January 14th, 2020 by Roy W. Spencer, Ph. D.
In 2017, Christy & McNider published a study where they estimated and removed the volcanic effects from our UAH lower tropospheric (LT) temperature record, finding that 38% of the post-1979 warming trend was due to volcanic cooling early in the record.
Yesterday in my blog post I showed results from a 1D 2-layer forcing-feedback ocean model of global-average SSTs and deep-ocean temperature variations up through 2019. The model is forced with (1) the RCP6 radiative forcings scenario (mostly increasing anthropogenic greenhouse gases and aerosols and volcanoes) and (2) the observed history of El Nino and La Nina activity as expressed in the Multivariate ENSO Index (MEI) dataset. The model was optimized with adjustable parameters, with two of the requirements being model agreement with the HadSST global temperature trend during 1979-2019, and with deep-ocean (0-2000m) warming since 1990.
Since the period since 1979 is of such interest, I re-ran the model with the RCP6 volcanic aerosol forcing estimates removed. The results are shown in Fig. 1.
Fig. 1. 1D model simulation of global (60N-60S) average sea surface temperature departures from assumed energy equilibrium (in 1765), with and without the RCP6 volcanic radiative forcings included.
The results show that 41% of the ocean warming in the model was simply due to the two major volcanoes early in the record. This is in good agreement with the 38% estimate from the Christy & McNider study.
It is interesting to see the “true” warming effects of the 1982-83 and 1991-1993 El Nino episodes, which were masked by the eruptions. The peak model temperatures in those events were only 0.1 C below the record-setting 1997-98 El Nino, and 0.2 C below the 2015-16 El Nino.
This is not a new issue, of course, as Christy & McNider also published a similar analysis in Nature in 1994.
These volcanic effects on the post-1979 warming trend should always be kept in mind when discussing the post-1979 temperature trends.
NOTE: In a previous version of this post I suggested that the Christy & McNider (1994) paper had been scrubbed from Google. It turns out that Google could not find it if the authors’ middle initials were included (but DuckDuckGo had no problem finding it).
Google is becoming more and more partisan with its AI-tuned to produce a biased search engine.
I use DuckDuckGo or Bing for anything related to climate or political.
Google is just a band of partisan hacks who wants the world to turn to socialism.
On a volcanic cooling note, another Philippine volcano, Mt Taal, appears to be getting ready to blow its load like Mt Penatubo did in June 1991.
Water… meet molten caldera. Water happens next?
https://www.newsweek.com/future-taal-volcano-eruptions-could-cause-tsunamis-dangerous-lava-mixture-flows-experts-warn-1482095
Solar minimums are so much fun for volcano watchers.
So, 40% of the warming was due to the major greenhouse gas, water vapor, condensing due to the colder atmosphere, thus resulting in the coolant, sulfur dioxide being washed out.
Now all that needs to be demonstrated is that, CO2, that rises, when it is warm, into the upper atmosphere and transports water vapor with it, mechanically helps the process of the water vapor to condense after radiating heat into space, and thereafter falling back to the ground, cooling it, as snow or rain.
CO2 is a mechanistic coolant. Also notable in the ice record where the temperature drops AFTER the CO2 rises.
This data analysis should convince reasonable people [though fewer of this animal is around today] that the increase in warming is a natural phenomenon and NOT man-caused. For the moment, dollars and ideology continue to blind people to truth.
It is interesting to see the “true” warming effects of the 1982-83 and 1991-1993 El Nino episodes, which were masked by the eruptions.
Pinatubo volcanic cooling was vastly overtaken by falling solar output.
Your volcanic forced warming trend is spurious.
So sea temperatures are driven by SW, visible light, which we know increased due to sun spots to about 1980, but because of volcanic activity not all this increase in SW was let through the atmosphere, delaying the temperature increase.
Makes sense, and why warming has gone on past the sunspot peak, and defeats this used as an argument against solar warming.
I remember Suzuki going on about the massive release of CO2 when Pinatubo blew its top, and how the world was going to come to an end etc as a result. And all that happened was that we had a .5 degree drop in temp for about two years and pretty sunsets.
I wrote to him several times asking him why he still sees fit to lecture us about CO2 and climate change when his ideas were proven so utterly wrong at that time by fact. I did not receive an answer.
Does anyone have a link to Suzuki’s insane blathering’s at the time? I looked a while back and couldn’t find anything, funny that, you couldn’t get away from it at the time. I’ll try again, its worth a look, total panic and dire predictions…the full hysterical emotional blowout….highly amusing.
Posts from 2016 and 2017:
https://wattsupwiththat.com/2017/10/25/study-ice-sheets-may-melt-rapidly-in-response-to-soot-from-distant-volcanoes/comment-page-1/#comment-2645637
Let’s do a full-Earth-scale test to eliminate scale-up uncertainties:
Century-scale volcanoes like El Chichon in 1982 and Pinatubo in 1991 caused global cooling of about 0.5C, which then dissipated over several years. That global cooling was the NET EFFECT of ALL factors, including the reduced transparency of the atmospheric due to airborne volcanic aerosols and particulates (the dominant factor) and lesser impacts such as ash darkening of ice sheets that caused some melting.
In summary, the NET EFFECT of large-scale volcanoes is temporary global cooling – there is no evidence of any runaway warming effects from volcanoes.
Regards, Allan
https://wattsupwiththat.com/2017/09/20/from-the-the-stupid-it-burns-department-science-denial-not-limited-to-political-right/comment-page-1/#comment-2616345
NOT A WHOLE LOTTA GLOBAL WARMING GOIN’ ON!
Unlike the deeply flawed computer climate models cited by the IPCC, Bill Illis has created a temperature model that actually works in the short-term (multi-decades). It shows global temperatures correlate primarily with NIno3.4 area temperatures – an area of the Pacific Ocean that is about 1% of global surface area. There are only four input parameters, with Nino3.4 being the most influential. CO2 has almost no influence. So what drives the Nino3.4 temperatures? Short term, the ENSO. Longer term, probably the integral of solar activity – see Dan Pangburn’s work.
Bill’s post is here.
https://wattsupwiththat.com/2016/09/23/lewandowsky-and-cook-deniers-cannot-provide-a-coherent-alternate-worldview/comment-page-1/#comment-2306066
Bill’s equation is:
Tropics Troposphere Temp = 0.288 * Nino 3.4 Index (of 3 months previous) + 0.499 * AMO Index + -3.22 * Aerosol Optical Depth volcano Index + 0.07 Constant + 0.4395*Ln(CO2) – 2.59 CO2 constant
Bill’s graph is here – since 1958, not a whole lotta global warming goin’ on!
My simpler equation using only the Nino3.4 Index Anomaly is:
UAHLTcalc Global (Anom. in degC, ~four months later) = 0.20*Nino3.4IndexAnom + 0.15
Data: Nino3.4IndexAnom is at: http://www.cpc.ncep.noaa.gov/data/indices/sstoi.indices
It shows that much or all of the apparent warming since ~1982 is a natural recovery from the cooling impact of two major volcanoes – El Chichon and Pinatubo.
Here is the plot of my equation:
https://www.facebook.com/photo.php?fbid=1106756229401938&set=a.1012901982120697.1073741826.100002027142240&type=3&theater
I added the Sato Global Mean Optical Depth Index (h/t Bill Illis) to compensate for the cooling impact of major volcanoes, so the equation changes to:
UAHLTcalc Global (Anom. in degC) = 0.20*Nino3.4IndexAnom (four months earlier) + 0.15 – 8*SatoGlobalMeanOpticalDepthIndex
The “Sato Index” is factored by about -8 and here is the result – the Orange calculated global temperature line follows the Red actual UAH global LT temperature line reasonably well, with one brief deviation at the time of the Pinatubo eruption.
Here is the plot of my new equation, with the “Sato” index:
https://www.facebook.com/photo.php?fbid=1443923555685202&set=a.1012901982120697.1073741826.100002027142240&type=3&theater
I agree with Bill’s conclusion that
THE IMPACT OF INCREASING ATMOSPHERIC CO2 ON GLOBAL TEMPERATURE IS SO CLOSE TO ZERO AS TO BE MATERIALLY INSIGNIFICANT.
Regards, Allan
It is always amazing for me to look at head posts or comments telling us that if the volcanoes hadn’t erupted at the beginning of the satellite era, the past would be warmer and thus the trend lower.
As if the trend was in their life the only thing that would matter ever.
The trend would have been lower as well if the two big El Ninos wouldn’t have happened, and of course higher without the La Ninas these people always ‘forget’:
Thus
– either you keep the UAH temperature series as it is,
– or you remove volcano and ENSO signals.
Exactly that was done by Grant Foster and Stefan Rahmstorf for surface series in 2011, and by Benjamin Santer, Celine Bonfils & al for the lower troposphere in 2014.
The latter group used RSS rev. 3.3 which has been nearly identical to UAH6.0.
Their result: the residual trend after removal was about 0.09 C / decade (vs. 0.12 C for the original data at that time). This means that volcanoes and Ninos and Ninas account for about 30 % alltogether.
Exactly that you would obtain with UAH6.0 LT.
Rgds
J.-P. D.
All the really big volcanic eruptions in the recent past have occurred during solar minimums. A lot of theories why but no one has really come up with one that sticks. https://pubs.giss.nasa.gov/abs/st07500u.html
Yes I wish I had saved every valuable paper I have come across because Google is certainly making them hard to find, perhaps impossible unless you remember the authors first middle and last name because apparently remembering most of the title doesn’t work.
By their nature, volcanic eruptions are not predictable, long term. To create scenarios of the impact of volcanic aerosols, one can rely on statistical averages of the past. However, there is no guarantee that ‘the recent past is the key to the near future.’ It has often been remarked that civilization, as we know it, would have been impossible during periods of much greater volcanic activity in the distant past. Mann famously hypothesized a significant volcanic event (circa 2014) that lowered his 1988 temperature predictions for his “Draconian Reductions” scenario — an event that did not take place!
Volcanic eruptions that have global impacts can and do take place at unpredictable times and places, lowering global temperatures for a couple of years. That results in most scenario-driven, average global temperature predictions being an upper-bound, because there are no natural (or man-made) discrete phenomena of similar frequency or magnitude that cause warming. One might argue that the quasi-periodic El Nino/La Nina events have a comparable impact. However, they have opposing effects and are somewhat predictable. In that sense, volcanic eruptions are uniquely asymmetric in their impacts, leading to unpredictable, punctuated cooling.
I am curious about how the weather data gets manipulated to show temperature changes over time.
Are researchers using the daytime high and low or are they taking an hourly average over the day. In North American the daily high is often a short term spike and not indicative of the days heat.
So,when we hear that we are having the highest temperature months and years on record…what exactly is their point of measurement? Are the recording stations in cities and airports and are they accurately reading the true temperature or an asphalt influenced false high?
Has anyone been able to get funding money to really study this.
From the article: “The peak model temperatures in those events were only 0.1 C below the record-setting 1997-98 El Nino, and 0.2 C below the 2015-16 El Nino.”
An upper boundary on warming here? Temperatures reach these high levels, which are within one-tenth of a degree C of each other, and then the temperatures fall off for decades.
Lower boundary, the cool of the 1910’s and 1970’s?
Here a U.S surface temperature chart to illustrate the possible boundaries of our current temperature record.
Like Trump says (paraphrasing): The temperatures go up, and then they go down, and then they go up again.
They do this within certain bounds it seems. Trump didn’t say that part. 🙂
“It is interesting to see the “true” warming effects of the 1982-83 and 1991-1993 El Nino episodes, which were masked by the eruptions.”
There would not have been El Nino episodes in 1982-83 and 1991-92 without the eruptions, they were a response to the volcanic aerosol cooling. The solar wind speed was increasing in 1982 and 1991, the wrong direction for El Nino conditions.
As I have indicated in a reply before, we know that Milankovic cycles account for mid-term climate variability and Shaviv’s galactic orbit may account for long term climate variability. Short term cycles certainly exist but I’ve seen no convincing explanation as to why. Natural scientific curiosity leads me to wonder about whether the lunar orbit has an effect on climate. The reason may not be obvious, but the moon’s orbit determines the tides. In my part of the world, the tide varies by 6 feet over a 12 hour cycle. It’s hard to believe that if the tide is variable, that it has no impact on climate. Like the Earth’s orbit around the Sun, the Moon’s orbit is not perfect. Therefore, there is tidal variation. High tide and low tide vary. Wouldn’t it be interesting if climate variation came down to three astronomical factors, the Sun’s orbit around the galaxy, the Earth’s orbit around the Sun, and the Moon’s orbit around the Earth. .