Random Thoughts

Four materials rank highest on the scale of necessity, forming the four pillars of modern civilization: cement, steel, plastics, and ammonia are needed in larger quantities than are other essential inputs. Ammonia deserves the top position as our most important material: its synthesis is the basis of all nitrogen fertilizers, and without their applications it would be impossible to feed, at current levels, nearly half of today's nearly 8 billion people. These four materials share three common traits: they are not readily replaceable by other materials; we will need much of them in the future; and their mass-scale production depends heavily on the combustion of fossil fuels, making them major sources of greenhouse gas emissions. Fossil fuels remain indispensable for producing all of these materials.