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