How to decarbonize concrete and build a better future.

Concrete manufacturing is responsible for 7% of global carbon dioxide emissions.

Yet, with growing demand for urban infrastructure, the latest data suggests its annual production could increase by more than a third by 2050.

Investment in transformative zero-carbon technologies can help decarbonize the hardest-to-abate industrial sectors, two experts explain.

Global initiatives such as the World Economic Forum's First Movers Coalition aim to harness the purchasing power of companies to ensure support.

Concrete is the most-consumed human-made resource on Earth, and the 14 billion cubic meters produced every year are projected to climb to 20 billion cubic meters by 2050, as human societies urbanize and demand for infrastructure grows. From bridges and hospitals to apartment blocks, offices and schools, concrete structures connect communities and shelter us as we work, study and sleep.

In the hands of skilful architects, concrete can create works of awe-inspiring beauty, such as Le Corbusier's Chapelle Notre Dame du Haut, Mexico City's Los Manantiales restaurant or Indonesia's Merah Putih Bridge. For climate campaigners, however, concrete is one of the ugliest materials on the planet, because its manufacture is responsible for 7 percent of global carbon dioxide emissions.

So we urgently need to find ways to decarbonize the creation of cement - concrete's key ingredient - if we are to limit global warming to 1.5 degrees Celsius. This article explores how investment in transformative, zero-carbon technologies can be ramped up, through global initiatives such as the World Economic Forum's First Movers Coalition (FMC), which aims to harness the purchasing power of companies to decarbonize the "hardest-to-abate" industrial sectors responsible for a third of the world's emissions.

Cutting clinker's carbon footprint

Concrete's popularity comes from its versatility. It can be poured and shaped into myriad forms, it's highly durable when reinforced with steel, and it's relatively cheap. The secret to its versatility lies in the binding capacity of the clinker that goes into cement. Clinker is made by roasting limestone to over 2,552 degrees Fahrenheit in kilns usually fueled by coal, natural gas or waste products from industrial fossil fuel use. The problem is, this process emits huge amounts of CO2, about 622 kilograms for every metric ton of cement produced.

Two routes to low-emissions cement show particular promise, each roughly halving clinker's carbon footprint. One is to decarbonize the production of clinker, the other is to avoid using it altogether. Both processes will be needed, but right now, the technologies are at different stages of viability and each has its own obstacles to overcome. Let's take a closer look.

Decarbonizing clinker requires roasting the limestone using alternative heat source such as electricity as a heat source instead of fossil fuels. New...