irreversibility

/ˌɪrɪˌvɜːrsəˈbɪləti/
noun
  1. The quality or state of being impossible to reverse or change back.
    • The irreversibility of the chemical reaction meant the mixture could not be separated.
    • The doctor explained the irreversibility of the damage to the patient's eyesight.
    • Many people worry about the irreversibility of climate change effects.