparted forcing energy terms including changes in potential energy. The free energy is partitioned between these contributions and these contributions can shift over time, with the sum showing a secular near-monotonic trend once all the fluctuating terms are accounted for and balanced. This approach is often referred to as variational principles in thermodynamics, see recent work by W Muschik, P Ván, C Papenfuss.
England’s work is clearly showing how missing thermal energy can be compensated in excess wind energy. Same goes for pressure in the SOI measurement, think in terms of the ideal gas law.
The CSALT model is a case where I put everything in the hopper and see what pops out. The biggest fault that I have seen skeptics make of the model is that it is overfitting. I have no problem with that — even if it is not doing the factor accounting perfectly, it makes a great heuristic.
33. Deniers point to the recent so called pause in global temperature increases as proof there is no global warming. There are other instances of apparent pauses in the last couple of hundred years. And yet, looking at these periods in hindsight refutes the idea that these periods proved that there has been no warming.
It is simply invalid to be in the midst of a short period of time and then use that current period of time as a proof against global warming given the historical data and ups and downs in temperature that we have.
I don’t think you have to go back 10,000 years to demonstrate how wrong the deniers arguments are. On the other hand, for the vast majority of people you are dealing with, arguments don’t matter, logical or otherwise.
In any event, deniers will you your data to argue that we don’t need CO2 to get the warming you speak of.
The ‘pause’ debate seems to boil down to: ‘it didn’t warm when I/they/it wanted, where I/they/it wanted, or at the rate I/they/it wanted’, followed by pro-pollutionists throwing another raw data grenade (actual or invented) into the middle of the research.
The pro-pollutionists present ENSO and the Flat Temperature Society as: http://ggweather.com/enso/oni.htm .
The research’s cleanest observation graph (no butterup intended) of ENSO and the Great Warming is: http://www.realclimate.org/images/climcent_sat_enso.png
The clarity revealed in the RC graph reduces a debate about pause to the nail-head years – ’06, ’08, and ’09. Well, giddyup that. The clarity also reveals the underlying warning about the warming – the climate system is relying on El Nino’s for global cooling – and that influence is failing.
[Response: Relying on La Nina's you mean. "Flat Temperature Society" -- I love it! --eric]
Very interest post, and certainly covers all the likely causes of the flattening of the rise in tropospheric temperatures over the past decade or so. Some thoughts:
At a recent workshop with the APS, Santer strongly suggested (and presented slides to the effect) that the impact of volcanic aerosols over the past 10-15 years might be larger than anyone has thought, owing to a series of moderate volcanic events. There has been a definite measure increase in stratospheric optical depth as a result of these. Santer seemed to suggest a paper on this might be forthcoming.
Related to heat going into the oceans, there are many related effects, not just the fact that the tropospheric sensible heat might not rise as fast during such a period. Namely: Increase in the overall size and energy levels of the IPWP, which has effects on overall tropospheric/stratospheric/mesospheric circulation patterns as this additional energy in the IPWP (which has been rising since the 1950′s on a decadal basis) has global effects. Additionally, the rising OHC globally has lead to a greater measured advection of energy toward the north pole via ocean currents, and this has allowed for the decrease in net sea ice. Of course this energy finds its way out of the ocean to cause general tropopshere warming in the polar region and melting of permafrost, etc. Hence, the Cowtan & Way’s approach helps to “recapture” some of this increase in advected energy from the equator to the pole.
“IPWP?” I am concerned that you are so busy that you are unable to type “International Parliamentarians for West Papua,” the most amusing of two meanings for your acronym in acronymfinder.com. People not familiar with climate science come here to learn something. This is one of the goals of this site.
[Response: Indo-Pacific Warm Pool. Yes, acronyms are overused. It takes me less time to type Indo-Pacific Warm Pool than IPWP because it uses words that my fingers "know", while IPPW -- see there you go, I mis-typed it! -- does not. Of course, this doesn't necessarily help much. Gates's reference to "Increase in the overall size and energy levels of the IPWP" isn't really an explanation -- it's more just a description of what has been observed (though I'm not sure what he means by "energy levels". --eric]
I think there is so much more to discover. I have long held the view that global temperatures have been suppressed by the a nodal rise in atmospheric moisture. Moisture has the effect of absorbing energy at the surface and transporting it vertically. The more intense energy flows are increasing the air circlation in the Hadley cells possibly to the extent that Brian Farrel’s theory is playing out at least in part in the Northern Hemisphere. So the combination of air mass overflow into the Arctic pressure cell coupled with the confusing dynamics of the Atlantic conveyor we are seeing seemingly contradictory weather effects in the upper northern hemisphere.
Another thing that I have noticed is there seems to be some synchronicity between massive weather events in the western European field and Australia. Hard to make an argument to support that until I downloaded a weather app Weer en Verkeer which makes available a lot more global weather information in animated form. A month ago the Australian moisture display appeared to be showing a huge amount of moisture crossing the equator over the Phillipines and moving into the Northern Hemisphere weather systems. If this is what I saw then indeed there is a mechanism to possibly cause seemingly synchronised weather events diagonally opposed in seperate hemispheres.
I think that there is so much that ee don’t know and yet the US is moving the to reduce research funding in many fields of science.
Speaking of acronym confusion, I was at a meeting the other day where someone talked about performance tuning a big atmospheric model with support in part from the IPCC. No not that one, the Intel Parallel Computing Center.
The recent slowdown of global warming is a consequence of both a slowdown in the growth rate of climate forcings and recent ENSO history. Given that the tropical Pacific seems to be moving toward the next El Niño, record global temperature is likely in the near term. However, the rate of future warming will depend upon changes of the tropospheric aerosol forcing, which is highly uncertain and unmeasured. http://www.columbia.edu/~jeh1/mailings/2014/20140121_Temperature2013.pdf
Dr. Ricky Rood at WU agrees with the general idea of tracking all of the constituent energy factors:
“However, the heat being accumulated does not have to go only to increasing the average surface temperature. Some of that heat has been melting glaciers, sea ice and ice sheets. Much of that heat has been heating the ocean, causing it to expand and raising sea level. Energy goes into motions in the atmosphere and ocean. ”
If the oceans is absorbing the heat, then does that therefore cause the oceans to produce more evaporation which in turn should have a greater cooling affect? This apparently occurs with trees. More co2 should also cause a greater increase in all vegetation as CO2 is what plants live on, cooling the planet even more. http://carnegiescience.edu/news/water_evaporated_trees_cools_global_climate.
Has this been factored in?
England notes that “Even if the excess heat fluxed into the ocean were longer-term, burying the heat deep in the ocean would not come without its consequences; ocean thermal expansion translates this directly into sea-level rise, with Western Pacific Island nations already acutely aware of this from the recent trends.”
How does the direct effect of thermal expansion due to increased ocean heat storage square with rates of sea-level change over the period of the so-called “hiatus”?
According to satellite data compiled by the CU Sea Level Research Group, sea levels have risen with a tightly linear trend of about 3.2 mm/a since 1992. We know that over that same time period, influx of meltwater from Greenland and the Antarctic has increased in rate, and obviously we also know that atmospheric CO2 forcing has increased steadily, with a slightly concave up curve, over that period as well, thanks to anthropogenic emissions.
My question is, given that influx of meltwater has steadily increased in rate, and given that CO2 forcing has increased (in a warming climate system already out of equilibrium), why has there not been any increase in the rate of sea level rise since the “hiatus” began?
If anything, the facts would seem to logically indicate a slowdown of ocean heat uptake and its concomitant effect of thermal expansion, offsetting in equal proportion the increase in volume due to increased meltwater, resulting in the observed linear sea level trend.
Is this due perhaps to increased reservoir impoundment from new dams such as the massive Three Gorges dam in China? That seems ostensibly plausible, but despite that project, at least according to hydroclimatologist Peter Gleick of the Pacific Insitute global reservoir storage has slowed and leveled off over the the period of time corresponding to the “hiatus”. And we must also consider the fact that humans have been hastily emptying the world’s deep aquifers of fossil water, which ultimately ends up in the oceans.
In a nutshell, how is it possible that all the extra heat from greenhouse warming is going into the oceans, alongside increasing rates of meltwater, yet the rate of global sea level rise has remained essentially constant since 1992, well before the onset of the “hiatus”?
Raising SSTs might increase evaporation a bit, but what about wind fields, atmospheric pressure and air temperature (which of course affects relative humidity)? For a trustworthy projection, all of that (and more) would have to be quantified.
And that’s leaving out the fact that the heat going into the ocean is not necessarily raising surface temps. In fact, the process described in the post above “bring[s] cold deeper waters to the surface…”, which is why La Ninas *lower* global mean SST (and indeed global mean temp generally.)
Nick Nanny 76: “How does the direct effect of thermal expansion due to increased ocean heat storage square with rates of sea-level change over the period of the so-called “hiatus”?”
Perhaps my comment at 35 has some relevance to this. Péter Berényi posted a plot of the Volumetric thermal expansion coefficient of ocean water as a function of depth at https://skepticalscience.com/news.php?n=273&p=2 (comment 53). As you point out Greenland and the Antarctic melting has increased since 1992. Heat flows from hot to cold regions, thus from the tropics to the poles aided by tropical storms. Moving surface heat mechanically from the tropical ocean surface into the largest cold sink on the planet (which appears to be happening naturally in any event) enables you to produce power even as you sap the strength of tropical storms and perhaps slow sea level rise?
when three atmospheric patterns came together over the Indian and Pacific oceans, they drove so much precipitation over Australia in 2010 and 2011 that the world’s ocean levels dropped measurably. Unlike other continents, the soils and topography of Australia prevent almost all of its precipitation from running off into the ocean.
The 2010-11 event temporarily halted a long-term trend of rising sea levels caused by higher temperatures and melting ice sheets.
Now that the atmospheric patterns have snapped back and more rain is falling over tropical oceans, the seas are rising again. In fact, with Australia in a major drought, they are rising faster than before.
“It’s a beautiful illustration of how complicated our climate system is,” says NCAR scientist John Fasullo, the lead author of the study. “The smallest continent in the world can affect sea level worldwide. Its influence is so strong that it can temporarily overcome the background trend of rising sea levels that we see with climate change.”
and ensuing discussion. Briefly: I suspect that heat is lately being subducted to deeper ocean, resulting in less thermosteric SLR since expansion coefficients are smaller for colder water; this decrease is masked by increased melt from ice sheets.
Just a little call out on the third figure above (which is based on Figure 5a in the paper). The figure is constructed by tying all the AR4+AR5 projections to the GISTEMP 5-year running mean for 2000. Because the year 2000 5-year mean was on the high side of the noise band* (it includes 1998), that naturally makes the subsequent projections appear to run high.
A fairer chart maker might have attached the model projections to a trend estimate for 2000. The choice made appears to exaggerate the premise of the paper.
(* Of course, one person’s noise is another’s signal. I guess Prof England would say that the 2000 5-year mean is mostly signal.)
The “Adjusted GCMs” are left tied to year 2000 trailing 5-year mean (because they are intended to track oceanic effects), while the IPCC models are tied to the long term linear trend at 2000 (because they cannot know about the year 2000 positive “oceanic” offset).
Nick Manny – “In a nutshell, how is it possible that all the extra heat from greenhouse warming is going into the oceans, alongside increasing rates of meltwater, yet the rate of global sea level rise has remained essentially constant since 1992, well before the onset of the “hiatus”?”
Recent sea level rise (SLR) hasn’t been constant, there was a large increase in ocean heat uptake (the thermal expansion component of SLR) in the early 2000′s followed by a slower rate thereafter. This probably the most obvious feature of the recent trend in ocean heat uptake shown in the Hiroshima widget. This has been briefly covered in a handful of recent papers of sea level rise – see for instance: Ablain et al (2009) – A new assessment of the error budget of global mean sea level rate estimated by satellite altimetry over 1993–2008, who state:
“These new calculations highlight a reduction in the rate of sea level rise since 2005, by ∼2 mm/yr. This represents a 60%reduction compared to the 3.3 mm/yr sea level rise (glacial isostatic adjustment correction applied) measured between 1993 and 2005. Since November 2005, MSL is accurately measured by a single satellite, Jason-1. However the error analysis performed here indicates that the recent reduction in MSL rate is real.”
Some complicating factors are the multi-decadal variation in continental water storage – the land stores more water during La Nina-dominant (negative IPO) periods, water impoundment on land, water extraction on land, and cabbelling. Cabbelling is the reduction in volume when two parts of water become well-mixed. So if you imagine a large fish tank with warm water at the top and cooler water below, the two layers become stratified (separated). If you physically mix these two layers, the total volume they occupy actually decreases.
I’ve yet to see a research paper on the topic, but cabbelling in tandem with the greenhouse gas-forced warming of the oceans and the IPO phase might be part of the solution to closing the sea level budget. The anomalously strong trade wind-forcing means stronger vertical and horizontal (Ekman)transport in the ocean. By removing warm water from the surface of the tropics and mixing it down into the (cooler) deeper ocean, the spin-up of the wind-driven ocean circulation may be providing a (probably small) counter-acting response to global sea level rise.
If this is in fact a real consideration, then we may see a larger-than-expected rise in global sea level when the IPO moves back to its positive phase. When the trade winds weaken, the wind-driven export of near-surface water out of the tropical ocean will slow down, as will the vertical transport of warm surface water down into the ocean interior. The surface ocean should warm quickly and, with greater thermal expansion in the warmer surface layers of the tropics, we could see a greater contribution from thermal expansion in positive IPO phases moving forward in time – assuming the large-scale ocean and atmospheric circulation themselves don’t undergo any significant changes.
There are lots of theories about the apparent pause in temperature increase. From the article, the theories in total add up to more than the discrepancies between the models and actual temperatures.
How will we determine which theory is right, and how long will that take?
What theory? There are a few possibilities. You can sift through the research and draw some conclusions, you can observe and add things up ie if averaged peak temperatures stay stable but oceans continue to heat, glaciers continue to retreat, polar caps continue to recede, atmospheric moisture continues to increase, weather intensity continues to rise, etc…then obviously there is more energy in the environment, or you can just sit back and wait for thirty years. In the end it will be obvious, one way or another, and you can then muse to yourself “why didn’t I see that sooner!”.
#74 Mark 5 says:
“More co2 should also cause a greater increase in all vegetation as CO2 is what plants live on, cooling the planet even more”
That possible negative feedback has been overestimated by many people, even by some scientists.
Plants also need nutrients from soil, and WATER. Those limit yield in many, many places.
To save water, that evaporates at stomata, these usually partialy close if CO2 concentration increases. They don´t need to be so open to get the CO2 they actually need …
Comment by Rafael Molina Navas, Madrid — 28 Feb 2014 @ 1:26 PM
#76 Nick Manny wonders:
“…how is it possible that all the extra heat from greenhouse warming is going into the oceans, alongside increasing rates of meltwater, yet the rate of global sea level rise has remained essentially constant since 1992, well before the onset of the “hiatus”?”
Many people think the hiatus is many years “old”. Two decade, or at least 15 year old …
Not at all … It is actually only three years old, too short a period to produce what you mention it should.
Following list, taken from NASA, shows “sliding” decades, and corresponding temperature changes:
Apart from the decade starting in the exceptional year of 1998, ONLY last thee ending in 2011, 2012 and 2013 show no clear warming.
Comment by Rafael Molina Navas, Madrid — 28 Feb 2014 @ 1:52 PM
I am thinking that the increased wind energy is more of a compensating factor than the claim of increased volcanic activity as proposed by Santer and others recently.
Be careful with your statistics. Whenever you started with a cold year (1997, 2000, 2001), your trend was high, and when you started with a warm year (1998, 2002, 2003), your trend was low. Similar results occur when you end with a warm (2010) or cold (2012) year. Over short timeframes, the trends can be heavily influences by one or two datapoints, especially if they occur at the endpoints. If you are adament about usign 10-year timeframes, it would be best to plot 10-year averages, and examine that trend.
Naive question perhaps: could the pause be similar to the way the temp of ice doesn’t move while it is melting? It is still absorbing heat as before, but the phase transition leaves temperature constant until the water is fully liquid.
The polar ice seems to be melting a good deal faster than anticipated over about the period of the “pause”. Could the extra heat absorption from faster melting account for the slower overall rise in average global temperatures?
Hi all. Question: What does it mean to say that the pause or slowdown is not significant? What if we flipped it and said there has been no significant warming, as we often see. Are those statements equivalent? I’m struggling with what it means to say a non-change is not significant, ascribing significance to a null.