Companies Cut Concrete's Heavy Carbon Footprint

It's literally the foundation of modern life.

A slab of concrete underlies nearly every permanent structure on Earth. Concrete blocks are a basic unit of construction worldwide, with 1 trillion being manufactured yearly by 2027.  But concrete, the most abundant human-made material in the world, is also one of the largest sources of planet-warming carbon dioxide. Concrete manufacturing is responsible for between 4%  and 8%  of the world's carbon dioxide emissions, ranking third after fossil fuel burning and deforestation. And demand for the ubiquitous building material is expected to grow significantly to accommodate a growing population. By one estimate, building floor space will double by 2060,  adding the equivalent of the city of Paris every week.