Small volcanic eruptions could be slowing global warming
From the AGU: WASHINGTON, DC— Small volcanic eruptions might eject more of an atmosphere-cooling gas into Earth’s upper atmosphere than previously thought, potentially contributing to the recent slowdown in global warming, according to a new study.
Scientists have long known that volcanoes can cool the atmosphere, mainly by means of sulfur dioxide gas that eruptions expel. Droplets of sulfuric acid that form when the gas combines with oxygen in the upper atmosphere can remain for many months, reflecting sunlight away from Earth and lowering temperatures. However, previous research had suggested that relatively minor eruptions—those in the lower half of a scale used to rate volcano “explosivity”—do not contribute much to this cooling phenomenon.
Now, new ground-, air- and satellite measurements show that small volcanic eruptions that occurred between 2000 and 2013 have deflected almost double the amount of solar radiation previously estimated. By knocking incoming solar energy back out into space, sulfuric acid particles from these recent eruptions could be responsible for decreasing global temperatures by 0.05 to 0.12 degrees Celsius (0.09 to 0.22 degrees Fahrenheit) since 2000, according to the new study accepted to Geophysical Research Letters, a journal of the American Geophysical Union.
These new data could help to explain why increases in global temperatures have slowed over the past 15 years, a period dubbed the ‘global warming hiatus,’ according to the study’s authors.
The warmest year on record is 1998. After that, the steep climb in global temperatures observed over the 20th century appeared to level off. Scientists previously suggested that weak solar activity or heat uptake by the oceans could be responsible for this lull in temperature increases, but only recently have they thought minor volcanic eruptions might be a factor.
Climate projections typically don’t include the effect of volcanic eruptions, as these events are nearly impossible to predict, according to Alan Robock, a climatologist at Rutgers University in New Brunswick, N.J., who was not involved in the study. Only large eruptions on the scale of the cataclysmic 1991 Mount Pinatubo eruption in the Philippines, which ejected an estimated 20 million metric tons (44 billion pounds) of sulfur, were thought to impact global climate. But according to David Ridley, an atmospheric scientist at the Massachusetts Institute of Technology in Cambridge and lead author of the new study, classic climate models weren’t adding up.
“The prediction of global temperature from the [latest] models indicated continuing strong warming post-2000, when in reality the rate of warming has slowed,” said Ridley. That meant to him that a piece of the puzzle was missing, and he found it at the intersection of two atmospheric layers, the stratosphere and the troposphere– the lowest layer of the atmosphere, where all weather takes place. Those layers meet between 10 and 15 kilometers (six to nine miles) above the Earth.
Traditionally, scientists have used satellites to measure sulfuric acid droplets and other fine, suspended particles, or aerosols, that erupting volcanoes spew into the stratosphere. But ordinary water-vapor clouds in the troposphere can foil data collection below 15 km, Ridley said. “The satellite data does a great job of monitoring the particles above 15 km, which is fine in the tropics. However, towards the poles we are missing more and more of the particles residing in the lower stratosphere that can reach down to 10 km.”
To get around this, the new study combined observations from ground-, air- and space-based instruments to better observe aerosols in the lower portion of the stratosphere.
Four lidar systems measured laser light bouncing off aerosols to estimate the particles’ stratospheric concentrations, while a balloon-borne particle counter and satellite datasets provided cross-checks on the lidar measurements. A global network of ground-based sun-photometers, called AERONET, also detected aerosols by measuring the intensity of sunlight reaching the instruments. Together, these observing systems provided a more complete picture of the total amount of aerosols in the stratosphere, according to the study authors.
Including these new observations in a simple climate model, the researchers found that volcanic eruptions reduced the incoming solar power by -0.19 ± 0.09 watts of sunlight per square meter of the Earth’s surface during the ‘global warming hiatus’, enough to lower global surface temperatures by 0.05 to 0.12 degrees Celsius (0.09 to 0.22 degrees Fahrenheit). By contrast, other studies have shown that the 1991 Mount Pinatubo eruption warded off about three to five watts per square meter at its peak, but tapered off to background levels in the years following the eruption. The shading from Pinatubo corresponded to a global temperature drop of 0.5 degrees Celsius (0.9 degrees Fahrenheit).
Robock said the new research provides evidence that there may be more aerosols in the atmosphere than previously thought. “This is part of the story about what has been driving climate change for the past 15 years,” he said. “It’s the best analysis we’ve had of the effects of a lot of small volcanic eruptions on climate.”
Ridley said he hopes the new data will make their way into climate models and help explain some of the inconsistencies that climate scientists have noted between the models and what is being observed.
Robock cautioned, however, that the ground-based AERONET instruments that the researchers used were developed to measure aerosols in the troposphere, not the stratosphere. To build the best climate models, he said, a more robust monitoring system for stratospheric aerosols will need to be developed.
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The paper:
Total volcanic stratospheric aerosol optical depths and implications for global climate change
Abstract
Understanding the cooling effect of recent volcanoes is of particular interest in the context of the post-2000 slowing of the rate of global warming. Satellite observations of aerosol optical depth (AOD) above 15 km have demonstrated that small-magnitude volcanic eruptions substantially perturb incoming solar radiation. Here we use lidar, AERONET and balloon-borne observations to provide evidence that currently available satellite databases neglect substantial amounts of volcanic aerosol between the tropopause and 15 km at mid to high latitudes, and therefore underestimate total radiative forcing resulting from the recent eruptions. Incorporating these estimates into a simple climate model, we determine the global volcanic aerosol forcing since 2000 to be −0.19 ± 0.09 Wm−2. This translates into an estimated global cooling of 0.05 to 0.12 °C. We conclude that recent volcanic events are responsible for more post-2000 cooling than is implied by satellite databases that neglect volcanic aerosol effects below 15 km.
http://onlinelibrary.wiley.com/doi/10.1002/2014GL061541/abstract?campaign=wlytk-41855.5282060185
Volcanoes are not the only source of sulphuric acid aerosols look here http://www.waterencyclopedia.com/A-Bi/Algal-Blooms-in-the-Ocean.html and scroll down to Coccolithophores. Major photosynthetic algal foodstuff – largest component of chalk, responds to increasing temperature and increasing CO2 levels, major contributor to carbon sink. During their experiments did they check on other sources of Sulphuric acid. Were there any significant algal blooms at the time for instance
The cause of the pause lies mainly in the squalls.
I hear the CO2 crew have a new book out for Christmas, its called ‘101 ways to flog a dead horse’.
“… intersection of two atmospheric layers, the stratosphere and the troposphere”
Isn’t that called the tropopause?
Obama’s first edict should mandate we stop causing volcanic activity because it is sending the wrong message about the impending climate catastrophe to be covered in a later edict. Since there is strong correlation between fracking, volcanic activity, and the pause (reality is suspended here for the good of the people per Gruber’s first postulate) the first regulation in the first edict will be to halt all fracking. This has the side benefit of distracting everyone’s attention from the Gruber fallout which will serve to keep Obamacare on track.
Since this first edict is also well aligned with the more important goal of destroying the US economy it should sale right through the house and senate. And if it doesn’t, BO has his pen at hand.
I suggest we take all that IPCC-triggered printed crap about CAGW, make a nice pulp out of it with the help of some heat-hiding seawater and fill these reckless killer-volcanoes up to the brim. But afaik volcanoes are more intelligent and certainly longer in existence than mankind, they will soon realize what muck is served and might spit it out again…
200 million tons a year from volcanoes =
2,000,000,000,000 tons in the last ten thousand years
550,000,000,000 from fossil fuels/land use since 1870
http://www.wri.org/blog/2013/11/carbon-dioxide-emissions-fossil-fuels-and-cement-reach-highest-point-human-history
“2,000,000,000,000 tons in the last ten thousand years
550,000,000,000 from fossil fuels/land use since 1870”
and the chances of that claim having any degree of accuracy worth a dam is what ?
There is a very big difference between a guess, not matter how intelligent, and a value which is know through good measurement. With proxies you have the former no matter how much people like to pretend you have the latter, hence the need for error margins which are often themselves another guess.
Shouldn’t fossil fuels and land use be separated and contributions quantified anyway?
“Small volcanic eruptions might …” Oops! Well, that saved me some time. I’ll go check out the polar bear article.
Looks like Beng has nailed it. More plausible than at least 50 of the other other potential causes. Somebody please add squalls to the official list.
Reblogged this on Public Secrets and commented:
Now that the “warmth is hiding in the deep ocean” explanation has been debunked, climate alarmists are grasping at other straws to something to explain the lack of global warming for the past almost-20 years. Anything other than “a natural cycle.” I’m not saying this reason is impossible, but I wouldn’t bet on it.
Let’s see now, what does the actual data say:
is going to be so miserably low as to make you slink from the room with your tail between your legs, even allowing for one or two “discernible” volcanic events in that range, most notably a double-whammy in 2010.
http://www.phy.duke.edu/~rgb/mlo-tran.jpg
Hmmm, I’d say it says “claim refuted”. The actual measurement of top of the troposphere total insolation is almost completely flat across the entire range from 1959 to the present except for clearly visible major volcanic eruptions and a smattering of stuff in the 60’s that is arguably related to nuclear testing. I made this graphic myself with R and the published Mauna Loa data from here:
http://www.esrl.noaa.gov/gmd/grad/mloapt.html
so it is readily checkable. The thick, straight, black line is at 0.93 and is there just to let the eye see just how little top of troposphere insolation has varied over the last 65 years. It is absolutely true that there are a number of highly puzzling features in this figure. Since 2000, the ML data has an annual beat that appears to be almost perfectly regular. This isn’t unusual, but the fact that the data before then is much noisier and with a much less discernible and sharp seasonal fluctuation is extremely odd. Volcanic eruptions are extremely visible as an interruption in top of troposphere insolation relative to the nearly constant baseline — a sudden, sharp drop and smooth non-exponential recovery over 2 to 5 years.
http://www.woodfortrees.org/plot/hadcrut4gl/from:1970/to:2000/plot/hadcrut4gl/from:1970/to:2000/trend
Note well: Over the period of the most rapid warming visible in the entire 20th century from 1985 to 1998, Pinatubo happened, followed by the 1998 super-ENSO with its nearly opposite effect. El Chichon happened in 1982, ejected massive amounts of Sulphur Dioxide into the atmosphere (7 million metric tons!) and had no visible effect on global climate in the 1980s! Mount St. Helens doesn’t even show up on the Mauna Loa data — it simply wasn’t big enough to register! Only Pinatubo appears to have had an effect, and its supposed effect is of the exact order of magnitude as the natural variation of the system so that one cannot even be certain that it actually cooled the climate. If it did, why didn’t El Chichon?
I would say that this simple graph categorically refutes the hypothesis that occult vulcanism is somehow responsible for “the pause”. The causal chain is “lots of small or undersea volcanoes are emitting enough “stuff” that they are affecting insolation and hence causing cooling”. Mauna Loa data shows no statistically significant change in top of troposphere broadband insolation where it is is demonstrably sensitive to volcanic aerosols and indeed, the reduction in insolation in the mid-60’s could indeed be due to a collection of six smaller eruptions in five years (although a similar stretch in the mid-70’s produced no such dip).
To conclude. The actual measured top of troposphere global insolation shows no variation of the sort hypothesized to be responsible for the apparent cessation of global warming post-2000 over precisely the times from 2000 to the present. It has been almost perfectly flat. It is rare to see a hypothesis that is actually even more unlikely than the current crop of hypotheses that connect warming and cooling to cosmic ray modulation of cloud formation and hence albedo, but this one beats it hands down as it proposes a hypothesis that actually contradicts the data. Second, the actual data shows that even actual variation of top of the troposphere insolation by amounts as large as 10% peak to over 1% sustained for as long as five years produces almost no visible modulation of the temperature trend of the time discernible from unpredictable natural variation. Imagined variation that is surely of order no greater than 0.1% is supposed to be cancelling out 0.2 to 0.5 C of warming that “should” have occurred during this interval (depending on whether you take your feedback amplification from the slightly or completely insane end of things)?
I don’t think so.
And you don’t even want to think about fitting a “linear trend” to the post 2000 top of troposphere insolation data. I can tell you right now that
This does not rule out aerosol modulation of lower troposphere cloud cover, but then one really does have to face up to the fact that GCR’s are a competing, and indeed possibly heterodyning, hypothesis and you still have to explain the lack of effect to volcanic eruptions that are a full order of magnitude or two more powerful back in the 1980’s when global warming was actually following the script that Hansen was attempting to write…
rgb
I’m ready for global warming pause excuse number XX, “It appears the climate just isn’t very sensitive
to CO2”.
That’s number zero.
The cause
Of the pause
Exposes all the flaws
I do think these researchers are making mountains out of mole hills, or should I say large volcanoes out of small ones.
I put this down as another one of the fifty-plus papers looking for the lost heat that causes hiatus. Since experimental observations are involved the first question is whether such observations exist for small volcanoes that are not conveniently located to be related to the hiatus? Just how many such small volcanoes are known and what data do we have on their emissions? In setting up the background they also use some questionable assumptions about volcanic cooling in general. What I object to also is this uninformed opinion: “The warmest year on record is 1998. After that, the steep climb in global temperature observed over the twentieth century appeared to level off.” 1998 was the warmest all right because it was a super El Nino. It is not to be connected with any other warming and happens only once a century. That “steep climb over the twentieth century does not exist, however. There was a standstill in warming from 1979 to 1997 that is hidden in all ground-based temperature curves by increasing the slope of the temperature curve in the eighties and nineties. I pointed that out in my book “What Warming?” in 2010 but nothing happened.They brazenly kept it up and extended this fake slope to the twenty-first century with the absurd result that now their 2010 El Nino peak is higher than the 1998 super El Nino was. As to the rest of twentieth century, it started out with an early century natural warming that came to an abrupt halt in 1940 when the World War II cold wave hit. There was a precipitous drop of temperature followed by a slow recovery that took 35 years. As a result, global temperature did not return to the 1940 level again until 1980, at which point a warming hiatus set in. It lasted until the super El Nino arrived which was a game changer. This was followed by a short step warming that raised global temperature by a third of a degree Celsius above the 1990 level in only three years and then stopped. It was followed by another hiatus – ours. The only temperature curve you can trust after 1979 is satellite temperatures from UAH and RSS. They differ slightly and I prefer UAH because I keep getting cooling from RSS. Now back to volcanic cooling. I hate to tell you that but it does not exist for any volcanoes in historic time. What are pointed out as volcanic cooling pockets are nothing more exotic than misidentified La Nina valleys. All temperature curves carry the stamp of the ENSO oscillation in the form of alternating El Nino peaks with La Nina valleys in between. This specifically applies to Pinatubo that they call “cataclysmic.” Its eruption coincided with an El Nino peak and the La Nina valley that followed was taken over as its volcanic cooling period and is so marked on temperature charts. But you can’t do that with El Chichon and they are all scratching their heads. The explanation is that its eruption coincided with a La Nina valley. Now answer this. If a cataclysmic eruption did not noticeably change the climate, why should we believe that small eruptions can do that?
[If you are commenting from Facebook-type editor, or from a cell phone/handset device that “sends” when the carriage return is entered, consider using “Shift + Enter” to establish internal paragraph markings in your replies. They are (usually) technically challenging and interesting, but are very, very difficult to read as-sent. .mod]
Paragraphs, please!
Arno, you make a number of assertions here, and I’m not unwilling to believe them, but not without a very direct and quantitative and reproducible basis outside of the assertions themselves. You are basically accusing Hadley, GISS, etc of overt fraud, and you are asserting that the correct global temperature/anomaly is completely different. One has the feeling that there is a temperature series out there, let’s call it ArnoT, that starts from the same set of publicly available data that all of these series have to start from and that gets it right.
For example, you assert that there was no warming in the 80s and 90’s up to the ENSO event, and that they are somehow successfully biasing even modern post 2000 temperatures so that they show a warming trend (except, of course, that they DON’T show a warming trend). I’m having a hard time reconciling all of these assertions with one another and things like HadCRUT4 or GISSTEMP. Groups like Berkeley that have put together their own global temperature estimate to compare to these two — are you asserting that they are all in cahoots? Because I think Steve Mosher would disagree — they from all reports tried to do their — cough cough — BEST, and if anything the person that spearheaded the project was and remains a lukewarmist.
I’m sympathetic, as I said, to your assertion that they make an error because there are things about the patterns of global weather that don’t match up well with the narrative of their temperatures, and because e.g. HadCRUT4 doesn’t correct for UHI at all and GISS corrects for it (from what I’ve read) backwards, so that it somehow increases the apparent warming on average instead of strictly decreasing it. I want to believe you. But I mistrust my own biases and beliefs. So:
Evidence, please.
In particular, what raw data are you basing your statement on? How do you process it? Where is your ArnoT dataset (and the code used to convert the raw data into ArnoT)? You have to solve the same problem that Hadley, GISS, Berkeley, etc have to solve — take a huge, disparate set of station measurements of temperature from over a century and a half and distill them into global temperatures and a global temperature anomaly. I’m skeptical that anybody can do this at the precision claimed simply because we lack adequate sampling of maybe 80% of the Earth’s surface for most of that time — most of the oceans, all of Antarctica, most of Australia, much of central Asia, much of the polar arctic, much of South America. Indeed, the only places we do sample pretty well are major urban civilized enclaves — Europe, the eastern part of North America, the coastal regions of South America and Australia, and selected parts of the colonial empires, e.g. India and parts of Africa, plus the shipping lanes connecting them (which are sampled irregularly and with terrible methodology, but are not completely unknown as is most of the ocean for most of that time).
Ignorance of global temperatures before 1900 I can easily believe, adequate knowledge of global temperatures from 1900 through 1950 I can totally believe, but in the post WWII world with jet aircraft and then satellites and with even forgotten parts of the Pacific and Antarctica suddenly possessing strategic value, from 1950 to 1970 our knowledge rapidly increased, and from the 1970s/1980s to the present, we really did start to get a decent picture of global temperature and other things. You’re saying that the major temperature anomalies of the 1980s and 1990’s in particular are a fraud?
Evidence, please. Ideally specific lines in the GISS source (which is published, by law) that make errors, or specific data processing steps that you disagree with in the equally published GISS data. Hadley may have a hard time providing the basis for their past estimates after Jones supposedly lost some of the data, but I’m pretty sure GISS,
BEST, and so on can and do provide all of theirs.
rgb
What? No small eruptions during the 80’s and 90’s? Pinatubo made a 2 year glitch but didn’t have as big a long term impact?
Quite the range .05 to .12, still not enough to counter the models.
Is spraying some sulfur dioxide in the upper atmousphere all it takes to counter global warming?
Problem solved.
Yup, that’s it. At worst.
We can all relax and enjoy the benefits of more CO2 in our air.
My pet plants are singing a happy tune.
Since when did slow become synonymous with stop. As in “the warming has slowed”.
So an alarmist supporter now concedes that there actually is a hiatus, and not that “the
heat” has magically “gone to the bottom of the oceans”. In this case all the talk about global changes being due to “warming” or “climate change” are therefore gibberish, as we already knew anyway.
One of the comments mentions spraying sulphur dioxide into the atmosphere therefore as a consequential solution to actual global warming. A great deal of chemical atmospheric spraying has already been recently done, for reasons seemingly not made clear, but one suggestion was to lessen GW. If there is any substance to this theory, it could be claimed that that is the reason for the “hiatus”, yet that claim has not arisen, to my knowledge. Any thoughts on this?
If there was any substance to the theory they would be proclaiming it. It’s probably got a darker purpose, otherwise – why is it so secretive?
Agreed. Up to no good, as usual. Especially as no knows who is organizing/implementing/funding/authorizing the process.Other priorities have limited my researching this chem-trail attack on us.
Mods: Chemtrails are paranoid poop.
Why would anyone use such an indiscriminating means of chemical mind-control.. even if it was real?
This embarrasses the whole site. And as a regular here, I object.
[We usually kill those references when we see them. If one got by, locate it -> mark for deletion. .mod]
Its amazing the greens have not tried to ban these,
http://petapixel.com/2014/07/21/self-taught-photographers-photographs-steam-locomotives-breathtaking/
beautiful pictures.
I understood volcanoes played a crucial part in the scheme of things, returning life-giving CO2 into the atmosphere, derived from the remains of age-old crustaceans on the sea bed, these having been conveyed underground by the movement of tectonic plates. And isn’t it this CO2, abruptly discharged by volcanoes erupting after millennia of being bottled-up during ice-ages, that causes enough global warming to bring the world out of an ice-age? Now we are invited to forget all that so as to make observations fit the AGW conjecture. Volcanoes making the world cooler? Yeah, right.
And so we come to the 60th excuse for the ‘Pause’.
What’s the grant–value if I can find the 61st?
http://hockeyschtick.blogspot.com.au/2014/07/updated-list-of-29-excuses-for-18-year.html
I just learned that there actually is no pause….2014 was the hottest ever in every respect! So sayeth NBC.
Quote:
“Even if it’s freezing in your personal universe, Earth as a whole just broke three “warmest” records and is likely to see 2014 go down as the warmest since record keeping began in 1880, scientists reported Thursday.”
So it is the “warmest ever” even if it is freezing. Funny enough, this year, everybody seems to have been freezing. In continental Europe it was necessary to switch on the heater several times this August – a first. But that was just in our personal European universe of course.
http://www.nbcnews.com/science/environment/2014-boils-toward-warmest-year-ever-three-more-records-broken-n252776
“BOILS toward warmest year ever!?” That’s what happens when I put the teakettle on the stove. Maybe the climate pundits should move their thermometers outside. And away from the dryer vent, please.
Oh, wait. I get it. It’s cold here in MY personal universe, but in whatever alternate universe these aliens come from things are really heating up…
Incidentally, whenever I check the local weather report online I look at the historic high for this area (Mendocino County, California). About 90% of the time it is in the first half of the 20th century and most often in the first three decades. Today’s record is 80 deg F in 1932. The high for today is 50 with much needed rain.
Pater,
You might want to read this:
http://www.drroyspencer.com/2014/10/why-2014-wont-be-the-warmest-year-on-record/
Well if that is their claim, then all the human generated CO2 added cannot be said to be either good or bad. All that extra CO2 may save the human race if in 30-50 years there is a major volcanic eruption. The CO2 induced warming will be the only thing stopping another mini ice age.
So unless they can accurately predict volcanic eruptions of the next 100 years, global warming can be good.
But according to David Ridley, an atmospheric scientist at the Massachusetts Institute of Technology in Cambridge and lead author of the new study, classic climate models weren’t adding up.
They weren’t? That’s not what the warmists have been saying!
IMHO, I think geothermal/volcanic might be a more significant source of heat, maybe even the “missing” hiatus heat.
IPCC AR5 TS.6 admits they have low certainty about the oceans below 2,000 m, which is 50% of it. I believe there is a lot of geothermal heat flux through the thin crust that comprises the ocean floor. The Antarctic ice sheet that floated away a year ago was found to have volcanic hot spots under it. Glaciers melt from the warm earth not the cold air. And I recall a recent article where a long string of volcanic vents were discovered along ocean floor plate ridges.
It’s those unknown unknowns that just keep popping up.
The AGW/CCC argument is basically warming equals CO2 because what else could cause it? Well, just look around. Not that all difficult to find other natural possibilities.
http://www.writerbeat.com/articles/3713-CO2-Feedback-Loop
Several decades ago, early sixties, my cousins and I were stacking hay bales at my grandfather’s farm outside Las Animas, CO. As it was a hot summer’s day we had brought along one of those canvas covered water bags. For those who haven’t seen one, there’s a picture on one of Jackson Browne’s albums. Before you filled the bag you had to saturate the canvas with water. The water would evaporate and cool the contents, water, wine, beer. The evaporating water would approach the wet bulb temperature determined by the ambient humidity, maybe 10 or 15 F below the ambient dry bulb. (90 F, 30% – 67 F WBT) One of my cousins dropped the bag from several rows up. Don’t do that. Split that bag wide open. No forgiveness in incompressible water.
I think this is what Miatello means by a refrigerator rather than a blanket or greenhouse. The water cycle cools the earth. In a refrigeration cycle the ammonia or Freon is compressed and when it expands its temperature drops. The water cycle absorbs energy and cools when it releases it through evaporation w/o a sensible temperature increase.
My only objection to Miatello’s paper is his suggestion that entropy has something to do with randomness. Not so. Entropy is about heat & energy. Order/disorder, random/not random have exactly zero to do with it.
Entropy says that a closed system will degrade from a higher energy level to lower energy level. If I brought order into it I would say from a high energy/highly disordered state to a low energy/less disordered state. Pretty much the opposite of the creation science interpretation. Greater order and lower energy are entropy’s natural flow.
http://principia-scientific.org/publications/PSI_Miatello_Refutation_GHE.pdf
Terribly “unsettling” paper from 2012, yet.