Often Nature can stop the toppling dominoes and adjust to the changes. Sometimes it cannot, and failures result, like extinctions. Of course, Nature doesn't recognize failures or successes. If dodo birds or humans go extinct, it matters not at the Big Picture level, as extinction is a fundamental part of the mechanism of Nature. But on the level of the human activity that we know and enjoy, it matters a great deal. It is practically all that matters.
We do have to stop poisoning our food and water.
