Fritz Jakob Haber (German: [ˈfʁɪt͡s ˈhaːbɐ] ; 9 December 1868 – 29 January 1934) was a German chemist who received the Nobel Prize in Chemistry in 1918 for his invention of the Haber process, a method used in industry to synthesize ammonia from nitrogen gas and hydrogen gas. This invention is important for the large-scale synthesis of fertilizers and explosives. It is estimated that a third of annual global food production uses ammonia from the Haber–Bosch process, and that this food supports nearly half the world's population. For this work, Haber has been called one of the most important scientists and industrial chemists in human history. Haber also, along with Max Born, proposed the Born–Haber cycle as a method for evaluating the lattice energy of an ionic solid.
Haber, a known German nationalist, is also considered the "father of chemical warfare" for his years of pioneering work developing and weaponizing chlorine and other poisonous gases during World War I. He first proposed the use of the heavier-than-air chlorine gas as a weapon to break the trench deadlock during the Second Battle of Ypres. His work was later used, without his direct involvement, to develop the Zyklon B pesticide used for the killing of more than 1 million Jews in gas chambers in the greater context of the Holocaust.