Spiegel Sees Potential Climatic Cooling From Iceland Volcanic As Its SO2 Emissions Reach “Historic Dimensions”

Volcanic activity in Iceland has risen dramatically over the past few weeks.

Yet, thankfully, the big eruption many feared never materialized and signs show that the pressure has been subsiding. Good news, many among us may think.

Bárðarbunga_Volcano,_September_4_2014_Peter Hartree

Bárðarbunga Volcano, September 4, 2014. Picture taken by Peter Hartree , CC BY-SA 2.0.

Yet science journalist and geologist Axel Bojanowski at Spiegel warns that there’s still enough to worry about. According to Bojanowski concentrations of sulfur dioxide (SO2) have “never been higher since measurements began in the 1970s“. The amount of SO2 emitted by the recent volcanic activity is surpassed only by the “largest of eruptions”.

What’s more, Bojanowski adds:

Seldom does so much sulfur gas get into the air. It could even cool the climate.”

Photo number 12 of Spiegel’s spectacular photo series here is a NASA computer model simulation depicting the spread of the sulfur dioxide cloud over Europe. The growing concentration of sulfur dioxide is a reason for “more concern”, Spiegel reports. High concentrations of sulfur dioxide in the air are corrosive and pose a threat to human health. Bojanowski writes:

Gradually it is posing an additional threat: to the climate. The emitted amounts of gas have already reached historic dimensions, reports the country’s environmental authority, the Icelandic Environmental Agency. Daily up to 60,000 tonnes of SO2 are released from the lava chasm.”

Bárdarbunga has already emitted approximately two million tonnes of SO2. Only the largest eruptions surpass this amount.”

Bojanowski adds that although the SO2 haze in the atmosphere is not visible to the naked eye, it is seen by NASA satellite, and it extends over parts of Europe. SO2 is an effective sunblock that acts to cool the atmosphere. Spiegel also describes the Laki eruption of 1783 and 1784, which led to a marked cooling and European crop failures.

According to Spiegel, Bárdarbunga eruption and gas emission is nowhere near on the same scale as Laki, which spewed 122 million tons of SO2 into the atmosphere. But Spiegel compares Bárdarbunga’s 2 million tons of SO2 to other major 20th century volcanic eruptions: El Chichon (7 million), which was enough to cause cooling globally. Pinatubo spewed 20 million tons and cooled the planet by 0.5°C for two years.

Though Bárdarbunga’s SO2 so far has not been shot up into the stratosphere, Spiegel warns that “two factors could make the volcano’s impact detectable: At high latitudes such as those of Iceland, the stratosphere is several kilometers lower than in the tropics, thus allowing the gas to reach it more quickly. Also chasm eruptions such as those at Bárdarbunga produce hot air upward currents over the volcano, which can carry the gases up to the stratosphere.”

Note that the SO2 gas has been carried in the air over to the European continent. Though Bárdarbunga’s SO2 may not have any real impact on cooling the planet, it certainly will not help to warm it either.


10 responses to “Spiegel Sees Potential Climatic Cooling From Iceland Volcanic As Its SO2 Emissions Reach “Historic Dimensions””

  1. DirkH

    No worries. We are protected by a warming shield of CO2.

  2. Ed Caryl

    The plug in the caldera is still dropping at a constant 1 meter every 3 days. The plug catches on the volcanic throat about once a day, resulting in a 5+ earthquake when it releases. This piston action is what is forcing lava out of the fissure to the north. If the magma chamber is a couple of kilometers deep, this could go in for years. If sufficient heat escapes around the plug to melt a quantity of the ice in the caldera, and the water gets past the plug, we could be looking at one huge cannon. Watch here for warning:

  3. Hans Erren
  4. D o u g  C o t t o n 

    To all readers:

    Most people don’t understand convection and why it can just as easily go downwards in a planet’s troposphere as upwards. Disregarding radiation for the moment, an ideal non-radiating gas (say 80% pure nitrogen and 20% pure oxygen) in calm conditions (or even in a tall, sealed and perfectly insulated cylinder) tends towards the state of thermodynamic equilibrium, as the Second Law of Thermodynamics dictates it must do, increasing entropy until a maximum entropy state is attained. Such a state can have no unbalanced energy potentials, this being obvious because if it did then entropy could still increase as work could be done.

    Now, that is why we observe a density gradient in a vertical cylinder in a gravitational field. Gravity acts on molecules in flight between collisions. So-called hydrostatic equilibrium is exactly the same as thermodynamic equilibrium. You can’t have any equilibrium until you have maximum entropy within the constraints of the isolated system, of course.

    The density gradient forms because more molecules are needed at the base of the column than at the top in order to maintain mechanical equilibrium. This is because molecules going downwards gain kinetic energy, just as does a stone when falling. But temperature is proportional to the mean kinetic energy of the molecules, and for there to be no unbalanced energy potentials, the additional gravitational potential energy per molecule at the top must be offset by an equal reduction in kinetic energy. Hence the same process whereby gravity forms a density gradient also forms a temperature gradient which we derive simply by equating PE lost with KE gained: M.g.dH = M.Cp.dT so that dT/dH=g/Cp.
    as explained in an earlier comment above.

    Now, because the sloping thermal plane is really the state of thermodynamic equilibrium it acts like the level surface of a lake when new rain (thermal energy absorbed) occurs in some region of the lake (troposphere) and that new water (thermal energy) spreads out in all accessible directions away from the source of new water or thermal energy. This is simply because the extra kinetic energy in the warmed molecules causes net movement away from the source as these molecules collide with adjacent ones. But remember, it occurs in all accessible directions, so it can mean that thermal energy moves downwards to warmer regions provided that all it is doing is bringing about a new state of thermodynamic equilibrium after the previous state was disturbed.

    When there is such a disturbance to the state of thermodynamic equilibrium due to the addition of new thermal energy, then, we observe convection away from that source. So if the Earth’s surface is warmed one sunny morning in a particular region, the convection appears to go only upwards into the air. But it also goes downwards in the oceans and energy also goes downwards by conduction into the surface, so the outer layer of rocks gets warmed for example. But if air is warmed by the Sun in the upper troposphere there can be downwards heat transfer, even through the clouds and on down to the surface, which can thus get warmed even when there is total cloud cover.

    The temperature at the base of a planet’s troposphere is determined primarily by radiating temperature and the gravitationally induced temperature gradient. Radiating molecules have a temperature-levelling effect and thus reduce the temperature gradient a little. The resulting temperature at the base of the troposphere supports the surface temperature by slowing or stopping the cooling n the early pre-dawn hours.

  5. John F. Hultquist

    Note the concern by the writer regarding the Stratosphere.
    SO2 that does not make it to great height will not stay long in the atmosphere. Insofar as the growing season is over for much of the Northern Hemisphere there will be little or no effect on the 2015 growing season. The amount, so far, in the Stratosphere will be spread widely by next spring, so unless there is a massive ejection there is nothing to be concerned about.
    Consider this article as MSM bloviation.

    1. DirkH

      Hey, it’s by Bojanovski (a geologist). He’s head and shoulders above the rest of the MSM (and anyone else at Der Spiegel). He clearly says that IF the SO2 makes it to the stratosphere there could be a problem. His article is as good as anything Anthony Watts could have written.

  6. Hans Erren

    A second argument why the current SO2 emission is Iceland doesn’t cause cooling is the fact that current volcanic activity is not explosive. The SO2 stays low, is extremely hygroscopic and therefore gets washed out by abundant rain in the area.
    Only a plinian eruption that injects SO2 in the tropopause causes cooling, because the tropopause is very dry SO2 can linger there for weeks.

    Lets wait if Bardarbunga explodes.

  7. mwhite

    “it extends over parts of Europe. SO2”

    Just as well Iceland didn’t join the EU, they’d fail their SO2 emmission targets.

  8. Walt Allensworth

    Can someone please resolve the title of this piece with the summary? They appear to be polar opposites.

    To wit:

    “Spiegel Sees Potential Climatic Cooling From Iceland Volcanic As Its SO2 Emissions Reach “Historic Dimensions””

    with the last sentence of this piece:

    “Though Bárdarbunga’s SO2 may not have any real impact on cooling the planet, it certainly will not help to warm it either.”

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