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 suffering from units confusion. What are the conversion factors between Pinatubos, Hiroshima blasts, and microwave oven-hours? Sounds like a job for Willis!
i swear the T at the end of Chris as in Turney was a typo, tho i like it now that i see it.
Tom O’Donnell says: “Hard Quantitative estimates”.Wow!!! In the aerospace manufacturing world we have a term for that type of information: SWAG (for Simple Wild Assed Guess).
I prefer the term “P.O.O.M.A.” That stands for Preliminary Order Of Magnitude Approximation.” Really, it does.
“Yes,. of course, it’s the volcanoes, or the aerosols, or the Trade Winds, or the Polar Vortex, etc. The Warmistas are increasingly desperate to explain the complete failure of the CO2 models. When they get round to blaming the Jews, we will know that the end is at hand.”
I think it will end with blaming witchcraft from sceptics?
This study is farcicle.
If they are under-estimating the effects of volcanism because previously tropospheric eruptions were not considered significant. Then they need to INCREASE the 20th century cooling effect too. Yet it’s already too strong as the lower panel in their own graph shows.
http://wattsupwiththat.files.wordpress.com/2012/02/ngeo2098-f1.jpg
When they remove what they consider to be effect of Mt P they get left with a warming bump. Current values are already too big!
This is just more stupid manipulation. They attempt to invoke an effect to explain post 2000 ‘hiatus’ without applying the same thing to pre-2000.
It’s just like other attempts to blame the hiatus on recent drop in solar activity without acknowledging that this also means the late 20th c. warming was in part due to a sustained period of high solar activity.
It’s amazing the way these so-called scientists are willing to throw the scientific method under a bus in order to save the planet from a non existent problem.
There is only one conclusion to be drawn from that: their primary motivation in this work is not one of science.
Santa Baby @ur momisugly 10:51pm
Sorry, couldn’t resist;
The coincidence that these volcanoes spewed the right amount of ashes, the deep ocean absorbed just the right amount of heat at the same time is truly unprecedented… /sarc
Since the science that predicted warming was sold to the public as beyond question any explanation is a blatant fraud by any standards outside that of climate science. Lets face it , even the most basic Fourier analysis shows regular cycles which are not replicated in a single one of the models which are therefore by definition proven wrong before we even start to examine correlation. A correlation which fails so dismally that now even the distorted no change interpreted as no change at all rather than no change from the normal variability is now better than the computer models.
It is interesting to note how the surplus of explanations now has appeared on the warmist side. A couple of years ago sceptics seemed to produce a surplus of explanations for the warming, and now, we see the same happening to explain the lack of it.
Was there any student of climate who did not already know volcanic eruptions cause cooling? Where’s the news in this story?
This work is based on the KISS principle, Keep It Simple Stupid.
A volcano’s impact on temp, wind shifts and the like are concepts simple enough to understand by the majority of those that grasp at straws so they keep it up with simple solutions
My wife keeps telling me that I have a problem with admitting fault when she was right and I was wrong. If I know that she is correct I usually don’t try and think of another reason why I was wrong but want to make it sound like I was right after all because it just makes me look even more like an ………. I just shut up and get on with it. Worked for more then 30 years now, not sure if those temp cycles work in a marriage also, we’ll see.
It seems to me that the CO2 bandwagon lead followers have a similar problem with admitting the hypothesis is wrong, but they keep on trying to justify their flawed position.
Hey fellas it is like marriage, when you are wrong you are wrong and you better shut up.
It seems there is a discontinuity (inadvertently?) factored into the algorithms at around 15 years ago: before this, the effects of volcanic eruptions were accurately accounted for, but not since that time.
–
Thankfully, the warming hiatus has brought it to the attention of the climate science aficionados. Hopefully, at last, the ‘science’ is ‘settled’.
Oh, how the stupidity burns…
Let me see if I’ve got this straight so far…..
If ONLY: volcanos stopped erupting, sunspot numbers stopped falling, trade winds stopped being too strong or too weak (apparently both phenomena cause cooling…LOL!), the PDO stopped its 30-year cool cycle, La Lina cycles stopped, China stopped emitting coal particulates, oceans stopped warming, clouds stopped reflecting solar radiation, ocean evaporation stopped its cooling effect, Antarctic ice extents stopped growing, the Arctic Vortex stopped…..vortexing and monkeys stopped flying out my butt.. well…then… CAGW climate model projections would be spot on…
Got it… Carry on…/sarc
Pass the Duck Tape… My head is exploding….
What a load of BS – known & certified warmists trying to defend the Pause. They have absolutely zero credibility amongst anyone who would be naturally skeptical of such claims. They have everything to gain & nothing to lose by defending their CAGW meme, even if the data doesn’t support it.
Guys, we are not buying it !
I think I should publish a paper stating that the bulk of the warming from 1975 to 2000 was due to the lower than normal volcanic activity in that period.
If any of the idiotic warmists challenge this I can then ask them to produce the volcano date that they must have to hand for the 20th century to disprove it as otherwise they could not make the claims they have made in this paper.
Without this data, this paper amounts to stating that volcanoes have a net cooling effect.
Who would have thunk it!
Alan
The Afar reagion in northern Ethiopia has been active and emiting particulates and gases since people first lived in the region. Is the factored in to the models? It will eventually become an in-land sea, and that event will be interesting for the climate and the world!
Santer thinks the hiatus is a detective story. I’d say climate science in general is like a detective story at this time while it’s still in its infancy as a science. And as usual The Gardener (CO2) gets blamed before all suspects have even been properly interviewed 😉 But even though their current purpose is to strengthen their case against the gardener, I think it’s good for the science that they at least have started interviewing the other suspects!
“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.”
I wonder how much much reminding all the idiots require?.
Rather waste time modeling, it seems the focus should be on finding a standardize way
of measuring dust in the atmosphere.
That might reduce the hopeless bad guessing and it might encourage some people to be less
forgetful.
As to Steve B ‘s query , when will they scrap the models and get back to real science?
My guess is , when Hades reaches a tipping point ( Hell freezes over!)
I haven’t trademarked that joke, so feel free to use it.
SAMURAI @ur momisugly 11:47pm
Alright, apart from;
volcanos stopped erupting, sunspot numbers stopped falling, trade winds stopped being too strong or too weak (apparently both phenomena cause cooling…LOL!), the PDO stopped its 30-year cool cycle, La Lina cycles stopped, China stopped emitting coal particulates, oceans stopped warming, clouds stopped reflecting solar radiation, ocean evaporation stopped its cooling effect, Antarctic ice extents stopped growing, the Arctic Vortex stopped…..vortexing and monkeys stopped flying out my butt.. well…then…
…what else have the Roman’s done for us?
I’ve just removed the affects of Krakatoa in 1883 from my Megabucks5 computer model thus eliminating the cooling it caused and I find that from 1883 until the start of the hiatus that the global temperature has only increased by only 0.06 dec C per decade. I’ve also projected forward using the Megabucks5 Astrological Future Probe Chaos Destroyer Model and that gives a further 0.06×8.5=0.5 deg warming between now and the 2100. The Logic Consolidator and Travesty Override module has asked what to do with the heat that should have gone into the ocean instead of being reflected away by the newly identified reflective volcanic aerosols and I have to admit I am struggling, which is my own personal travesty. I need more funding!
Just one thing wrong with this theory. There hasn’t been any major eruptions since Pinatubo in 1991. This is shown beautifully in this atmospheric transmission curve:
http://www.esrl.noaa.gov/gmd/grad/mloapt.html
Note that this was actually measured at the Sacred Site of Mauna Loa, the only true fount of CO2 data.
From the abstract of Santer et al. (2014), they’re claiming the volcanos explain only 15% of the divergence between models and observations, with large uncertainties, and they had to limit their study to only two models, the ones with more realistic responses to volcanos (the others had unrealistic responses apparently):
“We show that climate model simulations without the effects of early twenty-first-century volcanic eruptions overestimate the tropospheric warming observed since 1998. In two simulations with more realistic volcanic influences following the 1991 Pinatubo eruption, differences between simulated and observed tropospheric temperature trends over the period 1998 to 2012 are up to 15% smaller, with large uncertainties in the magnitude of the effect. To reduce these uncertainties, better observations of eruption-specific properties of volcanic aerosols are needed, as well as improved representation of these eruption-specific properties in climate model simulations.”
What all you people have missed is the obvious- it’s worse than we thought.
Because of global warming, the terrestrial volcanoes have been more active than usual, causing particles in the atmosphere to stop sunlight getting through, and deep sea volcanoes (which don’t cause aerosol particles) have been less active, adding less heat to the oceans, which have nonetheless absorbed the excess heat from the surface and are getting warmer (mostly in places where there are no instruments to capture the phenomenon, but take my word for it).
Terrestrial (subduction zone) volcanoes produce much more CO2) than deep sea (spreading zone) volcanoes, so like I said- it’s worse than we thought.
I don’t know why it’s happening, I’m not a climate scientist.
Mark my words (he said portentously) – you’ll all be sorry when the grants stop and the warmists (who are all much smarter than you) come to take your jobs!
That is good advice. I would add to that and say that we should also recall that all (or almost all) of the multiple causes of climate change can make the temps go up or make the temps go down.
Case in point; I thought volcanoes produced a lot of CO2 which the warmists say increases the temperature of the earth. Now we have both up and down from the volcano. (of course, some alarmists say that only man-released CO2 can do magic warming but surely that is known to be ridiculous)