Monday, April 16, 2012

Blast from the past.

1982 to be exact.  In catastrophic blasts between March 28 and April 4 the El Chichon volcano in southeastern Mexico left 1,900 people dead and destroyed millions of dollars of crops.  Not the first time a volcano has rumbled awake and smacked humans up-side their heads.  Not the first time a volcano has done something else as well - affected the climate.  As much as 10 million tons of sulphur dioxide were blasted into the atmosphere.  The ash circled the globe quickly, dropping global temperatures as much as a degree F. Temperatures in the stratosphere dropped and remained at lower than average levels for 7 years after the eruption.  Fortunately for various living things, especially third world farmers, the greatest weather affects were ameliorated by the development of a powerful El Nino within weeks of the eruption.

Since the earth really doesn't care about environmentalists, it has been changing its own weather for millions of years without any contribution from humans.  Volcanoes are a prime example of that:
 "The sun was dark and its darkness lasted for eighteen months; each day it shone for about four hours; and still this light was only a feeble shadow; the fruits did not ripen and the wine tasted like sour grapes."  Michael the Syrian, 536 A.D.
"During this year a most dread portent took place. For the sun gave forth its light without brightness. and it seemed exceedingly like the sun in eclipse, for the beams it shed were not clear.  Procopius of Caesarea, 536 A.D.
Documents for the period of 535 - 536 A.D. speak of the sun being obscured by a "dry fog", summer frosts, widespread crop failures in Europe, drought and famine in China.   Tree rings reflect poor growth, and ice cores from Greenland and Antarctica contain highly elevated levels of sulfuric acid dust.  A single massive eruptive event, and the climate was drastically affected.

1816 was "The Year Without a Summer", the "Poverty Year", and "Eighteen Hundred and Froze to Death", created by the eruption of Mt. Tambora in Indonesia in 1815.  Killing frosts and snow storms in May and June in Eastern Canada and New England caused wide-spread crop failures, and Pennsylvania lakes and rivers were still iced in July and August.  Populations plummeted, with farm loss forcing the first major migration to the American mid-west from the north-east.  Artist J.M.W. Turner captured the atmospheric affects in his paintings:

And incessant rainfall during a nasty summer trapped a vacationing group inside during their Swiss holiday, leading to a contest to write the scariest story.  The winner, by a young Mary Shelley, was "Frankenstein, or the Modern Prometheus".

At least 6 volcanic eruptions are known to have caused summer anomalies in the last 2,000 years:

Kuwae - 1452
Huaynaputine - 1600
Krakatoa - 1883
Novarupta - 1912
Pinatubo - 1991

In reality, these were small eruptions compared to others that predated written history.  Roughly 75,000 years ago, the Toba Caldera in Sumatra erupted with a force 3500 times greater than that of Tambora.  An eruption of that magnitude can cool the globe 5 to 9 degrees F for years.  The sulphur aerosol is more than the atmosphere can absorb.  An earth that was already in a cooling cycle can be pushed into an Ice Age, or, at minimum, a long cold cycle, devastating for agriculture. 

It wasn't the first time Toba changed the climate.  788,000 years ago a Toba eruption coincided with the advent of a warm period.  And a Toba-level eruption would create major temperature anomalies today:

Volcanoes capable of these sorts of eruptions are very much still around and rumbling - Yellowstone National Park sits in the caldera of a still active mega-volcano.  Thousands of years are but a blink in the history of the earth.   And all "The sky is falling!" scurrying around of the "We must stop global climate change!" folks will not and never will matter a whit in the face of the processes that truly affect our climate.


  1. The biggest effect man has on the question of "climate change" is our ability to measure ever smaller quantities. "It" wasn't a danger if it couldn't be measured. I don't believe the ozone hole was a danger until it was discovered (did it go away? I guess people exhaling CO2 and cows emitting methane became more important)

    A mere whiff of tobacco is enough to send alarms regarding the health risks of 2nd-hand smoke in parts per billion.

    One good volcano upsets all the particulate mandates the politicians can come up with.

    I generally make it a point to not talk about work on-line (losing so many good posts too...) but some of the numbers that get bandied around come about from "scientists" spending too much time plotting pretty color graphs with computer simulations


  2. @quizikle - The "hole" varies. But it's not considered newsworthy anymore so nobody is upset. Well, maybe Al Gore is.

    I think the problem is (other than unthinking emotionalism) that humans think things must remain the same as they have known them. Rotsa ruck - nothing does.

    I don't work with climate, weather, or any other related fields. Just have a degree in geology and a love of history.

  3. I'm just going to tatoo the link to this post on my right hand. Next time I get in a "discussion" aboot globalwarmingclimatechangeclimatedisruption, I'm just going to say, talk to the hand.
    The "ozone hole" was purportedly caused by CFC's. So, the freon that worked so well, R22 was phased out. How a gas that is heavier than air rises to the stratosphere to cause a hole in the ozone was of no consequence. My mind is made up! Don't confuse me with your Facts!
    When Mount Pinatubo erupted I heard a quote on the news that it put more pollution into the atmosphere than mankind had done up to that point since the beginning of the industrial revolution.
    So, I just have to wonder what the next man made crisis will be to scare the masses into a global tax and one world government.
    Epic post PH. I may just have to retire my Global Worming label.

  4. @k59 - Thanks. Ask folks if they like Montreal, New York, Boston...all of which were buried under a mile thick ice shield a few thousand years ago. What allows them to exist? Global warming. One of many cycles of ice age that are pushed back by temperature rises that eventually cycle back to cold.