There is so much money being spent on the study of control of the weather that we really do not know how much they can control.
I remember a company two years ago that was all over the news here in Florida( they were located in Florida) claiming that they had developed a liquid product that was able to be dropped on clouds and take the cloud out. They said they asked the government to test it on hurricanes. Well now no one knows what happen to that company. They were taken out by the government.
Now is there any activate a volcano? If there is do you really think the government would tell us?
Can they activate a volcano to erupt, if they have a way to do this then they can do two things at the same time.
1. cool the earth to a point were so much ice on the North pole and South pole that there would be no warming of the Earth period/
2. They would reduce the population by 80 to 90% world wide.
3. They would not get blamed since they would say it was nature.