Air traffic in Europe has been greatly affected by the ash cloud spewed by the Icelandic volcano Eyjafjallajökull. This may well have desastrous effects on the European economy, namely the airlines, which are already suffering from the recession.
But in history volcanoes have had greater impact than that. One, Icelandic, too, reinforced the “little ice age“, that was one major contributing factor to the French Revolution.
The Laki volcanic fissure in southern Iceland erupted over an eight-month period from 8 June 1783 to February 1784, spewing lava and poisonous gases that devastated the island’s agriculture, killing much of the livestock. It is estimated that perhaps a quarter of Iceland’s population died through the ensuing famine. (read more)
We all remember the Pinatubo. It effected an average cooling of the atmosphere of about 0,5°C. And we were treated to fabulous sunsets for months. The 1980’s eruptions of Mount St. Helens and El Chichon added to the knowledge what constitutes the cooling effect of volcanic eruptions.
It was thought for many years that the greatest volcanic contribution of the haze effect was from the suspended ash particles in the upper atmosphere that would block out solar radiation. However, these ideas changed in the 1982 after the eruption of the Mexican volcano, El Chichon. Although the 1980 eruption of Mt. St. Helens lowered global temperatures by 0.1OC, the much smaller eruption of El Chichon lowered global temperatures three to five times as much. Although the Mt. St. Helens blast emitted a greater amount of ash in the stratosphere, the El Chichon eruption emitted a much greater volume of sulfur-rich gases (40x more). It appears that the volume of pyroclastic debris emitted during a blast is not the best criteria to measure its effects on the atmosphere. The amount of sulfur-rich gases appears to be more important. Sulfur combines with water vapor in the stratosphere to form dense clouds of tiny sulfuric acid droplets. These droplets take several years to settle out and they are capable to decreasing the troposphere temperatures because they absorb solar radiation and scatter it back to space.(read more)
While checking the web for this information, I found not a single scientific discussion that uses the insight into volcanic impact on the earths climate to explain away the fact that what we call global climate change is indeed man made. Moreover, they all agreed that the greenhouse gases emitted during the modern age through man made machinery, outweigh those of volcanic activity in the same timeframe. The Pinatubo and El Chichon have even given us some respite. Maybe the volcano with the unutterable name will help us, too. If only by keeping the fuel blasting jets on the ground for a little while.