Volcanoes helped offset man-made warming: study

Feb 23, 2014 by Mariette Le Roux

Volcanoes spewing Sun-reflecting particles into the atmosphere have partly offset the effects of Man's carbon emissions over a 15-year period that has become a global-warming battleground, researchers said Sunday.

A so-called hiatus in warming since 1998 has pitched climate sceptics against mainstream scientists.

While temperatures have risen relentlessly—13 of the l4 warmest years on record occurred since the start of the century—they tracked far below the increase in man-made greenhouse gases.

This gap between the expected and actual temperatures has been cited by sceptics as proof that human-induced is either a green scare or bad science.

But a study in the journal Nature Geoscience said volcanic eruptions helped explain the apparent warming slowdown.

Researchers using satellite data found a link between surface temperatures and the impact from nearly 20 volcanic eruptions since 2000.

Sulphuric droplets disgorged by the volcanoes reflected sunlight and slightly cool the lower atmosphere, they said.

The effect of these "aerosols" accounted for as much as 15 percent of the gap between expected and measured temperatures between 1998 and 2012, according to the team's figures.

"The 'warming hiatus' since 1998 has a number of different causes," study co-author Ben Santer of the Lawrence Livermore National Laboratory in California told AFP by email.

"The cooling caused by early 21st century is one of the causes."

Other explanations for the "hiatus" have been a bigger-than-expected takeup of atmospheric heat by the ocean, or a decline in solar activity.

Blockbuster eruptions, notably that of Mount Pinatubo in the Philippines in 1991, were known to have discernible cooling effects on Earth's surface.

But volcanoes have not featured in the "hiatus" debate mainly because there had been no major eruptions since the mooted pause began in 1998, only smaller ones whose impact is harder to measure.

- Better models needed -

This is a gap, as it left computer models of climate change incomplete, the new study suggested.

"Better observations of eruption-specific properties of volcanic aerosols are needed, as well as improved representation of these... in climate model simulations," it said.

Global warming sceptics have pointed to the "hiatus" as proof of flaws in models used to predict warming and thus play a key role in driving policies to tackle climate change.

They contend that these models exaggerate the heat-trapping effect from carbon dioxide (CO2) emitted by fossil fuel burning.

Santer said the new findings "do not support" such an argument.

"We've been lucky that a natural cooling influence (an uptick in 21st century volcanic activity) has partly counteracted human-caused warming," he said.

"We do not know how volcanic activity will evolve over the coming decades, and thus we do not know how long our luck will continue."

Experts generally agree that Earth is on track for greatly exceeding the maximum two degrees Celsius (3.6 degrees Fahrenheit) of warming targeted in UN climate negotiations.

Last year the level of (CO2) in the atmosphere crossed a threshold of 400 parts per million (ppm)—a level never experienced by humans.

CO2 concentrations are rising at two or three ppm per year, driven especially by the burning of coal in emerging economies.

Commenting on the study, Piers Forster, a professor of at the University of Leeds, said it confirmed that volcanoes contributed to the slowdown, but could not be the only cause.

"Volcanoes give us only a temporary respite from the relentless warming pressure of continued increases in CO2," he added.

Explore further: Pacific trade winds stall global surface warming—for now

add to favorites email to friend print save as pdf

Related Stories

Ozone pact helped cool the planet, study reports

Nov 10, 2013

A slowdown in global warming that climate sceptics cite in favour of their cause was partly induced by one of the world's most successful environment treaties, a study said on Sunday.

Dire outlook despite global warming 'pause': study

May 19, 2013

A global warming "pause" over the past decade may invalidate the harshest climate change predictions for the next 50 to 100 years, a study said Sunday—though levels remain in the danger zone.

Recommended for you

Tropical Storm Genevieve forms in Eastern Pacific

Jul 25, 2014

The seventh tropical depression of the Eastern Pacific Ocean formed and quickly ramped up to a tropical storm named "Genevieve." NOAA's GOES-West satellite captured an infrared image of the newborn storm ...

NASA maps Typhoon Matmo's Taiwan deluge

Jul 25, 2014

When Typhoon Matmo crossed over the island nation of Taiwan it left tremendous amounts of rainfall in its wake. NASA used data from the TRMM satellite to calculate just how much rain fell over the nation.

User comments : 31

Adjust slider to filter visible comments by rank

Display comments: newest first

RichardBlumenthal
1.8 / 5 (9) Feb 23, 2014
Vocanoes appear to produce a lot of lasting heat. http://www.scienc...2815.htm
orti
2.7 / 5 (14) Feb 23, 2014
Hehe, I love it. It's hiding in the deep ocean, in the places we haven't been monitoring. No, it's the winds in the southern sea, or maybe the volcanic aerosols. But it's happening and it's man-made and its time for extreme action – 95% certain, settled science.
ubavontuba
1.9 / 5 (9) Feb 23, 2014
Hehe, I love it. It's hiding in the deep ocean, in the places we haven't been monitoring. No, it's the winds in the southern sea, or maybe the volcanic aerosols. But it's happening and it's man-made and its time for extreme action – 95% certain, settled science.
LOL.

The relentless search for the "missing heat" by crackpot AGW "scientists" is beginning to smack of desperation...

Maggnus
3.3 / 5 (12) Feb 23, 2014
A trio of idiots appear to have trouble understanding the means by which science teases out the complexity of climate. Considering who they are, I am not surprised.

Funny thing is, orti actually has it mostly right. Partially it is because of heat transfer to the deep ocean. That is occurring, in part, because of the winds in the southern seas. Part of it is the volcanic aerosols.

And yes, it is 95% certain, and yes, it is also settled science.
aksdad
2.5 / 5 (11) Feb 23, 2014
They contend that these models exaggerate the heat-trapping effect from carbon dioxide (CO2) emitted by fossil fuel burning.

Santer said the new findings "do not support" such an argument.


If Santer, et al. can only explain 15% of cooling with volcanoes, then how does their study account for the other 85% of "cooling" that seems to be "masking" the real human-CO2-caused warming that he and Maggnus and others believe is occurring? Answer: it doesn't.

The IPCC AR5 draft initially displayed this graph of how poorly the global climate models are performing when compared to observations of the real world:

http://wpmedia.op...mp;h=507

Of course it was removed when it was turned over for review by governments (politicians). It was too strong an indictment of the failure of the models. Unquestionably the models have tuned their sensitivity to CO2 too high as CO2 continues to increase but temperatures have not.
dav_daddy
2.1 / 5 (11) Feb 24, 2014
Other explanations for the "hiatus" have been a bigger-than-expected takeup of atmospheric heat by the ocean, or a decline in solar activity.


OMG!! Anyone who dares mention increased solar output as part of the reason for elevated temps is met with disdain and many links to studies showing no change to the solar output.

We have come full circle now it was sceptics proposing with no evidence, now its the AGW crowds turn to trot this out (along with imaginary volcanos because reality doesn't hive with their data.

More evidence the whole global warming panic is a bunch of crap. I seriously think its something hardwired into us the belief that we must take action or ruin the planet. Anyone else old enough to remember the 70's when the panic was that another ice age could kick off at any moment?
Agomemnon
2.3 / 5 (9) Feb 24, 2014
I myself am a CO2 advocate. I'm working for doubling the CO2 in the atmosphere which will be a great benefit to all life on this planet.
Rimino
Feb 24, 2014
This comment has been removed by a moderator.
Maggnus
4 / 5 (12) Feb 24, 2014
Askdad, that is a load of misleading questions you ask there! First of all they account for "only" 15% of the slowdown in recorded surface temperature plots across the planet. The remaining 85% is going elsewhere and they do not allude to where. Even orti got that part right, albeit accidentally.

There is no cooling, and nothing in this paper (or anywhere else except a few denialist blogs and the new ice age proponents) says anything different. So you are using the fallacy of a red herring.

And finally, to this:
Unquestionably the models have tuned their sensitivity to CO2 too high as CO2 continues to increase but temperatures have not.
SOME data sets show that SURFACE temperatures are RISING SLOWER than early predictions, BUT they are STILL RISING WITHIN THE ERROR BARS!

The extent to which some will misrepresent data continues to astound.

antigoracle
2.3 / 5 (7) Feb 24, 2014
Is it their claim that there has been an increase in volcanic activity in the last 15 years?
Or just another AGW lie.
Maggnus
3.9 / 5 (7) Feb 24, 2014
Is it their claim that there has been an increase in volcanic activity in the last 15 years?
Wow an actual question! Yes, their study has identified 17 specific small eruptions since 2000 that have contributed more aerosols into the atmosphere than has been accounted for in climate models.
TheGhostofOtto1923
1 / 5 (5) Feb 24, 2014
Forgive me but ... Isn't this a major factor that hasn't been included in any AGW models? So was I wrong in assuming they had this all figured out (because they said so) or what? Is it possible that I may be repeating this sentiment at some time in the near future? (No doubt)
Wow an actual question! Yes, their study has identified 17 specific small eruptions since 2000 that have contributed more aerosols into the atmosphere than has been accounted for in climate models
Um... If they missed these in just the last decade, is it possible that they've missed more in earlier decades when observation was even less comprehensive?
Maggnus
4 / 5 (8) Feb 24, 2014
Forgive me but ... Isn't this a major factor that hasn't been included in any AGW models?
No. Unpredictable events like eruptions can't be included in such predictive models
So was I wrong in assuming they had this all figured out (because they said so) or what? Is it possible that I may be repeating this sentiment at some time in the near future? (No doubt)
This does nothing to change the basics. As eruptions can't be predicted, they can't be included in predicting changes to climate either. They can only be considered in hindsight.
Um... If they missed these in just the last decade, is it possible that they've missed more in earlier decades when observation was even less comprehensive?
No.
antigoracle
2 / 5 (6) Feb 25, 2014
Is it their claim that there has been an increase in volcanic activity in the last 15 years?
Wow an actual question! Yes, their study has identified 17 specific small eruptions since 2000 that have contributed more aerosols into the atmosphere than has been accounted for in climate models.

And, how about prior to 2000?
Maggnus
4 / 5 (8) Feb 25, 2014
And, how about prior to 2000?
Prior to 2000, those 17 eruptions had not happened. The last major eruption was Pinatubo in 1991and the affects of that eruption on the Earth's atmosphere were well documented.
TheGhostofOtto1923
1.6 / 5 (5) Feb 25, 2014
No. Unpredictable events like eruptions can't be included in such predictive models
Correct. But they seem to be one of a number of major factors which haven't been included in climate models, which scientists have used to determine with certainty that human activity is overheating the planet.

These major factorials seem to pop up once every few weeks, is what I'm saying. And I don't mind repeating myself every few weeks either.
No.
Yes, quite possibly. What makes you so certain? Observation has only improved in the last decade and look what they missed.
Prior to 2000, those 17 eruptions had not happened. The last major eruption was Pinatubo
You sure? They missed AT LEAST 17 in only 10 years.
TheGhostofOtto1923
1.5 / 5 (4) Feb 25, 2014
Maybe they missed a few of these.

"Approximately 1,100 mud volcanoes have been identified on land and in shallow water. It has been estimated that well over 10,000 may exist on continental slopes and abyssal plains.

"2003: Achim J. Kopf estimated 1.97×1011 to 1.23×1014 m³ of methane is released by all mud volcanoes per year, of which 4.66×107 to 3.28×1011 m³ is from surface volcanoes.[6] That converts to 141–88,000 Tg/yr from all mud volcanoes, of which 0.033–235 Tg is from surface volcanoes."
Unpredictable events like eruptions can't be included in such predictive models
No but they can be estimated, and they have to be, because of their impact on climate per the article. Apparently estimates are low.
Maggnus
3.9 / 5 (7) Feb 25, 2014
But they seem to be one of a number of major factors which haven't been included in climate models, which scientists have used to determine with certainty that human activity is overheating the planet
Such as?
What makes you so certain? Observation has only improved in the last decade and look what they missed.
Fallacy of an excluded middle. Natural sources of CO2 are considered in models, as they should be. These smaller than major eruptions added more than the average.
You sure? They missed AT LEAST 17 in only 10 years.
That we are talking about them means they didn't miss them.
Maybe they missed a few of these.
These do not add aerosols to the atmosphere. It is the extra aerosols from an above average number of mid-sized eruptions that we are talking about.
No but they can be estimated, and they have to be, because of their impact on climate per the article.
And so they are, excepting above average activity.
TheGhostofOtto1923
1.3 / 5 (4) Feb 25, 2014
Such as?
Sorry I haven't kept a record of all the times I have said 'You mean they missed something else?' I'm just not that interested. But it was 5 or 6. Major. So far.
These smaller than major eruptions added more than the average.
'The average.' The average of the ones they belatedly discovered.
That we are talking about them means they didn't miss them.
?? And so since we are not talking about the ones they missed prior to 2000 then those didn't happen? You make no sense.
These do not add aerosols to the atmosphere
They are factors which may or may not have been included in climate models. Scientists haven't demonstrated their right to be so conclusive. These additional factors indicate this.
excepting above average activity
-which implies that they have missed far more.

Falsify this statement: "Prior to 2000 there were no volcanic eruptions which hadn't been discovered which significantly affected climate."
Maggnus
3.9 / 5 (7) Feb 25, 2014
But it was 5 or 6. Major. So far.
Such as?
The average of the ones they belatedly discovered.
No, the average that is used given the understanding that the Earth is a dynamic place.
And so since we are not talking about the ones they missed prior to 2000 then those didn't happen? You make no sense.
Which did they miss? You commented that they missed 17, yet here we are talking about them. You a bit disconnected?
They are factors which may or may not have been included in climate models.
Do you understand what "averaging" means?
which implies that they have missed far more.
No such implication has been made.
Falsify this statement: "Prior to 2000 there were no volcanic eruptions which hadn't been discovered which significantly affected climate."
Fallacy. There, falsified.
antigoracle
1 / 5 (6) Feb 25, 2014
And, how about prior to 2000?
Prior to 2000, those 17 eruptions had not happened. The last major eruption was Pinatubo in 1991and the affects of that eruption on the Earth's atmosphere were well documented.

Maggnus the one with all the answers.
So, one more question.
The rate of warming from the 1960's to 1998 is almost exactly that from 1910 to 1940, when human CO2 was negligible in comparison. So, what was responsible for this earlier warming?
thermodynamics
4.4 / 5 (7) Feb 25, 2014
The Myth: "The GCM software keeps missing things."

The reality: The GCM software is complex and includes almost everything that is known. However, it might require adjustment. As an example, this article on eruptions shows that they have to include smaller scale eruptions to have a higher-fidelity response. They have included major eruptions for the past decade and they do a good job of showing the historical impact. However, they were not sure where they had to cut the line on eruption size. Now they have a better handle. They will probably adjust thresholds downward on other issues as they learn more.

This is completely different from thinking they have not included volcanoes.
TheGhostofOtto1923
1 / 5 (5) Feb 25, 2014
Such as?
Sorry Im not playing and I dont bullshit. Stay tuned for the next ones. Oh and write this one down.
No, the average that is used given the understanding that the Earth is a dynamic place.
The average implies a dynamic which scientists have no business categorizing as an AGW certainty.
Which did they miss? You commented that they missed 17, yet here we are talking about them. You a bit disconnected?
No dweeb Im right here. They missed 17 in 10 years. How about the previous 10 years? How about the 10 years before that? Have they only been able to catch the 17 because of monitoring improvements within the last 10 years?

Many questions and doubts come to mind.
Do you understand what "averaging" means?
Do you understand what 'insufficient data' means? How about 'loss of confidence'?
No such implication has been made
It can be made and it has. But not by AGW spin doctors.
There, falsified.
Translation: Ill believe what I want to despite the evidence.
TheGhostofOtto1923
2.3 / 5 (4) Feb 25, 2014
Maggnus the one with all the answers
...that maggnus wants to hear.

Heres my take on global warming.
1) Its real.
2) Theres nothing that can be done to affect it with todays tech.
3) The threat and the hype are very useful for funding the development of tech necessary for upcoming geopolitical readjustments; for instance the middle east and north africa will soon be uninhabitable except in sealed environmental megastructures like the burj dubai.
4) This tech is also vital to future efforts to settle mars and elsewhere off-planet, in sealed environmental megastructures, which is probably its principal Ursache.

Humans are a crisis-driven species. We will never do anything unless we HAVE to. And we HAVE to establish independent colonies elsewhere. The survival of what may be the only intelligent species in the entire universe depends on it.

Who knows, perhaps the whole petrol infrastructure was created to FORCE us to emigrate. They incubate eggs in much the same way yes?
Maggnus
4.4 / 5 (7) Feb 25, 2014
Sorry Im not playing and I dont bullshit. Stay tuned for the next ones. Oh and write this one down.
Happy? You said there have been "major factors". in fact:
But it was 5 or 6. Major. So far.
Yet when I ask you what, you can give no answer. Sounds like bullshit to me Ghost.
The average implies a dynamic which scientists have no business categorizing as an AGW certainty.
What certainty was categorized exactly, that you feel they had "no business categorizing"? That there will be warming? That co2 causes it? What is the issue, in your mind?

You are playing a game Ghost. They did not miss 17 eruptions in 10 years, that is a complete misrepresentation of what has occurred here. And I think you know that! So pardon me if my response to your grandstanding is a bit on the glib side.

The modelling of the climate is HARD, and picking the flyshit out of the pepper in regards to the minutia of the predictions serves no purpose except to sow doubt and misinformation.
Maggnus
4.4 / 5 (7) Feb 25, 2014
Heres my take on global warming.
1) Its real.
Agreed.
2) Theres nothing that can be done to affect it with todays tech.
I disagree. Things are being done, despite the actions of the organized deniers.
3) The threat and the hype are very useful for funding the development of tech necessary for upcoming geopolitical readjustments; for instance the middle east and north africa will soon be uninhabitable except in sealed environmental megastructures like the burj dubai.
Maybe, but that does not excuse doing nothing!
4) This tech is also vital to future efforts to settle mars and elsewhere off-planet, in sealed environmental megastructures, which is probably its principal Ursache.
Which is really your verus voluntas right?
TheGhostofOtto1923
1.2 / 5 (5) Feb 25, 2014
you can give no answer. Sounds like bullshit to me Ghost
Well to me it sounds like I remember using this same punchline 5 or 6 times but dont specifically remember what the subject matter was, because Im really not interested. Nor am I interested in what you think particularly.
What is the issue
You think perhaps if I repeat myself so many times using different words each time, that what I say will begin to look like something you agree with? I dont think so.
You are playing a game Ghost
You forced my hand.
They did not miss 17 eruptions in 10 years, that is a complete misrepresentation of what has occurred here
"Researchers using satellite data found a link between surface temperatures and the impact from nearly 20 volcanic eruptions since 2000."

-IOW they failed to include ('missed') this data in their original models. Data which explained a complete 'hiatus'.

"Equivocate: use ambiguous language so as to conceal the truth or avoid committing oneself."
TheGhostofOtto1923
1.5 / 5 (4) Feb 25, 2014
Things are being done
Nothing that will have any effect whatsoever on temperature for the near term.
Maybe, but that does not excuse doing nothing!
We are certainly not 'doing nothing' as I indicated. We are spending billions on energy storage and production tech, as well as advanced materials development (membranes, coatings, insulation, radiation shielding, high temp superconductors, super-strong construction materials, etcetcetcetc) which just happen to be directly applicable to future exploits in space. Surprise.

Unfortunately none of this will have any effect on global warming. It will help us to adapt however.

This is equivalent to staging a cold war in order to force the production of 8000++ tons of fissiles, which just happens to be the most valuable material we now possess. Not to mention the rocketry, electronics, warmaking capability, medical advances, etcetcetcetc.

See how these things Work?
really your verus voluntas
Sorry I dont speak dutch.
TheGhostofOtto1923
1.5 / 5 (4) Feb 25, 2014
You are playing a game Ghost
Thats all you guys ever do here in these AGW threads. I am just trying to fit in.
Maggnus
4.3 / 5 (6) Feb 25, 2014
That's ok Ghost, I don't particularly give a fiddlers ass what you think either, and I could care even less about whether or not you agree with me. Your admission that you're playing a game scores points, but the fact that you seem unable to understand the import of these researchers' findings makes me wonder about you.

Sorry I dont speak dutch.
Latin actually, its a legal term that means "the real reason" or "the real purpose".


Whatever, peace.
mosahlah
1.8 / 5 (5) Feb 26, 2014
Unleash the Excuses!
ScooterG
1.7 / 5 (6) Feb 28, 2014
" - Better models needed - "

Finally! An intelligent and accurate observation from the AGW industry.