Extinct, hardly. In fact it's difficult to conceive of an event that could make humans, the most adaptable species in the history of Earth fully extinct - it wo

Extinct, hardly. In fact it's difficult to conceive of an event that could make humans, the most adaptable species in the history of Earth fully extinct - it would have to be an incredibly violent event that wipes out pretty much all non-microbial life on the planet. Most things we worry about, like runaway climate change, do not have this capability. However, enough stress can cause civilization to collapse, as it's rather more fragile. Little things we take for granted like infrastructure, a highly specialized economy, and law and order can fall apart in the event of a nuclear war.