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.
Glynn,
Those equations don’t take into account the limited spectral response of Co2.
“If you find that the walls do get warmer from “body IR radiation”…”
Maybe you should get your spouse to selectively remove/add clothing while checking T(spouse) with IR thermometer?
Pretty sure removal will raise T(sp)–as measured, of course, not necessarily as he/she experiences it–while the addition of clothing will lower T(sp), since the radiated IR will be greater in the former case–I have the impression that the surface of clothing is generally cooler than the temperature of the underlying skin, so by Boltzmann’s law it should radiate less…
Just sayin’. 😉
@ur momisugly Col Mosby
The Clean Air Act was passed by Parliament in 1956. Seems a long pause between that and the 1980 warming.
“Secondly, ENSO is cyclical and there are equal numbers of both El Nino phases and La Nina phases. ”
I don’t believe this is an accurate statement. There have been more La Nina events in the last ten years than El Nino, for example.
Hmmmn. Another model. Maybe it’s OK, but I’ll stick to my belief in the Weather Gods for now.
Is the 1.3C equilibrium or not? In Spencer’s blog he says that Case I (2.2C) is equilibrium so I assume Cases II and III are also. Mosher says it’s the TCR and not the ECS. Can anyone clarify?
Roy Spencer says:
The first case (CASE I) uses only the RCP radiative forcings (also used by the latest crop of IPCC climate models) to see if we get about the same climate sensitivity as those models get (under the VERY important assumption that those are the ONLY forcings causing warming since the 1950s)… In that case we get about 2.2 deg. C of equilibrium warming in response to a doubling of atmospheric CO2, somewhat below the average of the IPCC models.
Emphasis mine.
The balance of Roy’s description of Roy’s paper steps that down to 2.0C for CASEII, and 1.3C for CASEIII, all ECS, not TCR.
A 1.3 ECS translates into a 1.3 ECS … thereabouts.
Roy Spencer versus Mark Hertsgaard on CNN Tonight discussing Haiyan..talk about casting your pearls before swine.
Looking at historic PDO cycles, the correlation between Global Warming cycles/Warm PDO cycles and Global Cooling/Cool PDO cycles is quite robust.
The two major 20th century warming cycles 1910~1945 and 1978~1998 took place during Warm PDO phases, and the 1945~1977 global cooling phase corresponds precisely to a cool PDO cycle.
The current PDO entered its 30-yr cool cycle in July 2008 and from 2009, the UAH cooling trend is -0.37C/decade. Obviously this short time period is much too short for statistical significance, but the lack of warming for the the past 17 years shows that something is seriously wrong with CAGW assumptions, especially in light of 1/3rd of ALL CO2 emissions since 1750 emitted over the past 17 years with NO tropospheric warming and FALLING temperature trends for HADCRUT4 since 2001. Nothing is adding up for the CAGW theory.
If you combine PDO phases and solar activity cycles, it becomes apparent that CO2’s contribution to total global warming is much less model assumptions. if the weak solar phase is also calculated into the mix, with a good chance for a Grand Solar Minimum cycle starting from 2020, there is an excellent chance global temperatures could very well fall for the next 70 years.
I think Lindzen’s calculation of CO2 climate sensitivity being around 0.6~0.7C is going to be the most accurate projection, which begs the question, why is CAGW still being taken seriously?
Why indeed…..
And so it goes…..until liberty and reason are restored…..
hswiseman says:
November 11, 2013 at 8:21 pm
Roy Spencer versus Mark Hertsgaard on CNN Tonight discussing Haiyan..talk about casting your pearls before swine.
Here it is. (3 minutes) I found it a bit frustrating to watch.
http://www.cnn.com/video/data/2.0/video/bestoftv/2013/11/12/exp-pmt-roy-spencer-mark-hertsgaard-climate-debate.cnn.html
Hertsgaard is an utter shyster.
If Dr. Spencer thought the paper would function as some type of olive branch to the AGW crowd, his interaction tonight on CNN with the skank-pie Mark Hertzgaard from The Nation should rapidly disabuse him of the notion. Hertzgaard considered the mere presence of Dr. Spencer on television as “journalistic malpractice”. A knock on the door in the middle of the night followed by a beating and a long car ride is only a matter of time if Hertzgaard had his druthers.
In the brave new world of thought control, speaking the truth is journalistic malpractice. Accepting the 97% lie at face value was a mistake, IMO, except perhaps Dr. Spencer feels that the questions asked in the bogus survey to gin up fake consensus were so uncontroversial that he had to go along with the results, however obviously disingenuously polemical.
After going through all this, I am swayed that Joe Bastardi, Chad Wozniak, and thisisnotgoodtogo
are correct.
milodonharlani says:
November 11, 2013 at 11:08 am
For purposes of CACA debate, “climate sensitivity”, whatever its value may be, applies only to the doubling from 280 to 560 ppm. As so often noted here, the response in global temperature to CO2 concentration is logarithmic, so that most of the warming occurs in the first 100 ppm or less. As MIT climate scientist Dr. Lindzen says, adding more molecules is like painting a wall white, which doesn’t get much whiter with each new coat. Most of the effect occurs in the first one or two coats. So the next doubling to 1120 ppm would have negligible effect.
That’s incoherent. If the response is logarithmic, it should be the same for each doubling, but you seem to be saying that the response is only logarithmic up to the doubling 280->560, after which it is negligible.
Like the IPCC models I’d be happier with these claims, if the simulation had started at the beginning i.e 1910.By omitting the period to 1940, the simulation avoided explaining the o.5C rise 1910-1940. This was a permanent rise which had to be accounted for for the rest of the century and took 30 years to resurface through the transport delay of the oceans and caused the 1970-1997 rise.
Joseph Bastardi says:
November 11, 2013 at 9:49 am
It isn’t Joe. Roy has been leaning further and further to the AGW side of the argument over recent years. I wonder why ?
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.
Alexander Biggs, on Dr. Spencer’s own blog, he stated this:
milodonharlani says:
November 12, 2013 at 12:05 am
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.
“It’s logarithmic all the way” contradicts “Each doubling has progressively less effect.”
Roy Spencer:
Congratulations on your achievement at getting this paper published in the Asia-Pacific Journal of Atmospheric Science. That achievement is another indication of the slow fading away of the AGW-scare.
The publication of your paper is an important step forward (in terms of ‘back to the future’) in the process of returning climate science to study of climate behaviour and away from the assumption that atmospheric CO2 is the “control knob” of climate behaviour.
I write to support the post of anthonyvioli (at November 11, 2013 at 12:25 pm) who thanks and congratulates you for your explanatory post at November 11, 2013 at 11:47 am. It makes the point I would have made were it not that you posted it yourself saying
Indeed so. As you say, the important points are
1.
Your attribution of “ENSO as a pseudo-forcing” reduces the possible attribution of atmospheric GHG forcing by about half to a new value of about 1.3°C from a doubling of atmospheric CO2 equivalent.
2.
And if other effects (e.g. AMO, indirect solar) can also be attributed then it is reasonable to suppose that there is probably additional reduction to the possible attribution of atmospheric GHG forcing.
Assuming those other effects provide a further halving of equilibrium climate sensitivity (ECS) then the result would be an ECS of less than 1.0°C from a doubling of atmospheric CO2 equivalent. This would agree with empirical – n.b. not model-derived – determinations which indicate climate sensitivity is less than 1.0°C for a doubling of atmospheric CO2 equivalent. This is indicated by the studies of
Idso from surface measurements
http://www.warwickhughes.com/papers/Idso_CR_1998.pdf
and Lindzen & Choi from ERBE satellite data
http://www.drroyspencer.com/Lindzen-and-Choi-GRL-2009.pdf
and Gregory from balloon radiosonde data
http://www.friendsofscience.org/assets/documents/OLR&NGF_June2011.pdf
And, importantly, if climate sensitivity is less than 1.0°C for a doubling of CO2 equivalent, it is physically impossible for the man-made global warming to be large enough to be detected because natural climate variability (e.g. from ocean thermal transport) is much larger. When something exists but is too small to be detected then it only has an abstract existence; it does not have a discernible existence that has effects (observation of the effects would be its detection).
Richard
Interesting that the CO2 lag after SST change is also nine months. Twice is coincidence, three times is a trend/enemy action.
It is correct:
Rising moist air may initiate a tornado or a tropical storm, if the surrounding is “ready” (high moisture in the surrounding air )for it.
See Alamaro:
http://web.mit.edu/alamaro/www/WMA_April_2006.pdf
Alamaro, M., Michele, J., Pudov, V.: “A Preliminary Assessment of Inducing Anthropogenic Tropical Cyclones Using Compressible Free Jets and the Potential for Hurricane Mitigation,” Journal of Weather Modification, Vol. 38, P. 82-96, 2006.
Wilson, I.R.G., 2013, Are Global Mean Temperatures
Significantly Affected by Long-Term Lunar Atmospheric
Tides? Energy & Environment, Vol 24,
No. 3 & 4, pp. 497 – 508
http://multi-science.metapress.com/content/03n7mtr482x0r288/?p=e4bc1fd3b6e14fd8ab83a6df24c8a72d&pi=11
Wilson and Sidorenkov find that there are four extended pressure features in the summer MSLP anomaly maps that are centred between 30 and 50 degrees S and separated from each other by approximately 90 degrees in longitude. In addition, they show that, over the period from 1947 to 1994, these patterns drift westward in longitude at rates that produce circumnavigation times that match the 18.6 year lunar Draconic cycle. These type of pressure anomaly pattern naturally produce large extended regions of abnormal atmospheric pressure that pass over the semi-permanent South Pacific sub-tropical high roughly once every ~ 4.5 years. These moving regions of higher/lower than normal atmospheric pressure increase/decrease the MSLP of the semi-permanent high pressure system, temporarily increasing/reducing the strength of the East-Pacific trade winds. This leads to conditions that preferentially favor the onset of La Niña /El Niño events that last for approximately 30 years. Wilson and Sidorenkov find that the pressure of the moving anomaly pattern changes in such a way as to favor La Niña over El Niño events between 1947 and 1970 and favor El Niño over La Niña events between 1971 and 1994. This is in agreement with the observed evolution of the El Niño/ La Niña events during the latter part of the 20th century. They speculate that the transition of the pattern from a positive to a negative pressure anomaly follows a 31/62/93/186 year lunar tidal cycle that results from the long-term interaction between the Perigee-Syzygy and Draconic lunar tidal cycles.
Roy Spencer says:
“Gee, if only ENSO can do that, what about the AMO, or indirect solar effects, or ???”
What about the direct solar effects that drive ENSO?
http://snag.gy/nf9SK.jpg