In 250M years we have probably killed ourselves 249,9M years ago anyway.
But in the unlikely scenario that we have not, we probably can fix both tectonic plate movement and/or suns energy output with 250M years of technological progress.
This has been known as a burial place for quite some time, and when they first found it they put the pieces in a barn, and then burnt it some time later.
Or we will alter the Earth's orbit so that less of the energy reaches us.