I was thinking of the fox's point of view ;-) Anyway, valuable to whom? Obviously, the life of a human is more valuable to another human. The fox population is tiny and fairly static, but the human population is horrendously large and growing at an unsustainable rate. From a detached and objective point of view a human life is not worth much.
My garden has grey squirrels, foxes and the occasional badger, and I feel my life is enriched by them.
The few that do survive will be back in the stone age. Have you seen the Horizon programme on global dimming?