How the World Really Works: The Science Behind How We Got Here and Where We're Going

by Vaclav Smil

Of the four substances (and despite my dislike of rankings!), it is ammonia that deserves the top position as our most important material. As explained in the previous chapter, without its use as the dominant nitrogen fertilizer (directly or as feedstock for the synthesis of other nitrogenous compounds), it would be impossible to feed at least 40 percent and up to 50 percent of today’s nearly 8 billion people. Simply restated: in 2020, nearly 4 billion people would not have been alive without synthetic ammonia. No comparable existential constraints apply to plastics or steel, nor to the cement that is required to make concrete (nor, as already noted, to silicon).