Chlorine, nitrogen and the legacies of Fritz Haber
His ammonia process fed the world – but he also pioneered chemical weapons
Fritz Haber was the chemist behind the first mass use of chemical weapons in the first world war, releasing chlorine gas in the trenches at Ypres. But before the war, he had been responsible for the developing the process for taking nitrogen from the air and turning into ammonia, a crucial ingredient for fertilising crops. How should we remember him, as a war criminal, or the man most responsible for feeding the world’s current population?