When you come out, Earth may not be the same as before. The eruptions would have dumped a molten layer onto the surface, causing a huge imbalance. The planet may tip over, like Mars 3.5 billion years ago.
So, what if all the volcanoes in the world erupted at once? The answer is the long-term destruction of the entire planet and our race. Say goodbye to your McDonald’s, say goodbye to your Aldi’s, say goodbye to your regular way of life. In the aftermath of such an event, life as we know it will no longer be the same.