a little history lesson

Earth was a fireball, then a water world, then a snowball then a swampy paradise all in the span of about 5 billion years. 

There were only single celled organisms living under water because if they were to come out of the water they would die from the CO2 emissions and other toxic fumes in the air. Once there was actually O2, the single celled organisms evolved. Then, 90% became extinct due to volcanic eruptions. Then dinosaurs came to be and were so gargantuan because they were lukewarm blooded. They too were wiped out.

All of these mishaps and obstacles to maintain life on earth only make me think of one thing:

When is it our turn to get wiped out?