We live in a changing world, but that shouldn't mean we abandon the concept of equilibrium.
Coulson T.
Ecological systems are no longer at equilibrium, but over much of the history of the Earth, the natural world has been in stationary states, that are punctuated by periods of transience. Just because we have knocked our planet away from a stable state, doesn't mean we have to abandon the concept of equilibrium when we strive to understand the dynamics of the natural world.