As part of this universe the earth is quite capable of sustaining and controlling its environs in ways that its mere mortal inhabitants could never understand. It is quite capable of causing mass extinctions of various species — no matter how large, how numerous, or how advanced. As seemingly advanced a species that we are, the earth can reduce our population in one fell swoop in a number of ways. Human intervention in this regard is not necessary.
In my opinion I would simply just enjoy the ride for as long as I can while showing the appreciation and respect for all it has provided along the way.