Researchers find models must account for volcanic eruptions to accurately predict climate change.
From:MIT Joint Program on the Science and Policy of Global Change
By the late 1990s, scientists had observed more than two decades of rapid global warming, and expected the warming trend to continue. Instead, despite continuing increases in greenhouse gas emissions, the Earth’s surface temperatures have remained nearly flat for the last 15 years. The International Panel on Climate Change verified this recent warming “hiatus” in its latest report.
Researchers around the globe have been working to understand this puzzle — looking at heat going into the oceans, changes in wind patterns, and other factors to explain why temperatures have stayed nearly stable, while greenhouse gas concentrations have continued to rise. In a study published today in Nature Geoscience, a team of scientists from MIT and elsewhere around the U.S. report that volcanic eruptions have contributed to this recent cooling, and that most climate models have not accurately accounted for the effects of volcanic activity.
“This is the most comprehensive observational evaluation of the role of volcanic activity on climate in the early part of the 21st century,” says co-author Susan Solomon, the Ellen Swallow Richards Professor of Atmospheric Chemistry and Climate Science at MIT. “We assess the contributions of volcanoes on temperatures in the troposphere — the lowest layer of the atmosphere — and find they’ve certainly played some role in keeping the Earth cooler.”
There are many components of the Earth’s climate system that can increase or decrease the temperature of the globe. For example, while greenhouse gases cause warming, some types of small particles, known as aerosols, cause cooling. When volcanoes erupt explosively enough, they enhance these aerosols — a phenomenon referred to as “volcanic forcing.”
“The recent slowdown in observed surface and tropospheric warming is a fascinating detective story,” says Ben Santer, the lead author of the study and a climate scientist at Lawrence Livermore National Laboratory. “There is not a single culprit, as some scientists have claimed. Multiple factors are implicated. The real scientific challenge is to obtain hard quantitative estimates of the contributions of each of these factors to the so-called slowdown.”
The researchers verified the cooling phenomenon by performing two different statistical tests to determine whether recent volcanic eruptions have cooling effects that can be distinguished from the intrinsic variability of the climate. The team found evidence for significant correlations between volcanic aerosol observations and satellite-based estimates of both tropospheric temperature and sunlight reflected by the particles off the top of the atmosphere.
“What’s exciting in this work was that we could detect the influence of the volcanic aerosols in new ways. Using satellite observations confirmed the fact that the volcanic particles reflected a significant amount of the sun’s energy out to space, and of course losing energy means cooling — and the tropospheric temperatures show that too,” explains Solomon, who is also a researcher with MIT’s Joint Program on the Science and Policy of Global Change. “There are still uncertainties in exactly how big the effects are, so there is more work to do.”
Alan Robock, a professor of environmental sciences at Rutgers University and a leading expert on the impacts of volcanic eruptions on climate, says these findings are an important part of the larger climate picture. “This paper reminds us that there are multiple causes of climate change, both natural and anthropogenic, and that we need to consider all of them when interpreting past climate and predicting future climate.”
“Since none of the standard scenarios for evaluating future global warming include volcanic eruptions,” Robock adds, “this paper will help us quantify the impacts of future large and small eruptions when they happen, and thus better interpret the role of humans in causing climate change.”
This research was led by a team at Lawrence Livermore National Laboratory and builds upon work Solomon conducted in 2011, finding that aerosols in an upper layer of the atmosphere — the stratosphere — are persistently variable and must be included in climate models to accurately depict climate changes.
The research was supported by the U.S. Department of Energy.
h/t to Roger Sowell
For reference, here is the associated paper; (h/t Greg)
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2098.html
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I’m confused. Can someone tell me what puts more CO2 into the atmosphere people or volcanos? This must also be confusing to Santor.
People emit more than volcanoes. Look at the links. However we know the amount emitted by US plants, and European plants, but little about Chinese plants. If Pinatubo cooled the Earth by .5 degree based on 17mm tons SO2, what were we doing when we emiited 15mm tons annually, and when Europe was emitting 20mm tons annually? And when we added scrubbers and reduced emissions by 20-25mm tons annually, what was the likely result? It’s a no-brainer. The fact that hundreds of scientists can’t figure this out is the mystery.
Clean Air Act – 12mm ton decrease EVERY YEAR
http://en.wikipedia.org/wiki/Mount_Pinatubo
http://www.epa.gov/airmarkets/quarterlytracking.html
Human SO2 emissions compared with SAOT.
Notice none of the sulfur emissions reach the stratosphere and need volcanic eruptions with force to achieve this. Unless SO2 emissions reach the stratosphere there will be no global affect on temperatures.
The real reason for the hiatus is shown below, global clouds.
With the change in PDO complementing it well with weaker and less El Nino events, combined with stronger and more La Nina events.
It will only be matter of time when the AMO becomes increasingly negative (over the next decade) and increasingly difficult for a warming planet in future. The AMO has recently reached negative and is at what I call neutral values. (very close to zero)
Right and we know all this because… we sort of think so? You present 2 hypotheses neither of which is supported by any evidence. First you think “none” of it reaches the stratosphere, and it can’t have an effect if not in the stratosphere. Those are just convenient assumptions. Where’s the proof.
This is the correct link to the above post for global clouds.
The other is deliberately exaggerated by twice the forcing, to show a huge difference for comparison only. This type of forcing is the extreme range and very unlikely to be this much. Almost like the equivalent 4c global warming up to the year 2100 from the climate models.
Uh, people… do you realize what you all have done?
In one small thread, you’ve totally destroyed the whole “climate science” charade AND MIT.
Keep up the good work.
Just the Facts, I noticed the same thing you did. No warming since 1993.
Brodie Johnson says:
February 24, 2014 at 12:17 pm
“You present 2 hypotheses neither of which is supported by any evidence. ”
I have only presented observed data and the expected forcing on cloud albedo shown by satellite data and hadcrut3 global temperatures.
http://climate4you.com/images/TotalCloudCoverVersusGlobalSurfaceAirTemperature.gif
The scientific evidence supports declining global cloud levels with warming global temperatures and since global cloud levels have stabilized there has been no warming.
If global warming that occurred was caused by decreasing SO2 human emissions then why did almost all the rise occur in just 2 step ups? The global warming step ups occurred straight after strong El Nino events, hence the links above that I have shown. The PDO positive phase represents more stronger El Nino events and the PDO negative phase represents fewer weaker El Nino events.
None might not be the correct word, but negligible or unnoticed probably fairer. The scientific evidence shows the SAOT satellite data is not detecting the massively much bigger human SO2 levels. Hence, human SO2 levels are not reaching the stratosphere.
Brodie Johnson says:
February 24, 2014 at 12:17 pm
“it can’t have an effect if not in the stratosphere”
I was referring too it cant have a global affect and it does have a small localized regional affect. The problem being SO2 is very short lived in the troposphere with it being washed out and falls to the ground as acid rain.
The 2 step up in global temperatures link.
http://www.woodfortrees.org/plot/hadcrut3gl/from:1982/plot/hadcrut3gl/from:1997.5/trend/offset:-0.05/plot/hadcrut3gl/from:1987/to:1996.5/trend/offset:-0.05
Virtually all the temperature rise down to just the 2 events.
Brodie Johnson says:
February 24, 2014 at 12:10 pm
Matt G says:
February 24, 2014 at 12:11 pm
There is a huge difference between SO2 injected in the stratosphere by volcanic explosions like the Pinatubo and SO2 injected by humans in the lower troposphere: the residence time.
Human SO2 emissions have an average residence time of 4 days before raining out or going down as dry deposit.
Stratospheric SO2 has an average residence time of 1-2 years, because the growth of water drops around the SO2-SO3-H2SO4 molecules is a lot slower in the stratosphere – far less water vapour.
That makes that the 0.5°C drop in temperature from the Pinatubo”s SO2 injection translated to the continuous human emissions gives near zero change in temperature. Anyway far less than what the climate models have implemented because they needed a scapegoat to explain the 1945-1975 temperature drop with increasing CO2 levels.
As the SO2 emissions dropped in Europe and North America and increased in SE Asia, there is hardly any change in human SO2 emissions and hardly any stratospheric injection in the past 1.5 decade by volcanoes. Thus this story -again- has no bearing in reality…
Like the Berlin Wall CAGW will suddenly collapse one day and then we will hear zilch about climate science. The progressives jump on something hype it till the point of manipulation then leave it for good. How much do we hear about home ownership and expanding loans to the disadvantaged anymore? Of course after the Liberal Media throw a brief tantrum and question the motives of scientists and even the validity of current science itself they will move on to the next issue. The average Joe still opens windows before a tornado so it will take quite a while for these myths to be tossed in the dumpster of history!
Hmmm….hang on. Why is it volcanic activity is capable of halting the 20thC temp rise when it was going up, but incapable of stopping it in the first place? Are volcanoes a new discovery, because I distinctly remember them in the 20th century.
/Derp
http://en.wikipedia.org/wiki/List_of_large_volcanic_eruptions_of_the_20th_century
Ferdinand Engelbeen says:
February 24, 2014 at 1:21 pm
Agreed,
The links I gave show stratospheric SO2 has an average residence time of about 2 years. Hence, even this is far too short for any long term climate affects.
I am not convinced that volcanic activity has even a tiny fraction of the effect of changes in solar irradiance. Even when Tambora in 1815 blew, releasing something like 60 cubic miles of debris and 3 trillion tons of CO2 into the atmosphere, the climatic effects (cooling, incidentally, despite the huge CO2 emission, dozens of times more than ever released by human activuity) lasted only about two years. No trend there.
Well, if my almost ZEV Subaru Impreza, is a cause of climate change, then for sure the occasional volcano is. So just how occasionally erupting is Haleakala in Hawaii ? Anyone got a quick handle on just how many currently active erupting volcanoes there are on earth ??
I notice we now have more polluting carbon on earth than we used to have. In Sierra Leone, they dug up 153 carats of carbon in an unstable (room T&P) form. Not as big as the 969 all time largest alluvial diamond ever found and just a dust grain compared to the Cullinan 3107 carat stone.
Diamond is unstable at room temperature and pressure, and apparently prefers to be graphite. Luckily, the atoms are packed so tightly, that it takes a lot of temperature to agitate them enough to crumble down to soot. I dunno if bucky balls are also unstable at RT&P.
So be careful of your diamonds, lest the gat carbon taxed to death.
Professor Ian Plimer wrote a whole book called Heaven and Earth, listing many factors that could affect the climate, including volcanoes. The idea that climate scientists can identify, measure and model all these factors is just ridiculous. They are finally realising Prof Plimer was right.
http://www.amazon.com/Heaven-Earth-Warming-Missing-Science/dp/1589794729
“the Earth’s surface temperatures have remained nearly flat for the last 15 years”. That’s a bit of an exaggeration; the temperature trend has been less steep, but certainly not flat. Fact is, the linear temperature trend in recent years is still positive, even if you take the unusually warm El Nino year 1998 as your starting point. 2000-2009 is the warmest decade in the instrumental record. 1998 now ranks third warmest in the instrumental record; 2010 and 2005 were both warmer.
Gerry Beauregard says: February 24, 2014 at 5:12 pm
That’s a bit of an exaggeration; the temperature trend has been less steep, but certainly not flat.
No, you are wrong, there has been no “Global Warming” since the late 1990s or early 2000s, The Pause, which has been acknowledged by all loosely credible news sources, i.e.:
In fact, looking at the Werner Broznak’s recent article, the Pause in each major temperature data set is as follows:
WoodForTrees.org – Paul Clark – Click the pic to view at source[/caption]
For GISS, the slope is flat since July 2001 or 12 years, 6 months.
For Hadcrut3, the slope is flat since July 1997 or 16 years, 6 months.
For Hadcrut4, the slope is flat since December 2000 or 13 years, 1 month.
For Hadsst3, the slope is flat since December 2000 or 13 years, 1 month.
For UAH, the slope is flat since October 2004 or 9 years, 3 months. (goes to December using version 5.5)
For RSS, the slope is flat since September 1996 or 17 years, 4 months.”
Shown graphically, that looks like this:
[caption id="" align="alignnone" width="640"]
Hiding Co2 global warming is volcanoes activity. The “Hiatus”
Somehow, I knew the so called “Climate Scientists” would fall back on volcanoes when I saw a satellite photo of a active volcano in Chile. (WUWT). But there is one Big Problem with [their] “Hiatus” All of the recent volcanoes activity started after the recent decline of “world temperature reading” How will they spin that?
Big Problem with there……. should read Big Problem with their…..
Three words: Out Of Africa
Volcanic contribution to Aerosol Optical Depth (AOD) is extremely minor compared to the dusts of the African deserts. But then the group of scientists attached to the above research seem bent on studying tiny things while ignoring large things. Really large things. Like oceans and vasts deserts, and trade winds, and jet streams…
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.12.9025&rep=rep1&type=pdf
“This paper reminds us that there are multiple causes of climate change, both natural and anthropogenic, and that we need to consider all of them…”
—
There most certainly are multiple natural causes of climate change, and they keep coming up with new ones, like aerosols and volcanoes. Since the science is settled, why can’t they provide us with a definitive list of them all instead of inventing new ones whenever they need to explain why their models fail to match reality?
The contribution of volcanos to global cooling is exactly zero. I proved this in my book “What Warming?” that has been out since 2010. You will find the explanation on pages 17 to 21 and it is not complicated. I started by studying that Pinatubo cooling about much nonsense has been written. One article by Self et al. in the book “Eruptions and Lahars of Mount Pinatubo” in 1996 stands out. They report warming in the lower stratosphere at 16 to 22 kilometer height. When a volcano erupts that is where the hot eruption products immediately ascend. The stratosphere warmed at first but that was followed by cooling within the year. That is observation but then they jump over and transfer this stratospheric cooling to the troposphere because of a mistaken identity. They show an out of context segment of the satellite temperature curve that includes the 1991 El Nino peak followed by La Nina cooling. It so happens that by coincidence the Pinatubo eruption coincided with the 1991 El Nino peak. El Nino peaks are followed by La Nina valleys and it was only natural for these guys to think that Pinatubo caused cooling an appropriate that La Nina as Pinatubo cooling. You can’t argue with that because this is an example of one. Besides, he is an expert on volcanos and ought to know. But then he gives me a hint about what is going on. Not knowing anything about ENSO hethinks that Pinatubo just suppressed an El Nino and pontificate that ” Pinatubo climate forcing was stronger than the opposite warming of El Nino event or anthropogenic greenhouse gases…” But then he admlts to some puzzling observations and starts to wonder why surface cooling is “…clearly demonstrated after some eruptions (for example, Gunung Agung, Bali, in 1963) and not others – for example, El Chichon, Mexico, in 1982.” Interesting, isn’t it? What would you do with that? What I did was to look up El Chichon on the global temperature chart and discovered that its eruption coincided with a La Nina valley and was immediately followed by the 1983 El Nino peak. No sign that it even tried to overcome that El Nino, and no convenient La Nina valley in a location that could be appropriated for a volcanic cooling event. That was the clue. I checked out the locations of a number of other volcanic eruptions with reference to the El Nino peaks that are displayed in many global temperature curves. They are the teeth of the sawtooth pattern that some people want to disappear. It turned out just as I suspected: if an eruption was close to an El Nino peak they appropriated the La Nina valley that followed for its volcanic cooling. If the eruption was near the bottom of a La Nina valley there was no La Nina near to appropriate and they were stuck. Gunung Agung was followed by an abrupt descent into a La Nina valley that was appropriated for its cooling. But the greatest eruption of the twentieth century was Katmai (Novarupta) in Alaska. Its timing coincided with the beginning of an El Nino and it left no trace of any cooling whatsoever.There were also intermediate cases whose timing fell in the downward slope between an El Nino peak and a La Nina valley. They ended up with substandard cooling. Among them is Krakatao. From this it is quite certain that volcanic cooling simply does not exist and such “volcanic cooling” incidents marked on temperature charts are simply misidentifications of La Nina valleys that by chance happened to be where theory predicts a volcanic cooling ought to be.
“… aerosols in an upper layer of the atmosphere — the stratosphere — are persistently variable…”
—
“Persistently variable” sounds like an oxymoron to me. Something can be persistent or variable but not both. However, if people can refer to something as “constantly changing,” then I guess “persistently variable” could also be valid. Come to think of it, “persistently variable” is a good description for the theory of climate change. The theory has been changing faster than the climate, so it’s certainly not “settled science.”
To: Ferdinand Engelbeen
You are correct that the residence time of anthropogenic SO2 is too short to be comparable to volcanic SO2 “pound for pound”, and in fact must be an order of magnitude smaller. My speculation was therefore ill-informed. However, 1) global SO2 emissions are on the order of 100mm tons annually, taking into account petroleum as well as coal, and areas other than Europe and the US, and these emissions over 20 years are ~100 times greater than the emissions from the Mt. Pinatubo eruption (17mm tons); and 2) most of the emissions are in near populated areas, where most temperature records are taken 3) the paper below states that the “horizontal extent” of human SO2 emissions is “1000 to 2000km or more” so it is not unreasonable to speculate that a significant amount might end of 10 km higher than where it was emitted, and 4) there is the possibility of convection carrying emissions into the stratosphere. Also the paper referenced in this thread discusses post-Pinatubo eruptions where the amount of SO2 was an order of magnitude smaller (say 2mm tons, with less of it in the stratosphere since the plumes are not as high for smaller eruptions), and yet postulates this was enough to offset a 20% increase in CO2.
My instinct (admittedly with no scientific basis) is that in Beijing, the smog is bad enough that everyone wears a mask. When I am at the beach on a 75 degree day, and the sun goes behind a cloud, I put my shirt back on. The smog in LA was much worse prior to catalytic converters and emissions regulations. If you can see smog it is going to make it cooler. Just common sense. But by and large we have eliminated smog in the US and Western Europe. In St. Peterburg I saw more smog than in the last 40 years in any city in the US. These are all anecdotes and prove nothing. However they suggest something that needs to be investigated further.
http://www.ecd.bnl.gov/steve/pubs/ClimateForcingAerosols1992.pdf
mwhite says:
February 24, 2014 at 10:50 am
“The lunar eclipse record indicates a clear stratosphere over the past decade, and that this has contributed about 0.2 degrees to recent warming.”
——————————————————————————-
Where do you see a recent warming of 0.2 in the last decade?