[Mike Darancette]

They have an effect, but it's short-term.

The eruption of the Toba Volcano some 75,000 YA came pretty near to wiping Homo Sapiens off the face of the entire earth. Blasting several thousand cubic kilometers of ash and gas into the atmosphere can have a devastating effect on the planet's inhabitants.

[cogitator]

The eruption of the Toba Volcano some 75,000 YA came pretty near to wiping Homo Sapiens off the face of the entire earth.

Yeah, I read that. I've posted this picture a couple of times:

Now this is a real crater lake: