Re: Ban flights altogether.
They're not in the chemical sweet spot.
Basically, it works like this: An open system under a flow of energy moves toward more-complex states. Such a system won't discriminate: it will move into states based on the amount of energy those states bind and dissipate, and the probability of those states existing under the current conditions. If the current conditions have too much heat or pressure to allow complex organic molecules to form (or remain for long after forming), then you won't get complex organic molecules. If conditions do permit complex organic molecules, then given energy and time it's highly probable - approaching certain - that they will.
In effect the system will do a random walk through its state space, and that means it tends to stay in spaces that are more probable (are larger regions of the state space). For Earth, under current solar conditions, the spaces with life are overwhelmingly probable.
Until the sun heats up enough to make complex organic molecules infeasible on the Earth's surface, there will very likely be some life here.