Interestingly, the sun would kill us much sooner than that: in less than 1 billion years the sun's increased output will heat up the Earth's surface to the point of becoming unlivable.

Related to the topics of AI apocalypse and putting things off because they seem far away: I personally find it amusing to contemplate a strong AGI being developed in 2035 and wiping out humanity. Why? Because it would eliminate the Y2038 problem, retroactively vindicating all the engineers who only allocated 32 bits to timestamps. It would mean the justification of "oh, it's so far off, the world will have changed unimaginably by then", would for once turn out to be correct!