Volcanic ash = global cooling?

[Heero]

Just thought this was pretty interesting, and wanted to pass along.

I was watching the news about Obama not being able to attend the Polish President's funeral because of the volcanic ash that's pretty well shut down the majority of the airspace over Europe, and it got me wondering about the atmospheric effects of the ash (cause I'm a nerd like that), since there seems to be a lot of it coming out of this volcano.

While a good bit of what I found was indeed from the wiki-brains, there's a bit of history to the effects on the global climate from enormous deposits like this into the atmosphere. Back in 1815 a volcano had a huge eruption, spewing enormous amounts of ash into the stratosphere, and the following year experienced what was known as the "year without a summer". Apparently a minor cooling happened (0.7-1.4 degrees Fahrenheit) however that little bit had a pretty devestating effect. The ash blocked so much energy from the sun that people could apparently look at it with the naked eye (stupid) and pick out sun spots (awesome but still stupid).

Now to be clear, I understand that this isn't something that has a long lasting effect in and of itself; but rather a more short term change in climate. However it's still wild (geekiness showing itself here) to see how climate can be effected.

If anyone's a geek like me, here's a link to the wiki article on volcanic ash:
http://en.wikipedia.org/wiki/Volcanic_ash


-Heero