Warming since 1950s partly caused by El Niño
HUNTSVILLE, Ala. (Nov. 11, 2013) – A natural shift to stronger warm El Niño events in the Pacific Ocean might be responsible for a substantial portion of the global warming recorded during the past 50 years, according to new research at The University of Alabama in Huntsville (UAH).
“Our modeling shows that natural climate cycles explain at least part of the ocean warming we’ve seen since the 1950s,” said Dr. Roy Spencer, a principal research scientist in UAH’s Earth System Science Center and the new study’s lead author. “But we also found that because the globe has had more frequent La Niña cooling events in the past ten or fifteen years, they are canceling out some of the effects of global warming.”
The paper detailing this research, “The Role of ENSO in Global Ocean Temperature Changes During 1955-2011 Simulated with a 1D Climate Model,” is scheduled for publication in the Asia-Pacific Journal of Atmospheric Science, and is available online at:
http://link.springer.com/article/10.1007/s13143-014-0011-z.
The results also suggest the world will warm by 1.3 C (about 2.34° F) from a doubling of atmospheric CO2, which is only one-half of the warming expected by most climate researchers.
General circulation climate models — such as those used to forecast global climate change — do not reproduce the tendency toward 30 year periods of stronger El Niño or La Niña activity, as are seen in nature.
Spencer and co-author Dr. Danny Braswell used all of the usual climate modeling forcings — including carbon dioxide and other greenhouse gas enrichment — in their study, but also plugged the observed history of El Niño ocean warming and La Niña ocean cooling events into their model to calculate the 61-year change in global ocean temperature averages from the sea surface to a depth of 2,000 meters.
“We used the observed ENSO (El Niño Southern Oscillation) history since the 1950s as a pseudo forcing factor of the model,” Spencer said.
When they ran their ocean model without ENSO, they arrived at the same general conclusions as the more complex general circulation climate models. When they added data from past El Niño and La Niña events as only a change in ocean mixing, the model indicated a climate system that is slightly less sensitive to CO2-induced warming than has been believed.
But the biggest change was when the model was allowed to change cloud cover with El Niño and La Niña in the same way as has been observed from satellites. The results suggest that these natural climate cycles change the total amount of energy received from the sun, providing a natural warming and cooling mechanism of the surface and deep ocean on multi-decadal time scales.
“As a result, because as much as 50% of the warming since the 1970s could be attributed to stronger El Niño activity, it suggests that the climate system is only about half as sensitive to increasing CO2 as previously believed”, Spencer said.
“Basically, previously it was believed that if we doubled the CO2 in the atmosphere, sea surface temperatures would warm about 2.5 C,” Spencer said. That’s 4.5° F. “But when we factor in the ENSO warming, we see only a 1.3 C (about 2.3° F) final total warming after the climate system has adjusted to having twice as much CO2.”
It was previously known that Pacific Ocean warming and cooling events come and go in roughly 30-year periods of predominance, where El Niño warming events are stronger than La Niño cooling events for approximately 30 years, followed by roughly three decades where the reverse is true.
During the period of this study, cooling events were dominant from the 1950s into the late 1970s. That was followed by a period of strong El Niño warming activity that lasted into the early 2000s. The current phase has seen increased La Niña cooling activity.
Spencer said it is reasonable to suspect that the increased La Niña cooling might be largely responsible for an ongoing “pause” in global warming that has lasted more than a decade. If that is the case, weak warming might be expected to revive when this phase of the El Niño-La Niña cycle shifts back to a warmer El Niño period.
The study was the result of a debate over whether clouds can be part of an active forcing mechanism for global warming, or are just a passive response to temperature change.
“What we found is, to explain the satellite data we had to invoke a change in clouds nine months before the peak of either an El Niño or a La Niña,” Spencer said. “When the clouds change, it takes time for that to translate into a temperature change.
“We get the best fit to the observations when we let clouds cause some of the temperature change. These cloud changes are occurring before the temperature starts to respond, so they can’t be caused by the temperature changes.”
Before an El Niño Pacific Ocean warming event, global cloud cover decreases, allowing more solar energy to reach the Earth’s surface and be converted into heat. On the flip side, before a La Niña Pacific Ocean cooling event, cloud cover increases, shading more of the Earth’s surface and reflecting an increased amount of solar energy back into space.
While changes in cloud cover intensify the warming or cooling of these ocean events,
Spencer and Braswell still found that two-thirds of the sea surface temperature changes during both El Niño and La Niña events are driven by changes in ocean mixing. But the one-third forcing by clouds turns out to be an important component, substantially changing our interpretation of how sensitive the climate system is to CO2 emissions.
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The role of ENSO in global ocean temperature changes during 1955–2011 simulated with a 1D climate model
Abstract
Global average ocean temperature variations to 2,000 m depth during 1955–2011 are simulated with a 40 layer 1D forcing-feedback-mixing model for three forcing cases. The first case uses standard anthropogenic and volcanic external radiative forcings. The second adds non-radiative internal forcing (ocean mixing changes initiated in the top 200 m) proportional to the Multivariate ENSO Index (MEI) to represent an internal mode of natural variability. The third case further adds ENSO-related radiative forcing proportional to MEI as a possible natural cloud forcing mechanism associated with atmospheric circulation changes. The model adjustable parameters are net radiative feedback, effective diffusivities, and internal radiative (e.g., cloud) and non-radiative (ocean mixing) forcing coefficients at adjustable time lags. Model output is compared to Levitus ocean temperature changes in 50 m layers during 1955–2011 to 700 m depth, and to lag regression coefficients between satellite radiative flux variations and sea surface temperature between 2000 and 2010. A net feedback parameter of 1.7Wm−2 K−1 with only anthropogenic and volcanic forcings increases to 2.8Wm−2 K−1 when all ENSO forcings (which are one-third radiative) are included, along with better agreement between model and observations. The results suggest ENSO can influence multi-decadal temperature trends, and that internal radiative forcing of the climate system affects the diagnosis of feedbacks. Also, the relatively small differences in model ocean warming associated with the three cases suggests that the observed levels of ocean warming since the 1950s is not a very strong constraint on our estimates of climate sensitivity.
What a stupid thing to say about a paper that caps CO2 sensitivity at ~25% of alarmist claims, and shows the path toward lowering that cap further.
My guess would be that it has something to do with what you’re smoking.
This post should be stickied up top. Far too important to be buried so quickly.
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Steven Mosher says:
November 11, 2013 at 12:44 pm
the biggest issue is that Roy hasnt estimated ECS, he has estimate TCR.
a 1.3C TCR translates into a 2.6C ECS.. thereabouts
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Mosh, the transient effects of any GHG are immediate (a couple days). The added “heat” can’t be stored in land OR water — LW from GHGs can’t get past the surface significantly. Obviously there is a TCR & ECS for SW forcings on earth’s climate (albedo, clouds), but only solar SW can penetrate the ocean & be “stored”.
Yes, I’ve read about “ocean diffusivity” in the basic calculations, but that smacks me of the myriad of other tuned, vaguely determined parameters, like aerosol or cloud effects.
milodonharlani says:
November 12, 2013 at 12:05 am
Smoking Frog says:
November 11, 2013 at 11:46 pm
That’s not what I’m saying at all.
It’s logarithmic all the way. The vast majority of warming occurs in the first 100 ppm. Each doubling after has progressively less effect, but is already so small as to be negligible.
If logarithmic “all the way”, then there is never a time when additional CO2 doesn’t have some effect, even as it gets extremely minor. Well, all the way until we have a pure 100% CO2 atmosphere.
I originally asked the question because I am under the impression that this concept discusses CO2 in a “pure state” with no other gasses also absorbing IR radiation. With the other gasses present in our atmosphere, there is only so much radiation left for CO2 and there is a point where it absorbs all it can: a “saturation” point. Are we close to that or am I under a misunderstanding?
beng says:
Mosh, the transient effects of any GHG are immediate (a couple days).
You don’t understand what you’re talking about.
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Roy Spencer,
Congratulations on the publication of the research.
For the benefit of those who wish to understand and work to correct gate keeping / bias in peer review, a synopsis of the story of the ‘no small task’ it took to publish your research is just as important as the research itself . . . maybe more important.
Please tell us what you can about the experience of getting the paper published. It might inspire others who might be discouraged.
John
So the bottom line here is that doubling of atmospheric CO2 will CAUSE a global temperature increase of 1.3 C (~ 2.34° F), i.e. CO2 will precede warmer temperature. Although I’m a big fan of Roy, I’m not a big fan of models proving much of anything in the real world. Models do what you tell them to do, so their results must be confirmed by real world data. When I look for cause-and-effect relationships in data over geologic time, I see a total lack of correlation of CO2 and temperature. That doesn’t mean CO2 has no effect at all, but it does mean that it is so small as to be insignificant relative to what is really driving climatic changes. All you have to do is look at temperature changes at almost any time scale, years, centuries, millennia and you will see that CO2 is not really a significant factor at all. I’ve published many such examples (just Bing or Google my name and you will find more than you want to know) so I won’t repeat them here. The point is that the magnitude of temperature changes in the geologic past is so many times greater than could possibly be caused by CO2 and the rates of temperature change are so rapid that trying to attribute much of anything to CO2 seems pointless. It’s much like attributing the behavior of an elephant to a flea riding on its back.
But what if you double CO2? The amount of CO2 in the atmosphere is so tiny (~0.039%) and its effect so small (~3.5%) it’s almost as good as doubling nothing—you still end up with nothing (the total change of CO2 in atmospheric composition is 0.009%). And trying to lever it by putting in a big water vapor factor doesn’t work because water vapor hasn’t increased since 1947 when CO2 emissions began to soar.
Try correlating any measureable change in temperature with CO2 just in the past century and you will see temperatures rising just as fast from 1915 to ~1945 without significant rise in CO2 as temperature rising from 1978 to 1998 when CO2 was increasing. And, of course, if you try relating CO2 rise from 1945 to 1977 with temperature, you get a negative correlation, i.e. temperatures went down while CO2 was rising. If you look at the sudden 1977 transition from cool to warming temperatures, it happened in a single year, not slowly with rising CO2. The same is true for more than 40 periods of warming and cooling since 1500 AD as seen in Greenland ice cores. So regardless of any theoretical warming effect of CO2, it is so small as to be totally overwhelmed by natural causes and therefore not really a relevant factor in climate change.
So what has Roy’s model told us about CO2 and global warming? Can the model results be confirmed by real time data? Does it have any impact on the cause of global climate change? As much as I admire Roy and his work, I’m afraid that the geologic record of many, many temperature changes far greater than anything possibly caused by CO2 conclusively shows that CO2 is not a relevant factor in climate change.
@ur momisugly Don Easterbrook
From Dr. Spencer: “…we see only a 1.3 C (about 2.3° F) final total warming after the climate system has adjusted to having twice as much CO2.”
Does this mean that 1.3 C is directly attributed to CO2 or that that is the maximum left over that could be attributed to CO2 and as we add other factors it will progressively decrease?
If “could be”, then he is moving the goal post closer to your “CO2 is not a relevant factor in climate change” comment.
Just wondering out loud.
Don Easterbrook You are exactly right . The problem is that the academic community and IPCC and the politicians are locked into thinking about climate from the viewpoint or output of models – built with the assumption that we know the physical mechanisms controlling climate and that CO2 is the main driver. Unfortunately most of the posts on this thread even from those who are anti the AGW paradigm are still approaching the climate question from the same physical mechanism mindset – they simply think that they can build a better model with lower CO2 sensitivity..The modeling approach is not only wrong because the models are structured incorrectly but inherently useless because the initial conditions cannot be quantified precisely enough to produce useful believable outcomes
The discussion needs to move to other more empirical forecasting paradigms along the lines of yourself ,Scafetta or that of my cooling forecast at
http://climatesense-norpag.blogspot.com
,
Dr Norman Page says:
“The discussion needs to move to other more empirical forecasting paradigms along the lines of yourself ,Scafetta”
Scafetta’s forecast includes 40-50% CO2 forcing and is hypothetical not empirical.
I refer to Scafetta’s as empirical because he starts off with a power spectrum analysis of the data to see what quasi cycles are actually there. If he extended his analysis to include a millennial cycle the amount of forcing due to CO2 would more or less evaporate. He is a full time academic and like
Spencer and everyone else in academia he would have difficulty getting published if he carried his approach to its logical conclusion. The way science is structured and funded these days -in many fields ,not only in climate science ,it is difficult to do anything other than to make marginal changes to the current consensus paradigm. As I said in the link above.
“The entire vast UN and Government sponsored AGW behemoth with its endless labyrinthine conferences and gigantic schemes for UN global control over the World and National economies is a prime example of the disasters Eisenhower warned against in 1961 he said :
“In the same fashion, the free university, historically the fountainhead of free ideas and scientific discovery, has experienced a revolution in the conduct of research. Partly because of the huge costs involved, a government contract becomes virtually a substitute for intellectual curiosity. For every old blackboard there are now hundreds of new electronic computers.
The prospect of domination of the nation’s scholars by Federal employment, project allocations, and the power of money is ever present and is gravely to be regarded. Yet, in holding scientific research and discovery in respect, as we should, we must also be alert to the equal and opposite danger that public policy could itself become the captive of a scientific technological elite. “
JohnWho says:
November 12, 2013 at 6:25 am
The effect may already have become so minor as to be swamped by H2O in most environments, such as the moist tropics. The logarithmic effect becomes effectively negligible at some point, possibly already reached, except perhaps in very arid environments such as the poles. In any case, sinks sooner or later will absorb the one, two or three molecules per 10,000 in dry air added to the previous one, two or three by increased T or human activity.
However some scientists seem to think that extremely high levels of CO2 (~10%) do have an effect, as that’s one hypothesis for the end of Snowball Earth episodes. IMO, climate science needs more realistic experimentation & unbiased observation & fewer GIGO models.
Dr Norman Page says:
“If he extended his analysis to include a millennial cycle the amount of forcing due to CO2 would more or less evaporate.”
Well not really, unless you expect a millennial cycle to only poke it’s nose up in the last quarter of the last century. He had not been able to model all of the recent warming, justifying a large CO2 forcing component, which unfortunately puts a strong warm bias on the forecast.
Not so – the general warming trend from the LIA including much of the 20th century warming is due to the millennial cycle – see Figs 3 and 4 on the last post at
http://climatesense-norpag.blogspot.com
Dr Norman Page says:
“the general warming trend from the LIA including much of the 20th century warming is due to the millennial cycle”
That is illusory, there is no trend on CET from say 1730 to 1930: http://snag.gy/2q2kT.jpg
the bulk of the warming is from 1988 onwards. Fig 4 in your post needs to be thought about first, for example the warm spike at 3300-3200 BP is a very cold period in the temperate zone, and 4800-4400 BP was a very warm period in the temperate zone, so the warm peak on your Fig 3 has been derived from a Greenland proxy, which is inverse to the temperate zone. After all the only two time that the River Nile froze in the last two thousand years was in 829 and 1010 AD.
My post says
” A review of candidate proxy data reconstructions and the historical record of climate during the last 2000 years suggests that at this time the most useful reconstruction for identifying temperature trends in the latest important millennial cycle is that of Christiansen and Ljungqvist 2012 (Fig 5)
http://www.clim-past.net/8/765/2012/cp-8-765-2012.pdf ”
I believe this to be the case The Christiansen proxy set has a good arealspread of different types of NH proxy data ( Check the original, ) The Fig 4 is important to show the millennial timing of the latest 2 or 3 cycles – the most recent are the most likely to be currently relevant to the next 1000 years.
Ulric Lyons says:
November 12, 2013 at 11:34 am
At the risk of sounding like a Warmunisto who says all weather & climate events are consistent with CACA & expected, even if completely opposite to prior predictions or projections, IMO the Nile freezing in 829 & 1010, ie during the first phase of the Medieval Warm Period, fits. These dates & other observations in the region “indicate the Azores anti-cyclone extending regularly into central Europe even in winter, thereby drawing north-easterlies across Egypt” (Water, Environment and Society in Times of Climatic Change, 1998, edited by Issar & Brown).
If you look at Fig 3 you will see that the variability about the moving average is very considerable. note e.g the sharp cold snap in the early 9th century close to the date you refer to,
I use figs 3 and 4 for forecasting the general trends. The decadal forecasts are based on reversing the trends of the last century and the neutron count data as representing solar activity trends.
Substantial Annual anomalies may well occur at any time due to Enso events and volcanic eruptions.
Ulric Lyons
I clearly showed the long slow thaw in my article of the same name when I reconstructed CET from 1538 to its instrumental start in 1659.
http://judithcurry.com/2011/12/01/the-long-slow-thaw/
The 1730 start date is from outside the main period of the LIA and was an extraordinarily warm decade on a par with the 1990’s according to Phil Jones.
tonyb
Dr Norman Page:
That warm spike around 1000 AD in the Greenland ice core proxy is the inverse to what the temperate zone was doing. If you look carefully you will see we are roughly at a level with ~4600yrs ago, a period of similar warmth in the temperate zone, and also a period of rapid cultural expansion.
climatereason:
How about CET 1706 to 1987 then: http://snag.gy/UehSu.jpg
Ulric Lyons
I must point out that my iPad automatically changed your first name to “uptick!”. No wonder, as do I detect a slight upwards trend?
1706 was still within the remarkable warming period. Start it during the real lia which was 1690 decade and see where it goes
However I just made the comment on the spencer temperature trend thread that the current cet anomaly is exactly the same in 2013 at plus 0.3 c as the satellite record today, thereby showing a 0.3 c warming over the 240 years of the 1772 Hadley cet record.
Cet has lost virtually all the gain made during the 1980/90 period. It’s not exactly scary if you can look back far enough
Tonb
““Our modeling shows that natural climate cycles explain at least part of the ocean warming we’ve seen since the 1950s,” said Dr. Roy Spencer”
Forgive me if I’m skeptical when someone tells me that the results of a computer model conclusively demonstrate something they’ve been arguing for years.
Check the Christiansen paper Fig1 and Table 1 linked earlier. The data he uses has a good spread over much of the NH .The peak at 1000 is therefore well documented for the NH
As the planet has been cooling for around 10,000 years and this and several other Holocene’s have all had temperatures warmer than today it s amazing that we have got this far with the AGW nonsense. Remember a few things…there has never been a warming of the Troposphere, climate models are biased towards warming…..and CO2’s ability to create heat is logarithmic so it cannot overheat the planet.
Tonyb says:
“Start it during the real lia which was 1690 decade and see where it goes.”
Yes it warms rapidly, then stays flat for centuries. I don’t buy the idea of a long slow thaw through CET. I also don’t buy Mann’s CET reconstruction for the 1200’s either:
http://curryja.files.wordpress.com/2011/12/6.jpg
That has come from the wrong interpretation of Greenland and Baffin Island cores:
http://wattsupwiththat.com/2013/08/23/the-medieval-warm-period-in-the-arctic/#comment-1398577