Anthony Watts denies volcanic forcing

In another fit of Dunning-Krugeritis, conspiracy blogger Anthony Watts is touting Wondering Willis Eschenbach as an expert on volcanoes and climate. Sheesh.  He has picked up a cutesy intro to his copy and pastes of press releases, inserting the words "maybe they should have" in under his "claim" headlines. He's done this for three of his most recent articles. This time (archived here) it was:

Claim: NASA simulation indicates ancient flood volcanoes could have altered climate
From NASA/GODDARD SPACE FLIGHT CENTER and the “maybe they should have checked with Willis first” department comes this modeling claim: 

Rather than scientific experts asking Willis anything, Willis should be reading more science before putting digits to keyboards. Willis wrote an article a couple of weeks ago in which he was using volcanic eruptions to argue that the climate is self-correcting. He got it mostly wrong as usual. Perhaps an article for another day. (Among other errors, Willis confused forcings and feedbacks.) About the only things his article (archived here) had in common with this new paper were the words "climate" and "volcano" - proving (yet again) that:

• Anthony doesn't read the press releases he copies and pastes, or if he does he doesn't understand them
• Anthony Watts doesn't understand his blog articles from his "guest" essayists (that is, the freeby articles written by his fans), and probably doesn't read them
• Willis Eschenbach once got one thing right: even if Anthony had a year to digest the articles he posts on his blog, he wouldn't be able to tell if it was pseudo-science crap or the real thing
• Anthony Watts promotes fake experts (the No. 1 Telltale Technique of climate science denial).

As usual, Anthony didn't provide a link to the press release or the paper. (As usual, it wasn't hard to find.) The authors did research into ancient basalt flood volcanoes. These volcanic eruptions are enormous and are active for a very long time, but they don't usually eject material with the explosive force of volcanoes of the same type as Pinatubo. Pinatubo ejected material with such force it reached the stratosphere, which had a cooling effect.

How volcanic eruptions can cool the planet

The extent to which volcanic eruptions can cause cooling is determined by several related factors:

• Whether the gas reaches the stratosphere. If it stays in the troposphere it gets rained out easily. In the stratosphere, the gases can hang about for quite a bit longer. The effects from Pinatubo didn't disappear completely for several years.
• The latitude of the volcanoes. If they are at the equator, the troposphere is higher, so the gas has to be ejected with more force to reach the stratosphere. At the same time, equatorial volcanoes are more likely to affect both hemispheres.
• The composition of the gaseous material ejected - sulphur is the key. Sulfur dioxide (SO2) and hydrogen sulfide (H2S) react to produce sulfuric acid (H2SO4). This layer of sulphuric acid scatters some of the sun's infrared radiation and makes the stratosphere warmer, and the troposphere cooler.

Here's a diagram from NASA illustrating how the sulphuric acid forms in the stratosphere, reflecting more of the incoming solar radiation back out again, before it reaches the surface. Click to enlarge it:

Millions of tons of sulfur dioxide gas from a major volcanic eruption can reach the stratosphere. After converting to sulfuric acid droplets, these aerosols reflect energy coming from the sun, thereby preventing the sun's rays from heating Earth's surface. (Credit: Kristina Ruhlman/NASA)

Flood-basalt volcanoes could cause cooling

The team of scientists, led by Lori S. Glaze from NASA, were investigating the Columbia River Flood Basalts. In particular, they were interested in a volcanic eruption called Roza, in what is now Washington state. This occurred about 14.7 million years ago. Over about ten or fifteen years, it spewed out about 1,300 cubic kilometers of lava. The authors estimated that this could have injected 62 Mt of SO2/day into the stratosphere, which would have had a big impact on the climate at the time.

The press release at ScienceDaily.com gives some background to the work:

The magma that powers Pinatubo-type eruptions is thicker, and flows more slowly. Gas dissolved in this thick magma can't escape as easily, so when pressure is suddenly released at the beginning of these eruptions, it's like popping the cork on a bottle of champagne -- all the gas rushes out at once, producing an explosive eruption.

Since "fire-fountain" eruptions aren't as explosive, scientists wonder whether the gases from them are propelled high enough to reach the stratosphere, allowing the very large fire-fountain eruptions that produced the flood basalts to potentially alter the climate. The answer depends not only on how vigorous the eruption is -- taller fire fountains produce higher gas plumes -- but also on where the stratosphere begins.

The troposphere is higher at the equator and gets lower the further you get to the poles. That's because of temperature - warmer air takes up more space than the cold air at the north and south poles. So the closer a volcano is to the poles the greater the chance that the gases will reach the stratosphere, all other things being equal. With global warming, the troposphere is expanding upwards, so volcanoes have to have stronger ejections to reach the stratosphere.

The press release contrasts fire-fountain eruptions from the flood-basalt volcanoes, with eruptions from more explosive volcanoes.

Although flood-basalt eruptions were enormous, they were not as explosive as eruptions like Pinatubo. The molten rock (magma) in flood-basalt eruptions flowed easily. This allowed gas that was trapped in it to be released easily as well. This magma produces "fire-fountain" eruptions -- a fountain of lava rising hundreds of meters (hundreds of yards) into the air. Often these eruptions begin along a crack in Earth, called a fissure, up to several kilometers (a few miles) long, producing a dramatic glowing curtain of lava. Fire-fountain eruptions are seen on a smaller scale today in places like Hawaii and Mount Etna in Sicily, Italy.

The magma that powers Pinatubo-type eruptions is thicker, and flows more slowly. Gas dissolved in this thick magma can't escape as easily, so when pressure is suddenly released at the beginning of these eruptions, it's like popping the cork on a bottle of champagne -- all the gas rushes out at once, producing an explosive eruption. 

The scientists developed a model to see if a volcanic eruption like Roza could have spewed gases into the stratosphere, thereby causing cooling. They found that this was possible, although they don't yet know if that's what actually happened. From the press release:

The team verified their model by applying it to the 1986 Izu-Oshima eruption, a well-documented eruption in Japan that produced spectacular fire fountains 1.6 kilometers (almost a mile) high.

"This eruption produced observed maximum plume heights of 12 to 16 km (7.4 to 9.9 miles) above sea level," said Glaze. When the team input fountain height, temperature, fissure width, and other characteristics similar to the Izu-Oshima eruption into their model, it predicted maximum plume heights of 13.1 to 17.4 km (8.1 to 10.8 miles), encompassing most of the observed values.

"Assuming the much larger Roza eruption could sustain fire-fountain heights similar to Izu-Oshima, our model shows that Roza could have sustained buoyant ash and gas plumes that extended into the stratosphere at about 45 degrees north," said Glaze.

Although the team's research suggests the Roza eruption had the potential to alter climate, scientists still have to search for evidence of a climate change around the time of the eruption, perhaps an extinction event in the fossil record, or indications of changes in atmospheric chemistry or sea levels, according to Glaze.

Deniers "claim" it's not volcanoes

It's clear from Anthony Watts' "claim" headline that he doesn't "believe" that volcanoes can influence climate. I expect that he doesn't "believe" that Pinatubo and El Chichon had a temporary cooling effect, or that the Siberian Traps were probably what caused the biggest extinction event in Earth's history.

What does he think is the impact of volcanoes? Well, Anthony isn't in the business of putting forward any alternative hypothesis. He usually only goes as far as disputing science, without any alternative explanations.

Oh, there was the time that Anthony decided that it's Russian steampipes that are causing global warming. And the time that he reckoned OMG it's insects causing global warming. And then there are all the times that he posts articles claiming that it's not warming, that an ice age is upon us. Yeah, right!

Data source: GISS NASA

From the WUWT comments

Anthony's dogwhistle worked to some extent, though not a lot. Is he losing influence with deniers? Here are some of the thoughts floating about at WUWT:

Peter Hessellund Sørensen seems to think that the measured impact of Pinatubo is wrong. He's right that Anthony Watts has it wrong about large volcanic eruptions, however.

August 10, 2015 at 11:14 am
Bear in mind that the volcanic eruptions in historic times have been small compared to the eruptions in geologic times. The Toba volcano in indonesia 76 thousand years ago as an example created a lake 100 km long and 30 km wide and caused ash layers in India with 7 meters thickness. Concluding that just because miniscule volcanic eruptions like Pinatubo had no effect on climate the same is also true for the realy big volcanic eruptions of geological times is not justified.

Even staunch denier Salvatore Del Prete got it right for a change:

August 10, 2015 at 12:15 pm
If the volcanic eruption or eruptions are big enough they are for sure going to effect the climate as ALL of the past data so clearly shows. 

The "best guess" of TonyL is woefully wrong. All the greenhouse gases from volcanoes today aren't 1/100th of what we humans are emitting.

August 10, 2015 at 1:59 pm
What an amazing comment:
“There are other gases in volcanic plumes like water vapor and carbon dioxide. These gases don’t have significant effect on Earth because there is so much in the atmosphere already.
The general “best guess” is that volcanoes produce as much CO2 as all human activity (in round numbers). Here is a clear statement that it does not matter. Perhaps there is still a difference of opinion between geologists and the ClimateScience! types. 

Scientists have shown that "On average, human activities put out in just three to five days the equivalent amount of carbon dioxide that volcanoes produce globally each year." (Paper here.)


TA is ignorant or deluded. He or she doesn't even know that the world is warming, and is on pace to warm ten times faster than it has in the past 65 million years! He also doesn't know that the planet was warmer eons ago when CO2 was higher.

August 10, 2015 at 2:33 pm
Quoting the article: “The height of the boundary has also changed over time, as the contents of the atmosphere have changed. For example, carbon dioxide gas traps heat from the sun, so when there was more carbon dioxide in the atmosphere, temperatures were warmer and the tropopause was higher.”
There is more carbon dioxide in our present atmosphere than in the past, yet the temperatures are not warmer. Other times in the Earth’s past, the carbon dioxide levels have been higher than today, but the temperatures were lower.
I think the author assumes too much.
TA

fossilsage writes about "acetic acid in the oceans" - huh?

August 10, 2015 at 3:43 pm
Isn’t it interesting how sulfuric acid which will eventually be precipitated out of the atmosphere must be so much more benign than than acetic acid in the oceans. At least the “oceans are going acidic” crowd never seems to address what must have been some seriously acidic environments in the past.

And if he thinks that scientists haven't looked at past ocean acidification events, he's wrong.

References and further reading

Lori S. Glaze, Stephen Self, Anja Schmidt, Stephen J. Hunter. "Assessing eruption column height in ancient flood basalt eruptions." Earth and Planetary Science Letters, 2015; DOI: 10.1016/j.epsl.2014.07.043

NASA simulation indicates ancient flood volcanoes could have altered climate - press release from ScienceDaily.com

Columbia River Flood Basalts - article about Columbia River Flood Basalts  from Oregon State University