30-40% of the world’s population would not be alive without their invention.

"Humankind is largely fed by food grown with synthetic chemical fertilizer. Because synthetic fertilizer requires a plentiful supply of nitrogen, inventing a process to fix it in ammonia was daunting. Attempts were made for over 100 years. Then in 1909 Fritz Haber, a German chemist, solved the problem in principal. In 1910, Carl Bosch, pioneering new engineering methods, commercialized the process. Known as the Haber-Bosch Process, it is now responsible for growing about half of the world’s food. It was one of the greatest inventions of the 20th century. Without it, 30-40% of the world’s population would not be alive."

Science Heros

Unfortunately, it's what they did AFTER this invention that is controversial. They participated in chemical warfare development which killed over 1.3 million people in WWI. Compare that to almost 3 billion lives saved with the fertilizer.