Cement emissions in economically developing parts of the world could double by the end of this century, consulting firm Rhodium Group finds in a new report.

Cement is a key ingredient in concrete — the bland gray material that makes up our sidewalks and roads — and is responsible for 6% of global greenhouse gas emissions due to the chemical process by which it’s made.

Beginning around 2000, China blew past the rest of the world in its cement production, as the above chart shows. Cement usage in many wealthier parts of the world has likely peaked (as captured in the chart as member countries of the Organisation for Economic Co-operation and Development, or OECD). But Rhodium predicts demand for infrastructure in lower income nations will drive growth in the coming decades, which poses a problem that new technologies are just beginning to solve.

“There are not yet any mature and cost-competitive solutions for cement decarbonization,” Rhodium states. “Several options are currently under development, however, including carbon capture, hydrogen and electrical kilns, and alternative electrochemical processes.”

Startups innovating on these technologies and more are poised to receive part of an unprecedented $6 billion pot of federal support, announced by the U.S. Energy Department earlier this week, aimed at cutting emissions from the industrial sector. This sector encompasses a wide range of energy-intensive processes and materials, including cement but also steel, aluminum and more.

Read the whole report to learn more about the emissions profile of cement, the most widely used material on the planet after water, Rhodium notes.