A Choice of Catastrophes
"The title of Isaac AsimovŐs non-fiction book published in 1979
"He listed some 15 possible disasters
– some certainly far in the future
– some possibly rather soon
"He sorted them into 5 classes:
–1: universe becomes uninhabitable
–2: solar system becomes uninhabitable
–3: earth becomes uninhabitable
–4: human life is destroyed
–5: civilization is destroyed