Over nearly all of Earth's history, threats have come from nature — disease, earthquakes, asteroids and so forth — but from now on, the worst dangers come from us.
Teju visu Zemes vēsturi draudi ir nākuši no dabas — slimības, zemestrīces,  asteroīdi un tā tālāk — taču šobrīd lielākās briesmas  radām mēs paši.