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(Sydney Morning Herald)   Scientists say volcanic eruptions have slowed global warming in recent years, leading to hope for a rebound in numbers of pirates   (smh.com.au) divider line 40
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518 clicks; posted to Geek » on 24 Feb 2014 at 9:06 AM (30 weeks ago)   |  Favorite    |   share:  Share on Twitter share via Email Share on Facebook   more»



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2014-02-24 09:09:03 AM
Interglacial warming, how werk it.
 
2014-02-24 09:32:15 AM
Hawai'ian virgin reportedly nervous.
 
2014-02-24 09:41:21 AM
s2.quickmeme.com


 
2014-02-24 09:50:28 AM
Humans:  We are damaging nature irrevocably!  We need to totally change the way we do everything or the planet will die!
Nature:  You think so?  Hold my beer.  *faaaaaaart*  There.  Fixed.

Nature is more redneck hunter than west coast liberal.
 
2014-02-24 09:54:33 AM

HotIgneous Intruder: Interglacial warming, how werk it.


Well, it doesn't work by volcanoes, which have a net cooling effect, so I have no idea what you're saying.

It's also bizarre that the news article (but not the original paper from Nature Geoscience) claims: "Eruptions of at least 17 volcanoes since 2000, including Nabro in Eritrea, Kasatochi in Alaska and Merapi in Indonesia, ejected sulphur whose sun-blocking effect had been largely ignored until now by climate scientists, it said."  Unless they mean that only those volcanoes were under the radar because they're small, as climate forcings have been tracking volcanic effects for decades.  From NASA:

data.giss.nasa.gov

The gray line with the big spike in 1992?  That's Pinatubo, and it dropped the global temperature by ~0.2K for a year or two.  (Volcanic ash is potent, but settles relatively quickly.)

www.giss.nasa.gov
 
2014-02-24 10:10:00 AM
This is FARK, dude. Science and religion have no place here. Only the power of sarcasm compells you!
 
2014-02-24 10:24:06 AM
People have been talking about this for some time. IIRC the past 20 years or so had an unusually high amount of volcanic eruptions which due to off gas and shooting dust into the atmosphere acted like a miniature nuclear winter. Some suggested that this was hiding the worst effects of global warming and that once the eruptions lowered to historical levels we would get a sudden shot of GW. (the global climate catastrophe not the president...not sure which is worse)
 
2014-02-24 10:25:17 AM
Yes, deniers, we know about things like this.  No, it doesn't make the theory untrue, non-serious, or silly.  These kinds of changes cause what is known as "annual variation" which can be accounted for, and is only relevant to people excitedly cherry-picking data.
 
2014-02-24 10:26:05 AM

nocturnal001: People have been talking about this for some time. IIRC the past 20 years or so had an unusually high amount of volcanic eruptions which due to off gas and shooting dust into the atmosphere acted like a miniature nuclear winter. Some suggested that this was hiding the worst effects of global warming and that once the eruptions lowered to historical levels we would get a sudden shot of GW. (the global climate catastrophe not the president...not sure which is worse)


"Hiding?"

Not "counterbalancing?"
 
2014-02-24 10:27:42 AM

chimp_ninja: HotIgneous Intruder: Interglacial warming, how werk it.

Well, it doesn't work by volcanoes, which have a net cooling effect, so I have no idea what you're saying.

It's also bizarre that the news article (but not the original paper from Nature Geoscience) claims: "Eruptions of at least 17 volcanoes since 2000, including Nabro in Eritrea, Kasatochi in Alaska and Merapi in Indonesia, ejected sulphur whose sun-blocking effect had been largely ignored until now by climate scientists, it said."  Unless they mean that only those volcanoes were under the radar because they're small, as climate forcings have been tracking volcanic effects for decades.  From NASA:

[data.giss.nasa.gov image 649x477]

The gray line with the big spike in 1992?  That's Pinatubo, and it dropped the global temperature by ~0.2K for a year or two.  (Volcanic ash is potent, but settles relatively quickly.)

[www.giss.nasa.gov image 850x603]


There are so many stupid arguments that this data shoots down, but that doesn't mean they're going away.
 
2014-02-24 10:27:50 AM

chimp_ninja: HotIgneous Intruder: Interglacial warming, how werk it.

Well, it doesn't work by volcanoes, which have a net cooling effect, so I have no idea what you're saying.

It's also bizarre that the news article (but not the original paper from Nature Geoscience) claims: "Eruptions of at least 17 volcanoes since 2000, including Nabro in Eritrea, Kasatochi in Alaska and Merapi in Indonesia, ejected sulphur whose sun-blocking effect had been largely ignored until now by climate scientists, it said."  Unless they mean that only those volcanoes were under the radar because they're small, as climate forcings have been tracking volcanic effects for decades.  From NASA:

[data.giss.nasa.gov image 649x477]

The gray line with the big spike in 1992?  That's Pinatubo, and it dropped the global temperature by ~0.2K for a year or two.  (Volcanic ash is potent, but settles relatively quickly.)

[www.giss.nasa.gov image 850x603]


I believe the point is that many CMIP5 models simulate volcanic eruptions using stratospheric AOD (Aerosol Optical Depth) datasets which only include the larger eruptions. Also, CMIP5 historical runs officially end in 2005. A few groups produced extended historical runs up to 2012 but plotting model output trends past 2005 in most cases requires use of the scenario future projection runs which don't include any observed data, and don't include any volcanic eruptions.

So I believe the point of the paper is to compare those standard CMIP5 runs with equivalents loaded with observed stratospheric aerosol information. Actually the result appears to be pretty small, predictably: around 0.02ºC/Decade I think.
 
2014-02-24 10:31:28 AM

sendtodave: nocturnal001: People have been talking about this for some time. IIRC the past 20 years or so had an unusually high amount of volcanic eruptions which due to off gas and shooting dust into the atmosphere acted like a miniature nuclear winter. Some suggested that this was hiding the worst effects of global warming and that once the eruptions lowered to historical levels we would get a sudden shot of GW. (the global climate catastrophe not the president...not sure which is worse)

"Hiding?"

Not "counterbalancing?"


Yes, because, here's the thing about greenhouse gasses, they don't go away when the Volcano is done.  And it's not like average temperatures aren't still going up, they're just not going up as fast.

But why am I arguing with you?  If you cared about being right, you wouldn't still be a denier at this late date.
 
2014-02-24 10:33:59 AM

sendtodave: nocturnal001: People have been talking about this for some time. IIRC the past 20 years or so had an unusually high amount of volcanic eruptions which due to off gas and shooting dust into the atmosphere acted like a miniature nuclear winter. Some suggested that this was hiding the worst effects of global warming and that once the eruptions lowered to historical levels we would get a sudden shot of GW. (the global climate catastrophe not the president...not sure which is worse)

"Hiding?"

Not "counterbalancing?"


Hiding is awkward phrasing perhaps. My coffee hasn't kicked in all the way. Counterbalancing would imply a net neutral effect, instead it's just a temporary thing.
 
2014-02-24 10:36:50 AM

nocturnal001: Hiding is awkward phrasing perhaps. My coffee hasn't kicked in all the way. Counterbalancing would imply a net neutral effect, instead it's just a temporary thing.


And not just temporary, it's also less dramatic in degree.
 
2014-02-24 10:37:14 AM
They might also be interested to know that I have pointed several mirrors at the sun when I was bored as an experiment, so there's that also....
 
2014-02-24 10:38:15 AM

dillengest: I believe the point is that many CMIP5 models simulate volcanic eruptions using stratospheric AOD (Aerosol Optical Depth) datasets which only include the larger eruptions. Also, CMIP5 historical runs officially end in 2005. A few groups produced extended historical runs up to 2012 but plotting model output trends past 2005 in most cases requires use of the scenario future projection runs which don't include any observed data, and don't include any volcanic eruptions.

So I believe the point of the paper is to compare those standard CMIP5 runs with equivalents loaded with observed stratospheric aerosol information. Actually the result appears to be pretty small, predictably: around 0.02ºC/Decade I think.


Danke.  That makes sense.  You'd think with the current satellite coverage it would actually be more work to calculate aerosol concentrations off of known eruptions, vs. just measuring it directly.  Maybe there's some hesitancy if it doesn't merge nicely with decades ago, when we had less sophisticated tools for this, but they need to get over that.

sendtodave: nocturnal001: People have been talking about this for some time. IIRC the past 20 years or so had an unusually high amount of volcanic eruptions which due to off gas and shooting dust into the atmosphere acted like a miniature nuclear winter. Some suggested that this was hiding the worst effects of global warming and that once the eruptions lowered to historical levels we would get a sudden shot of GW. (the global climate catastrophe not the president...not sure which is worse)

"Hiding?"  Not "counterbalancing?"


"Hiding" is probably more accurate, because volcanic aerosols have a reasonably short half-life in the atmosphere.  The majority of an eruption's effects linger for only a year or two-- even for something massive like Pinatubo, you can't spot a long-term impact in the temperature data above.  If volcanic activity goes back towards baseline amounts, that effect goes away and we're back to the points in the graph above where the gray line is effectively zero.  Then we're seeing full-strength greenhouse warming, vs. the 85% or so we're seeing now, according to these authors.
 
2014-02-24 10:39:57 AM

ikanreed: Yes, deniers, we know about things like this.  No, it doesn't make the theory untrue, non-serious, or silly.  These kinds of changes cause what is known as "annual variation" which can be accounted for, and is only relevant to people excitedly cherry-picking data.


i.chzbgr.com
 
2014-02-24 10:40:49 AM

nocturnal001: sendtodave: nocturnal001: People have been talking about this for some time. IIRC the past 20 years or so had an unusually high amount of volcanic eruptions which due to off gas and shooting dust into the atmosphere acted like a miniature nuclear winter. Some suggested that this was hiding the worst effects of global warming and that once the eruptions lowered to historical levels we would get a sudden shot of GW. (the global climate catastrophe not the president...not sure which is worse)

"Hiding?"

Not "counterbalancing?"

Hiding is awkward phrasing perhaps. My coffee hasn't kicked in all the way. Counterbalancing would imply a net neutral effect, instead it's just a temporary thing.


Can't we just fire up some volcanoes whenever we need some soot?

I mean, I grew up being scared of nuclear winter.  Now everyone is scared of heat.  It's like, guys, WE ALREADY HAVE A SOLUTION!
 
2014-02-24 10:41:40 AM

indarwinsshadow: ikanreed: Yes, deniers, we know about things like this.  No, it doesn't make the theory untrue, non-serious, or silly.  These kinds of changes cause what is known as "annual variation" which can be accounted for, and is only relevant to people excitedly cherry-picking data.

[i.chzbgr.com image 500x350]


Oh, look, someone who doesn't have a counter-argument.
 
2014-02-24 11:00:16 AM
New plan to deal with climate change: Keep going till the effect becomes almost too much for us to live in, then drill into Yellowstone, let that sucker off, and restore balance to the Earth.
 
2014-02-24 11:00:46 AM
tea baggers and deniers, it's always the tea baggers and the deniers.
 
2014-02-24 11:11:25 AM

sendtodave: nocturnal001: sendtodave: nocturnal001: People have been talking about this for some time. IIRC the past 20 years or so had an unusually high amount of volcanic eruptions which due to off gas and shooting dust into the atmosphere acted like a miniature nuclear winter. Some suggested that this was hiding the worst effects of global warming and that once the eruptions lowered to historical levels we would get a sudden shot of GW. (the global climate catastrophe not the president...not sure which is worse)

"Hiding?"

Not "counterbalancing?"

Hiding is awkward phrasing perhaps. My coffee hasn't kicked in all the way. Counterbalancing would imply a net neutral effect, instead it's just a temporary thing.

Can't we just fire up some volcanoes whenever we need some soot?

I mean, I grew up being scared of nuclear winter.  Now everyone is scared of heat.  It's like, guys, WE ALREADY HAVE A SOLUTION!


Yes, but then what do we do when the town is over run with Chinese needle snakes? Bring in some sort of Gorilla that thrives on snake meat? Preposterous.
 
2014-02-24 11:37:51 AM
i wouldn't be surprised if there are more pirates now then in any time in history.  and by pirates, i mean people on boats who attack other boats for bounty and/or ransom.

primarily because it is much cheaper to create a vessel capable of attack, the skill required and risk inherent have decreased, and there are much more goods on the sea.

/ it's already a fact that there are more slaves.  and by slaves, i mean real slaves, forced servitude.  not just farkers who don't want to be in the office today.
 
2014-02-24 12:21:24 PM

ikanreed: indarwinsshadow: ikanreed: Yes, deniers, we know about things like this.  No, it doesn't make the theory untrue, non-serious, or silly.  These kinds of changes cause what is known as "annual variation" which can be accounted for, and is only relevant to people excitedly cherry-picking data.

[i.chzbgr.com image 500x350]

Oh, look, someone who doesn't have a counter-argument.


2.bp.blogspot.com
 
2014-02-24 12:26:51 PM
So the answer to global warming is to detonate nukes directly above the magma chambers of stratovolcanoes.
 
2014-02-24 12:53:26 PM

ikanreed: Yes, because, here's the thing about greenhouse gasses, they don't go away when the Volcano is done.  And it's not like average temperatures aren't still going up, they're just not going up as fast.


1. You're assuming that greenhouse gases are at abnormally high levels.
2. You're assuming that greenhouse gases are the cause of higher temperatures.
3. You're assuming that temperatures are abnormally high.
 
2014-02-24 01:00:41 PM

WelldeadLink: 1. You're assuminghave learned through empircal observation that greenhouse gases are at abnormally high levels.
2. You're assuminghave learned through empircal observation and an understanding of incredibly basic scientific principals that greenhouse gases are the cause of higher temperatures.
3. You're assuminghave learned through empircal observation

 that temperatures are abnormally high.

The fact that you're assuming things doesn't mean I am.

Any one of those 3 is an extraordinarily well demonstrated point at this point, and at best you can misrepresent by context shifting.
 
2014-02-24 05:08:32 PM

HotIgneous Intruder: Interglacial warming, how werk it.

chimp_ninja: HotIgneous Intruder: Interglacial warming, how werk it.

Well, it doesn't work by volcanoes, which have a net cooling effect, so I have no idea what you're saying.

It's also bizarre that the news article (but not the original paper from Nature Geoscience) claims: "Eruptions of at least 17 volcanoes since 2000, including Nabro in Eritrea, Kasatochi in Alaska and Merapi in Indonesia, ejected sulphur whose sun-blocking effect had been largely ignored until now by climate scientists, it said."  Unless they mean that only those volcanoes were under the radar because they're small, as climate forcings have been tracking volcanic effects for decades.  From NASA:

[data.giss.nasa.gov image 649x477]

The gray line with the big spike in 1992?  That's Pinatubo, and it dropped the global temperature by ~0.2K for a year or two.  (Volcanic ash is potent, but settles relatively quickly.)

[www.giss.nasa.gov image 850x603]


I'm sure we'll vehemently disagree very shortly, but yes.  If Pinatubo was so massive of particulate matter ejector and that ejecta only had a limited time span in the atmosphere as a blocking element, it's real hard to put the blame on volcanoes at much higher latitudes with much less upper atmospheric ejecta. I'm sure someone will try to justify the amounts and locations and point out more coincidences, but to put the credit/blame on volcanoes for just this last 17 years worth of atmospheric warming hiatus is really weak.
 
2014-02-24 07:13:35 PM
i2.wp.com


Praise him you denier heathens!
 
2014-02-24 07:16:01 PM

DoctorOfLove: tea baggers and deniers, it's always the tea baggers and the deniers.


Not everyone can be part of the mindless masses on Fark.
 
2014-02-24 08:35:40 PM

Valiente: Hawai'ian virgin reportedly nervous.


I don't see why she's so nervous. She may be the first person saved from being turned into charcoal by global warming.

The more volcanoes erupt, the more pirates there are. While throwing virgins into volcanoes works the other way, by appeasing the volcano gods and adding to the global warming trend.

To put it another way, thank God we ran out of virgins before we killed off all the global cooling aerosols. We're doing enough damage as it is.
 
2014-02-24 08:36:54 PM

SVenus: HotIgneous Intruder: Interglacial warming, how werk it.chimp_ninja: HotIgneous Intruder: Interglacial warming, how werk it.

Well, it doesn't work by volcanoes, which have a net cooling effect, so I have no idea what you're saying.

It's also bizarre that the news article (but not the original paper from Nature Geoscience) claims: "Eruptions of at least 17 volcanoes since 2000, including Nabro in Eritrea, Kasatochi in Alaska and Merapi in Indonesia, ejected sulphur whose sun-blocking effect had been largely ignored until now by climate scientists, it said."  Unless they mean that only those volcanoes were under the radar because they're small, as climate forcings have been tracking volcanic effects for decades.  From NASA:

[data.giss.nasa.gov image 649x477]

The gray line with the big spike in 1992?  That's Pinatubo, and it dropped the global temperature by ~0.2K for a year or two.  (Volcanic ash is potent, but settles relatively quickly.)

[www.giss.nasa.gov image 850x603]

I'm sure we'll vehemently disagree very shortly, but yes.  If Pinatubo was so massive of particulate matter ejector and that ejecta only had a limited time span in the atmosphere as a blocking element, it's real hard to put the blame on volcanoes at much higher latitudes with much less upper atmospheric ejecta. I'm sure someone will try to justify the amounts and locations and point out more coincidences, but to put the credit/blame on volcanoes for just this last 17 years worth of atmospheric warming hiatus is really weak.


Why don't you try reading some actual papers for once? Like Solomon et al., 2011 (in Science); Fyfe et al., 2013 (in GRL); or the paper in TFA, Santer et al., 2014 (Nature Geoscience).

This increase in aerosol loading is not present in the RCP forcings and will cause spurious warming in the model projections.

It alone is not the whole story, but taking it in combination with the other observed issues like coverage bias and ENSO negative conditions/deeper OHC accumulation, and the models and obs converge nicely.
 
2014-02-24 09:37:57 PM

Jon Snow: Why don't you try reading some actual papers for once? Like Solomon et al., 2011 (in Science); Fyfe et al., 2013 (in GRL); or the paper in TFA, Santer et al., 2014 (Nature Geoscience).

This increase in aerosol loading is not present in the RCP forcings and will cause spurious warming in the model projections.

It alone is not the whole story, but taking it in combination with the other observed issues like coverage bias and ENSO negative conditions/deeper OHC accumulation, and the models and obs converge nicely.


Here is the Mauna Loa Apparent Transmission dating back to 1960. I'll let the viewers here decide whether the raw data presented here reflects a marked change in light due to aerosol.
www.esrl.noaa.gov
Link to actual source graphic at NOAA.gov.

Now, perhaps Santer can manage to create some short term data charts that make it seem it substantiates his conclusions but I for one do not see a trend of any volcano based aerosol blockage that seems much different from a baseline trend one can pretty well draw the the eye.  

You can see two things.  One, a marked area when big volcanoes go off. Two, a small trend to slightly dimmer skies.  Santer, Solomon, Neely and others are taking that slight trend and magnifying it into a giant mirror, patting themselves on the back and generally blowing aerosol smoke at everyone else.
If you focus on a small enough trend, one can get whatever curves you have to armwave your theory into acceptance.

Let us all know when the IPCC officialy global climate models use actual aerosol data instead of a modeled version.

/it's models, all the way down.
 
2014-02-24 09:40:08 PM
http://www.  esrl.noaa.gov/gmd/webdata/grad/mloapt/mlo_transmission.gi f
Link doesn't like to post in text.
 
2014-02-24 11:04:54 PM

SVenus: Here is the Mauna Loa Apparent Transmission dating back to 1960. I'll let the viewers here decide whether the raw data presented here reflects a marked change in light due to aerosol.
[www.esrl.noaa.gov image 850x525]
Link to actual source graphic at NOAA.gov.

Now, perhaps Santer can manage to create some short term data charts that make it seem it substantiates his conclusions but I for one do not see a trend of any volcano based aerosol blockage that seems much different from a baseline trend one can pretty well draw the the eye.


Oh, wow.

This is denialist "science" in a nutshell.

"I  haven't bothered to actually read any of the papers detailing the extensive observational evidence on the subject at hand, but I did look at a graph online and try to eyeball it."

You do know there are entire branches of scientific investigation that are relied upon precisely because "that doesn't seem right" and "it doesn't look that way to my naked eye" are so misleading, don't you? They're called physics and statistics.

Are you farking kidding me?

You can see two things.  One, a marked area when big volcanoes go off. Two, a small trend to slightly dimmer skies.  Santer, Solomon, Neely and others are taking that slight trend and magnifying it into a giant mirror, patting themselves on the back and generally blowing aerosol smoke at everyone else.

So walk me through your "thought process" here.

The denialist blogs you get all of your "science" from point to a slight divergence to recent increases in temperature relative to CMIP5 models.

You even acknowledge the fact there is a demonstrable increase in volcanic aerosol dimming that is unaccounted for in the forcings used by the CMIP5 models, which should cause the model projections to run hotter than the obs.

But when several different groups have actually attempted to estimate the impact of this uncaptured aerosol forcing on surface temperature output from the CMIP5 models relative to observations, you whine because they use the CMIP5 models?

How does that make any sense whatsoever?

If you focus on a small enough trend, one can get whatever curves you have to armwave your theory into acceptance.

Using physics-based models with input from direct observations is literally the opposite of curve-fitting, you dolt.

Let us all know when the IPCC officialy global climate models use actual aerosol data instead of a modeled version.

Historical atmospheric aerosol values are generated using process and chemistry models based on observational data from ice cores and other deposition records, industry inventory records, etc. And these data sets are validated against real world data before they're used in climate models.

/it's models, all the way down.

Guess what, bud? It's "models all the way down" in pretty much every field of science. A mercury thermometer is just a model-based estimate of temperature. Laboratory mice are hugely imperfect models of the human body. Hell, Stefan-Boltzman is a goddamn model.

The immensely disgusting thing is that if you're still actively doing anything remotely like science in your real life, you're using models literally every day and you well know it.

Oh, and one more thing:

One, a marked area when big volcanoes go off.

If you bothered to read Santer et al., the response of the system to the larger volcanoes in the models vs. the obs gives us confidence that the former are getting the TCR broadly correct, which allows us to place higher confidence in their response to the persistent low-level volcanism that is absent from the RCP forcings.
 
2014-02-25 01:08:21 AM
Jon Snow:
If you bothered to read Santer et al., the response of the system to the larger volcanoes in the models vs. the obs gives us confidence that the former are getting the TCR broadly correct, which allows us to place higher confidence in their response to the persistent low-level volcanism that is absent from the RCP forcings.

 OK, so they're getting the TCR "broadly correct".
Nevertheless, there has been a pause for over a decade, so they went looking for a cause and claim the sunlight ain't getting down here.
So why was there a horrendously fast rate of warming just before 2000 but not after?
If temperature is so sensitive to the difference before and after 2000, why didn't we freeze all of Australia after those two big eruptions?

Here's a graph with estimated energy losses. Click for details and you can ask questions.
wattsupwiththat.files.wordpress.com
 
2014-02-25 08:09:28 AM

Jon Snow: Guess what, bud? It's "models all the way down" in pretty much every field of science.


And this is why I'm pretty damn confident you have failed in any way to convince anyone who's not already on your side.

There are two sciences to my mind.  Theoretical, and applied.
With theoretical, you have all sorts of models based on real world observations.
With applied, you put your theories to the test. You can show your results.

The theory behind volcanoes cooling off the planet is about as old as the science of geology itself.
I believe it.
Trying to manipulate tiny decadal fluctuations in the minute fraction of volcanic ejecta to show significant changes in the global climate in the face of the huge changes when significant ejecta gets thrown into the proper levels of the atmosphere is absolutely arguable.

But here's where I have a problem with this particular model. To verify, you need a good global climate model that can hindcast. There isn't one.
Oh, YOU think you have one.  But as we all know, all the global climate models have overestimated the warming that happened.
Oh, wait, that's what this paper was intended to do... make the broken climate models fit the data they weren't exactly fitting before.
I'm not in the model making business, but I think that's what you might call "confirmation bias". No wonder they need so much computing power.
First you put in the global climate model, then you put in your model on top of that model, add your new data "estimates" to the mix, and churn until your error bars on the first model start shrinking. Tweak the estimate of the actual influence of the tiny trend of aerosols a bit, churn the data again, and see how that curve matches up.
Ten or twenty runs later, you have a curve you're willing to show to others.
Just not the process or the actual tweaking you've done to get your result. Brilliant!

tl;dr Santer's 17 years has come and gone, and this paper is what he's going to try to use to convince folks what we're seeing isn't a real hiatus in warming.
 
2014-02-25 09:46:57 AM

WelldeadLink: Nevertheless, there has been a pause for over a decade


This is a conflation of two different issues.

1. The claim that global warming has "paused" or "stopped" or global temps have not increased is based on cherry picking a start date that includes a monster El Niño, as well as relying on data sets that have incomplete spatial cover.

If you look at the satellite temperature record, or surface instrumental records that account for missing coverage in the Arctic (where it's warming the fastest), the "pause" does not exist.

2. There has been, however, a small divergence between the multimodel ensemble mean of climate projections vs. the observational record over recent years. However, observations remain within the 95% uncertainty range of the models, and even perfect models will see a divergence from perfect observations over a large number of realizations. So the meaningfulness of such a divergence, even if it became statistically significant, is still pretty questionable.

But it's not just surface temperatures that we've noticed a change in. We have observational evidence for an unanticipated increase in moderate volcanic aerosol dimming. We have observational evidence for increased ocean heating of the deep ocean at the expense of the upper ocean and surface (coinciding with the predominantly ENSO negative conditions of the tropical Pacific).

When you take these factors (observational coverage bias, moderate volcanism, ENSO negative conditions/deep ocean heating), the models and observations come into very good agreement.

When you look at all of the evidence, rather than focusing on one small part, a consistent picture emerges. And this picture does not at all call into question the fundamental physics of radiative forcing and planetary balance.

so they went looking for a cause and claim the sunlight ain't getting down here.

The increase in aerosol loading of the stratosphere is simply what the observations show. No one had to "go looking for a cause" and "claim" this, it's what the data show. And to reiterate, this is not the only thing going on, and is actually responsible for only about a third of the model-obs disagreement.

So why was there a horrendously fast rate of warming just before 2000

Recovery from Pinatubo and ENSO positive conditions lead to warming from the early 90s to the mid-2000s slightly above what would have been expected based on GHGs alone. This was noted at the time.

 but not after?

It's basically the same processes, but in reverse. Instead of recovery from volcanic cooling, we've seen a small increase in cooling. Instead of ENSO positive conditions, we've seen predominantly ENSO negative conditions (which suppress surface warming and increase heating of the deep ocean). And the bias in observational coverage happens to be largest when you look at 1998 to present trends than any other time.

If temperature is so sensitive to the difference before and after 2000, why didn't we freeze all of Australia after those two big eruptions?

This makes no sense to me. Want to try that again?
 
2014-02-25 10:07:09 AM

SVenus: There are two sciences to my mind.  Theoretical, and applied.


The idea that one uses models and the other doesn't is absurd.

With theoretical, you have all sorts of models based on real world observations.
With applied, you put your theories to the test. You can show your results.


So your claim is now that "theoretical" science is untestable? Seriously?

NASA modeled the impact of the Pinatubo explosion on global temperatures before the results from the observational data were in, and its prediction was accurate to within a thousandth of a degree.

Upper stratospheric cooling is a confirmed "test" of anthropogenic greenhouse warming. There are any number of "tests" that have confirmed we broadly understand the climate system, in terms of multidecadal changes in energy balance.

Trying to manipulate tiny decadal fluctuations in the minute fraction of volcanic ejecta to show significant changes in the global climate in the face of the huge changes when significant ejecta gets thrown into the proper levels of the atmosphere is absolutely arguable.

This is an argument from personal incredulity. You can apply the same silly "logic" to disbelieving the results of the entire field of particle physics.

But here's where I have a problem with this particular model. To verify, you need a good global climate model that can hindcast. There isn't one.

That's absurd.

But as we all know, all the global climate models have overestimated the warming that happened.

That's absolutely false.

i.imgur.com

This is observed temperature and three runs from three different climate models of different sensitivities. Observations are lower than the higher sensitivity run, higher than the lower sensitivity run, and about dead on with the mid-range one.

You don't know what you're talking about, because you get your information from denialist blogs.

These data are freely available for you to download and plot yourself.

Oh, wait, that's what this paper was intended to do... make the broken climate models fit the data they weren't exactly fitting before.

The lack of aerosol forcing in recent years isn't a model problem. It's a problem with the inputs given to the models. And this paper in no way attempts to "make the models fit the data". It simply looks at what the effect of including the missing aerosol forcing has. That's it.

tl;dr Santer's 17 years has come and gone

Why don't you plot the UAH satellite data for the last 204 months and tell me what the sign of the linear regression is?

convince folks what we're seeing isn't a real hiatus in warming.

Warming has not stopped. Warming has been less than the multimodel mean in recent years. These are different but related issues. The first is simply not true (or at least is not robust to dataset choice), while the latter is well-explained using unquestionable changes in things like aerosols, ocean heat/ENSO, and our imperfect observational coverage.
 
2014-02-25 01:14:06 PM
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