Unlocking Global Cement and Concrete Decarbonization

Concrete is all around us. From the buildings we work in to the roads we drive on, it has shaped our cities for more than 3,000 years. In fact, concrete is the second most-used substance in the world after water, and the most widely used building material. It is also responsible for around 8 percent of global CO₂ emissions.

Concrete is a mix of aggregate, like gravel, crushed rock or sand, water, and binder, typically cement. Because concrete has so many uses, there are many formulas using different aggregates, binders, and sometimes additional admixtures that do everything from accelerate hardening to change the color of the concrete. Though its use dates back to ancient times, with many of the structures still standing today, concrete formulas have evolved over the years. The formula for modern day concrete, which typically relies on carbon intensive ordinary Portland cement, was developed in the 1800s. In the face of rapid climate change, modernizing industrial sectors is essential. It’s time for the industry to evolve once again and develop low-carbon cement and concrete that will reduce pollution so we can protect the livelihood of vulnerable communities and preserve critical natural resources for our children and future generations.

The Problem with Today’s Concrete

Up to ~90 percent of the sector’s emissions occur while manufacturing cement, which hardens into concrete when mixed with water and aggregate. In the cement production process, nearly 40 percent of emissions come from the burning of fossil fuels to heat kilns to 1300-1450°C, and ~60 percent is released during the thermal decomposition of limestone to make clinker, the main ingredient of cement.

Globally, the appetite for cement is on the rise. Construction in emerging economies is expected to drive a 48 percent increase in demand in a business-as-usual scenario, from 4.2 billion to 6.2 billion tons, by 2050. This could mean even more emissions to meet needs for housing, commercial buildings, and infrastructure projects. But there are pathways to decarbonization.

A Sustainable Urban Future

RMI is accelerating the use of low-carbon cement and concrete through 4 key pillars of work: demand-creation, supply-side decarbonization roadmaps and technical support, policy and regulation, and innovation and finance—all needed to radically disrupt the pace of the transition of the sector.