How Slightly Better Concrete Could Save the Planet

A few days before Christmas in 1824, Joseph Aspdin appeared before the King of England clutching a piece of paper. Beneath the title “Artificial Stone” was a one-paragraph recipe, peppered with technical terms like “argillacious” and “calcined.” Neither King George IV nor Aspdin—a bricklayer applying for a patent—could have known that this little paragraph was the foundation of the modern city. It contained the formula for Portland cement.

Aspdin's innovation, named after high-quality limestone from the Isle of Portland in England, is one of the great triumphs of modern engineering. It was simpler and hardened more quickly than Roman cement, and helped us build bigger and better bridges, skyscrapers, and factories. Unfortunately, it's also one of the greatest polluters of our time. That’s because when cement is mixed with sand and water, the result is the most-consumed material in the world—concrete.