Volcanic eruptions are kind of a double-edged sword.Originally Posted by walterick
On one hand an increase in volcanic activity does tend to have a cooling effect, but that is because of the vast amount of smoke and debris that is strewn into our atmosphere and tends to get trapped up there by stratospheric inversion. As this eventually dissipates, the earth warms up. But the ozone depleting gasses emitted continue to contribute to the warming effect. That's why the ozone hole is in the southern hemisphere, because that is where the vast majority of volcanic activity occurs.
They knew all this stuff back in the 50's, as evidenced by my 1950 something geology book. So what we are seeing in terms of "global warming" is simply nature being cyclical.
Now that's not to say I don't believe that there won't be global environmental catastrophe(s) in the future. But this belongs to my religious beliefs, and since I don't wish to go off topic I'll keep it to myself unless asked.