THE RECORD
What changed
Haber's synthesis and Bosch's engineering led to large-scale ammonia production in 1913.
EVIDENCE
What remains
Apparatus, patents, BASF records and production statistics document scaling.
WHY IT MATTERS
Why it matters
Fertilizer supports billions of people while increasing energy use, water pollution and nitrous oxide.
OPEN QUESTION
Where interpretation begins
Population growth had many causes; ammonia fed explosives, and Haber's chemical-warfare role matters.