Will The Chilean Volcano Be Big Enough to Cool 2015?

April 24, 2015

After peeling my jaw off the floor from watching this series of stunning time lapses, first thing that came to mind.

Large volcanic eruptions can eject a enough aerosol particulates, sulfates especially, high into the atmosphere, to reflect significant amounts of sunlight, and cool the climate for a period of months, or longer.

After consulting with several experts, one early take is that it’s not the right time of year in the southern hemisphere for the particles to get entrained high enough to make a difference. More study needed.

UPDATE: Carbon Brief has a piece on this question:

Not all volcano eruptions are the same. Volcanic eruptions are rated from zero to eight on a scale of  explosivity, measured by the amount of ash and debris they produce.

Before Calbuco, the most recent significant volcano eruption was Mount Pinatubo in the Philippines in June 1991. This was rated as a six, while the first of the Calbuco eruptions has been rated as a four or five,  according to a minister of the Chilean Government.

The characteristics of the ash cloud largely determine whether an volcanic eruption influences the climate or not.

One important factor is how high it reaches in the atmosphere, Prof Richard Allan, professor of climate science at the University of Reading, tells Carbon Brief:

“If a volcanic eruption is large enough to reach the stratosphere – above 8km in polar regions and above 15km in tropical regions – the absence of weather at these altitudes means that the injected aerosol particles can stick around for a number of years, reflecting sunlight back to space and cooling the planet.”

The Pinatubo ash cloud extended 35 kilometers into the atmosphere, cooling parts of the world by up to 0.4C for two years after the eruption.

It’s not just the spectacular eruptions that can affect the climate. Recent research has suggested that even small eruptions could be contributing to slower surface temperature rise in the last 15 years or so, compared to previous decades.

Satellite images suggest the Calbuco ash cloud has reached at least 14km, Dr Anja Schmidt, a researcher in volcanic impacts and hazards at the University of Leeds, tells Carbon Brief.

Climate impacts

Another important factor in whether a volcanic eruption influences climate is the amount of sulphur dioxide contained in the dust cloud. And the quantities can be huge. The recent Bárðarbunga and Holuhraun eruption in Iceland are estimated to have produced as much sulphur dioxide as the whole of the European Union did in 2014, notes McQuaid.

Once in the stratosphere, fast-moving winds can quickly spread the ash cloud around the world, giving a local eruption a global impact.

It’s early days but previous experience suggests the Calbuco eruption won’t be producing such large amounts of sulphur, Schmidt explains:

“Based on eruptions of other Chilean volcanoes, like Chaiten or Puyehue Cordon Caulle, huge emissions of sulfur dioxide are not expected, or supported by the satellite data.”

The geographical position of Calbuco may also restrict any global impact, Schmidt says:

“Global climate impacts are also unlikely due to the southern latitude of the eruption, but if the sulphur dioxide mass emission rate were to increase this eruption may temporarily enhance the aerosol particle concentrations in the upper troposphere and lower stratosphere.”

Schmidt says right now, the priority is to ensure aviation safety by monitoring and predicting how the ash cloud disperses.

One of the early tests of climate modeling that really caught my attention in the early 90s, was when Jim Hansen built a simulated volcanic eruption into one of the curves he presented to Congress in 1988.  When Mt Pinatubo obliged and exploded in 1991, the resulting perturbation in global temps closely resembled Hansen’s graph – showing his modeling had great skill in simulating temp behavior in the actual globe.  I described this in an early Climate Denial Crock of the Week video, below.

Relevant passage at 5:55. Sorry for the annoying music, I was still new at this.

16 Responses to “Will The Chilean Volcano Be Big Enough to Cool 2015?”

  1. MorinMoss Says:

    Peter, you must have read my mind; I was wondering the same thing last night and was trying to find estimates on the amount of ejecta or comparisons to Pinatubo.

    What does the southern latitude have to do with the climatic impact? Is it because it’s shifting to winter?

    • dumboldguy Says:

      Google “images of comparative sizes of volcanic eruptions” for some good graphics. Also see:

      This volcano looks like it is small potatoes for a number of reasons.
      Some numbers—-cubic miles of magma/ash ejected:

      1/10—-Mt.. St, Helens
      240—–Yellowstone (600,000+ years ago and another eruption is overdue)

    • greenman3610 Says:

      heading into southern hemisphere winter, less insolation overall in the south, so any aerosol will not have as big an effect.

      • MorinMoss Says:

        But don’t the particles persist for some time – I’ve read that Pinatubo’s aerial rubbish was up there for a couple years – is that not right?

        • dumboldguy Says:

          Yep, the ash falls out fairly quickly but the sulfur aerosols can stay up for years, as Pinatubo’s did. The bigger the eruption, the more is ejected, and the higher it is blown—-this one doesn’t look like it’s going to have much effect.

          (And something that is not discussed much among us anti-coal types is that the sulfur dioxide released from burning coal morphs into aerosols that help to cool the earth. If we stop burning coal, yes, we will reduce CO2 emissions, but we will also remove things that contribute a bit to cooling).

          • MorinMoss Says:

            I’ve raised that very point about coal-burning on other forums from time to time.
            And that is going to be a big bite-in-the-ass when China cleans up their act.

            It’s been a couple years since they published their as-clean-as-USA emissions standards for power plants and the deadline for compliance was last fall.

            Now it remains to be seen if the enforcement has teeth but Beijing showed the big stick by not allowing ANY plants to be grandfathered.
            If you can’t clean up, then you shut down.

            If India follows suit, that massive haze known as the Atmospheric Brown Cloud could be nearly gone in under a decade – but the region would get warmer much more quickly.

            On the flip side, a small positive is that glacier melt may slow down if fewer dark particles are coal-escing on their surfaces. 😉

        • andrewfez Says:

          Tambora hit in April 1815, but the pain happened in 1816, which is called ‘The Poverty Year’ or ‘The Year Without a Summer’. The drop was 0.4 – 0.7C.

          The disruption in the UK is something i featured in the book i wrote about science denial, set in 1820-21. In my book, I criticize Laissez Faire capitalism, by exhibiting a set of farmers’ shyness, regarding mineral manure improvement of farmland: They got burned in 1816, when a set of snake-oil salesmen (quarrymen) sold them the idea they could recreate the success of ‘cold and wet’ Scottish farming, by adding random marls from their quarries, during the cold and rainy 1816 summer. The quarrymen did well; those that were desperate enough to purchase the marls went bankrupt. And in 1820, when a real scientist shows up to see what he can do to improve the land by way of liming, marling, and several other rudimentary methods of fertilization, he’s met with an unhealthy dose of skepticism, secondary to these laissez faire men’s doings, four or five years before.

          Later in the book, a Baptist preacher challenges an Anglican parson to a duel, for he comes to believe the Christian god preemptively punished their community in 1816, secondary to the latter man attempting to teach basic natural history to their community in 1820-21 (early geology and pre-Darwinian evolution). 1816 represents ‘the consequences when Christians abandon God (by accepting science)’; and I draw a parallel between modern Christian thoughts on popular tragedies (climactic or otherwise), where such are attributable to ‘taking God out of our schools’, &c.

  2. peterangelo Says:

    One Word Tambora. This Vlocano appears to be no where near large enough to have kind of impact some are theorizing. it might dampen to some very small degree we shouldn’t delude ourselves into believing it will significantly impact global climate.

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