Russ Steele
Ice Age Now has a interesting article on the impact of small volcano eruptions.
==============================================
An international research team has found that aerosols from relatively small volcanic eruptions can affect global temperatures.
Odin Satellite – Image credit: Swedish Space Corp
Until now it was thought that a massively energetic eruption was needed to inject aerosols all the way through the troposphere and into the stratosphere, says Adam Bourassa, from the U of S Institute of Space and Atmospheric Studies.
But when the team looked at the June 2011 eruption of the Nabro volcano in Eritrea in northeast Africa, they found that wind had carried the volcanic gas and aerosol – minute droplets of sulfuric acid – into the path of the annual Asian summer monsoon.
The monsoon lofted volcanic gas and lighter liquid droplets into the stratosphere where they were detected by the Swedish research satellite Odin.
“Once (an aerosol) reaches the stratosphere, it can persist for years, and with that kind of a sustained lifetime, it can really have a lasting effect,” says Bourassa, who led the research. “That effect is the scattering of incoming sunlight and the potential to cool the Earth’s surface.”
For example, the massive eruption of Mount Pinatubo in the Philippines in 1991 temporarily dropped temperatures by half a degree Celsius world-wide.
The research appears in the July 6 issue of the journal Science.
=================================================================
Note all eruptions on this graphic during our coldest periods.
The Next Grand Minimum 
On a tangent, Russ, but my research tells me that English summers were much wetter back in the 18th and 19thC ( and also the well known wet summers in the 14th and 15thC).
Our summer rainfall has been steadily increasing since about 1980 (in contrast to models which predict the opposite). This is a bad sign.
http://notalotofpeopleknowthat.wordpress.com/2012/07/06/english-summer-rainfall-trends/