One chemical process feeds nearly half the people on Earth
Before the 20th century, farms were limited by how much nitrogen fertiliser the soil and manure could supply. Fritz Haber worked out how to pull nitrogen straight from the air and fix it into ammonia; Carl Bosch scaled it into industry. The Haber-Bosch process now supplies the nitrogen fertiliser behind roughly half of global food production — and decades earlier, Haber also pioneered chemical weapons in WWI.