Not the OP, and this is probably not what they were thinking of, but from the point of view of the planet's ecosystem, eliminating the humans that keep introducing species where they don't belong (or at least drastically reducing their population) would be the most effective measure.
Not the OP, and this is probably not what they were thinking of, but from the point of view of the planet's ecosystem, eliminating the humans that keep introducing species where they don't belong (or at least drastically reducing their population) would be the most effective measure.