Volcanos can have a major impact on our weather and short term climate. A massive explosion like the one at Mount Pinatubo in 1991 can result in a year or two of colder temperatures worldwide (about 1 degree colder for the 2 years following). The biggest explosion in the last 200 years occured in Indonesia at Mt Tambora which resulted in “The Year Without a Summer” with summer time frosts and snow in New England.
The Eyjafjallajokull volcano in Iceland had a severe explosion in the last 48 hours (it has been active for the last month). It sent an ash cloud across the North Atlantic toward northern Europe as you can see in the satellite photo from NASA above. Airports across Europe have been closed because of this ash and scientists are worried that this explosion may trigger an even larger explosion that could have worldwide consequences.
Volcanos can shoot a massive amount of “junk” into the stratosphere which can alter the earth’s climate. Dust and ash particles can block out the sun and result in cooler temperatures but more worrisome is sulfur that can get ejected into the stratosphere. Sulfur reacts with water vapor and forms sulfuric acid which acts as a haze and can block sunlight and result in much cooler temperatures worldwide.
Of everything that a volcano emits the sulfur is the most worrisome worldwide because once it’s in the stratosphere it takes a very long time to settle and leave the atmosphere (years). Brilliant sunsets can result from a sulfuric haze in the stratosphere with sharply colder temperatures and massive agricultural problems.
The Eyjafjallajokull volcano so far is relatively minor compared to massive explosions like Pinatubo or Tambora. Here are some things to watch for…
- Eyjafjallajokull’s ash cloud is only at about 30,000 feet. High enough to impact commercial airline flights but most of the plume is below the tropopause (where the stratosphere begins) which is where worldwide impacts would begin. If the ash cloud begins to reach well into the stratosphere (say about 50,000 feet) then it would be more concerning.
- The eruption is currently a 3 on the volcanic explosivity index. A much larger explosion like a 5 (Mt. St. Helens) would be needed to impact the earth’s climate in a meaningful way. Pinatubo was a 6 (with a significant impact on climate). And Mt. Tambora was a 7 or “super-colossal” which happens once every few thousand years and had a devastating impact.
We’ll see what happens in the coming days but this is something to watch!