Question: How would you make an artificial volcano errupt?

Angus Ferraro answered on 21 Jun 2013:

Volcanoes cool the planet down because they put tiny particles high into the atmosphere which reflect some sunlight (a bit like a cloud, but much less reflective!). An artificial volcano just needs to put particles into the atmosphere.

One way we could do this is to pump them out of planes. Another way is to use a massive balloon (bigger than any balloon ever made – stadium-size) to pull a pipe about 20 kilometres up and pump the particles up through the pipe. The most ‘volcano-like’ way is to use guns to shoot things into the atmosphere.

Obviously pumping things into the atmosphere isn’t necessarily a good thing. Doing this would probably cool the planet but it might have other side effects so it might not be a good idea. I am researching these side effects.