Part 1 of 5 · freeIntroduction
The Earth has already been through five great mass extinctions, set off by asteroids or giant volcanic eruptions. A sixth is under way now, but for the first time it has no natural cause.
Species are disappearing 100 to 1,000 times faster than the natural rate, and the culprit is a single species: ours. This course explains the scale of the problem, its causes, and why it concerns us directly.
The rest is in the Sophia app.The remaining parts, the open-book quiz and the full glossary. Free to start; Premium unlocks everything.
- 2A collapse measured, figure by figure
- 3Five causes, one single origin
- 4Why nature is not free
- 5Limits not to cross, and a chance to bounce back
Open-book quiz9 questions whose answers are in the text.
Glossary10 terms explained in a tap.
30 languagesThe same course, from French to Japanese.
