Hawaii Volcano Proves Sulfur Dioxide Pollution Is Really, Really Bad

This guy near a volcanic fissure in Hawaii last week is smart to wear a
gas mask. Sulfur dioxide levels are at dangerous levels near the vents.

If you want proof that sulfur dioxide pollution is bad, look no further than Hawaii

You probably noticed that in some of the amazing images coming out of Hawaii's volcano zone, the vegetation near the fissures has turned brown and dead.

Much of that actually isn't from the heat generated by the lava. A lot of vegetation is dead because of the immense amount of sulfer dioxide coming out of the vents and fissures.

If sulfur dioxide can kill plants, imagine what it can do to a human body. No wonder people are evacuated from the volcano zone. Yes, the lava is extremely dangerous. So is all that sulfur dioxide in the air.

Which is why a lot of people advocate for more pollution controls in general. Sulfur dioxide is one of the pollutants that get into the air from the burning of fossil fuels and emissions from factories. 

Obviously, sulfur dioxide concentrations in the air are far less in cities than right near the Hawaii volcano, even on the most polluted days.

But still, sulfur dioxide is harmful. It is one ingredient that forms tiny particles during periods of high pollution. These particles can get deep into peoples' lungs and cause health problems.

A badly polluted day in an average American city won't turn trees brown like the high concentrations of gases in Hawaii are doing, but the air pollution can still slow plant growth, which potentially has an impact on crops. Sulfur dioxide can also help lead to acid rain.

In super high concentrations like around the Hawaii volcano, the sulfur dioxide basically turns to sulfuric acid when you breath it in. So people exposed to the gas quickly suffer shortness of breath, and a burning sensation in the eyes and throat.

Long term effects of exposure to sulfur dioxide are not clear.

You can see in the surroundings in this video from Hawaii how the sulfur dioxide has turned the landscape brown:

Global Cooling? Bali Volcano Could (Temporarily) Reverse Global Warming

Mount Agung in Bali erupting this week. So far, the
eruptions have not been strong enough to have any
effect on global climate, but that could change. 

The Mount Agung volcano on the Indonesian island of Bali continues to barf ash as high as two and a half miles into the sky.

More than 100,000 people have been evacuated, tourists were stranded and Bali's airport was closed because all that ash in the air would wreck aircraft engines.

The wind shifted yesterday, allowing the ash to clear, flights to resume and tourists to leave. But the threat remains.

So far, the Mount Agung eruption is a rather local disaster, but it's possible it could eventually have worldwide effects. In short, it could cause global cooling. That is, if Mount Agung really blows its top.

Global warming is the big concern everywhere, of course, as increasing levels of CO2 in the atmosphere, mostly from us humans burning fossil fuels, is raising the temperature. The three years ending 2016 were the hottest for the world on record, and 2017 is going to make a run at the top three hottest.

What Mount Agung does next will determine in large part how much warmer than normal the world's temperature will be for the next few years.

So far, Mount Agung's eruptions have not been nearly big enough to have any effect on the world climate. But if it really blows, which many scientists expect, the volcano could temporarily cool the Earth's climate.

We're not talking about a new Ice Age here. Still, global temperatures would slip if Mount Agung erupted violently, which is a strong possibility. Vox quoted climate researcher Zeke Hausfather this way:

"This projection, which is based on the historical relationship between volcanic eruptions and temperature, suggests than an Agung eruption would reduce global temperatures between 0.1 and 0.2 Celcius in (the) period from 2018 to 202, with temperatures mostly recovering back to where they otherwise would be by 2023"

A worldwide temperature drop of 0.2 degrees does not sound like much, but it would be at least vaguely noticeable.

Throughout history, volcanoes have caused temporary bouts of planetary cooling. The last time this was really noticeable was in 1991, when Mount Pinatubo in the Philippines erupted, cooling the Earth by as much as 0.4 degrees Celcius in 1992 and 1993 before temperatures recovered in 1994.

This chart shows global temperature trends, rising due
to global warming. The blue dip is a projection of
the temporary cooling Mount Agung could cause
if it erupts violently. The dips in the middle of the
graph show the cooling effects of the eruptions of
El Chichon in 1982 and Pinatubo in 1991. 

That cooling was likely enough to help make a couple winters unusually  harsh in parts of the Northern Hemisphere in 1992 to 1994. (Here in Vermont, we had record cold in February, 1993 and January, 1994, but it's hard to tease out to what extent, if any, Pinatubo had on those winters.)

More notably, in 1815, Mount Tambora erupted in a much more violent fashion than Pinatubo, killing 90,000 people.

This eruption poured so much stuff into the atmosphere that the world cooled a fair amount, contributing to the 1816 "Year Without A Summer in New England, crop failures and epidemics in Europe, and more crop failures in China and Tibet.

The 1816 Year Without a Summer here in Vermont produced frost every month of the year, and snow in June, drifting to up to 20 inches deep in Danville.

Even if Mount Agung erupts terribly, we won't get another 1816. But how much the world cools from an eruption, if it does at all, depends on a few factors. The strength of the eruption is one of them. A stronger eruption would eject more ash and sulpher dioxide high into the atmosphere.

Sulfer dioxide is the stuff that would contribute most to global cooling. Sulfer dioxide particles, if ejected into the stratosphere, would reflect sunlight (much more than ash, which falls back to Earth quite quickly) and cause the world to cool.

Some volcanic eruptions pour out more sulpher dioxide than others, so how much sulpher dioxide would be in a new Mount Agung eruption would determine how much the world cools. When El Chichon erupted in Mexico in 1982, the explosion wasn't nearly as big as the one that would come from Pinatubo a decade later.

But El Chichon emitted an enormous amount of sulpher dioxide, so the world temporarily cooled after that eruption.

The vivid sky colors in Edvard Munch's
"The Scream" might have been inspired
by brilliant sunsets caused by sulpher
dioxide swept through the worldwide
atmosphere by the eruption of
Krakatoa in 1883. 

The fact that Mount Agung is near the Equator would help spread sulpher dioxide particles to both the southern and northern hemispheres which would make the volcano more efficient at cooling the Earth than volcanoes further north or south.

Volcanoes that erupt closer to the poles aren't as good at spreading their emissions worldwide, so they have less effect on climate that equatorial volcanoes.

By the way, another side effect of lots of sulpher dioxide going into the upper atmosphere, besides global cooling, is spectacular sunsets and sunrises. The particles scatter the low-angled sun light, causing brilliant reds and oranges.

The famous painting "The Scream" by Edvard Munch, with its swirling red colors in the sky, might have been inspired by the aftermath of the Indonesian Krakatoa eruption in 1883, which also temporarily cooled the planet and helped cause striking red worldwide sunsets.

Regardless of what happens with Mount Agung, global warming is not revoked. The sulpher dioxide released by the volcano will fall back to earth within a few years, but the excess carbon dioxide we continue to pump into the atmosphere will stay put.

Once the volcanic material from Mount Agung dissipates, global warming will come roaring back.

Will That Huge Chilean Volcano Cool The World? (Spoiler: Probably Not Much)

Just after the start of yesterday's Calbuco
Volcano eruption in Chile.  

I'm sure I'm not the only person who has been absolutely fascinated by the beautiful but deadly images of the Calbuco Volcano that erupted unexpectedly in Chile yesterday.

A huge plume of ash towered several miles into the clear Chilean sky, mushrooming outward as it went high in the atmosphere in kind of an End Times tableau.

I've splashed some images of the Calbuco Volcano eruption throughout this post.

The immediate worry is, of course, the people who live nearby. The eruption came as a surprise to everyone, including scientists watching the volcano, so evacuations were hasty and chaotic.

I haven't heard of any deaths yet, which is a good thing.

Huge volcanic eruptions can disrupt the global climate, though my early reading is this eruption of Calbuco won't affect things too much.

As you can tell by any photo you've seen of Calbuco, volcanoes can emit an enormous amount of ash. The ash shades local areas, but quickly falls out of the sky, so the ash itself has little if any effect on the global climate.

The ash cloud spreads out over the
erupting Calbuco Volcano in Chile.  

Volcanos can also release a large amount of sulfer dioxide, which, if the volcanic eruption is big, can get pushed into the upper atmosphere and change the climate temporarily.

If the volcanic eruption is strong enough to push sulfer dioxide all the way up into the stratosphere, the sulfer dioxide turns into sulfer aerosols.

Each molecule of these aerosols acts as a little mirror, reflecting sunlight away from the Earth and thereby cooling the climate.

There have been a number of volcanic eruptions lately, and that might have shaped a marginal, pretty much unnoticeable bit of warmth from the climate that we otherwise would have seen.

The volcano keeps erupting as the sun sets.  

Still, 2014 was the warmest on record for the entire globe, and 2015 is off to its hottest start on record, if you consider the entire Earth, so volcanic eruptions clearly haven't had a noticeable effect.

However, yesterday's Calbuco eruption was particularly large. I haven't seen any analysis from scientists on how high in the atmosphere any sulfer dioxide got, whether any got all the way up into the stratosphere, and if so, how much.

My impression is, while big, Calbuco wasn't the kind of huge eruptions that would have a significant effect on global climate. I'll be interested to see what the scientists say about this in the coming days and weeks.

We have one relatively recent example of a large volcanic eruption having a subtle but noticeable effect on the climate. Mount Pinatubo in the Philippines erupted in 1991.  It was the second largest volcanic eruption in the world for the 20th century and sent sulfer as high as 21 miles into the atmosphere.

Enough sulfer aerosols got into the stratosphere that we could all notice a haze high up in the sky, and global temperatures cooled by about a half a degree for a couple years. That doesn't sound like much, but it temporarily reversed most of the effects of human caused global warming up until that time.

And it was noticeable. The summer of 1992 was the third coolest and third wettest on record in the United States.

At, the volcano emits a bright orange glow, and
lots of lightning in the volatile ash cloud.  

The sulfer aerosols from volcanic eruptions falls out of the atmosphere after a couple of years, and global temperature trends fell back into their previous pattern by 1993 or 1994.

Volcanic eruptions have, in history, been much bigger thatn Pinatubo and had much more serious effects on the global climate.

Ancient volcanoes have caused mass global extinctions. In more modern times, a volcano called Tambora in Indonesia had enormous global impacts when it erupted in April, 1815.

According to the Economist:

".....it sent molten rock more than 40 kilometers into the sky in the most powerful eruption of the past 500 years. The umbrella of ash spread out over a million square kilometers, in its shadow day was as night. 

Billions of dust, gas, rock and ash scoured the mountain's flanks in pyroclastic flows, hitting the surrounding sea hard enough to set off deadly tsunamis; the wave that hit eastern Java, 500 kilometers away, two hours later, was still two meters high when it did so. The dying mountain's roar was heard 2,000 kilometers away."

Worse, the immense amount of sulfur aerosols sent into the stratosphere cooled the global climate for a couple years to sometimes deadly effect.

In New England and parts of the Midwest, the eruption was the main cause behind the "Year Without a Summer" in 1816. Snow drifted up to 20 inches deep in Danville, Vermont in June. Frosts hit every months of the year - including July and August - across much of New England and the upper Midwest, destroying harvests.

Harvests failed in the cold in Europe, too. Grain was in short supply in Britain. Glaciers surged down Alpine Valleys. In China thousands starved due to poor harvests and cold, said the Economist.

Again, I don't know what effect yesterday's Chilean eruption will have, if any, but it certainly will not do anything close to what Tambora did in 1815.

That volcanoes can cool the world with sulfer aerosols has gotten people thinking this could be a neat way to combat global warming.

After Mount Pinatubo erupted in 1991, a scientist named Ken Caldeira began to wonder if constantly injecting sulfer aerosols into the stratosphere would combat global warming.

He didn't think that idea would amount to much, but his studies showed that the idea would indeed work.

However, it's not something Caldeira recommends, says Grist.

He contributed to a National Academy of Sciences report that, according to Grist, "concluded that technologies to block solar radiation should not be deployed at this time; and warned, 'There is significant potential for unanticipated, unmanageable, and regrettable consequences in multiple human dimensions....including political, social, legal, economic and ethical dimensions."

So nope, we're not going to act like volcanoes and inject stuff into the atmosphere like a bunch of volcanoes.

Instead, we'll stand in awe of eruptions like Calbuco, and hope that nothing like Tambora happens again.

Here's a video, including some time lapses, of the Calbuco eruption: