Decarbonizing concrete: No time to waste

Growing up in the rapidly urbanizing city of Mumbai, I became captivated by the potential of cement. I was amazed by how a flaky gray powder is the fuel that can—quite literally—develop nations. Only after reaching college, where I explored this material in greater depth, did I learn that cement hides a dark secret: It’s responsible for a staggering 8% of global CO2 emissions.

Upon entering the Stanford Graduate School of Business, I made it my mission to decarbonize concrete. But in my third week, I met an exceptionally knowledgeable industry expert who began our conversation with “Don’t waste your time.”

Cement is what’s known as a “hard-to-abate” sector—meaning the industry is especially difficult to lower CO2 emissions in. While each ton of cement emits a relatively low amount, the real challenge lies in the industry’s scale, economics, process, business models, and regulation:

Scale

A staggering 600 kg (1,300 lbs.) of cement is produced per person per year, and concrete (cement’s end product) is the most consumed material on the planet. Cement consumption, 90% of which is consumed in developing countries, continues to increase over time, making the emissions problem ever more urgent.

Economics

Priced at $120 per ton in the United States and as low as $30 per ton in India, cement is remarkably affordable and is a low-margin commodity. Understandably, mass customers are not willing to pay a premium for lower CO2 emissions.

Process

Cement is traditionally manufactured by taking limestone (calcium carbonate) and breaking it down with heat (usually coal) to form calcium oxide and CO2. Thus, decarbonizing cement means addressing the challenge of both lowering emissions from breaking down calcium carbonate and from burning the coal needed to generate heat.

Business models

Cement production is a local monopoly because it is uneconomic to transport over long distances. Yet only a few firms can operate on the massive scale required, creating a national oligopoly. This creates high barriers to entry for newcomers.

Regulation

Cement, used to construct houses, hospitals, and bridges, is a safety-critical material governed by stringent regulations that resist change.

For all these reasons, I was advised not to waste my time trying to decarbonize concrete. The industry, I was told, is responsible for solving its own emissions problem. To their credit, cement companies have heavily invested in lowering emissions through Type 1L Cement (cement with a 10% lower carbon footprint), carbon capture technologies, and the use of supplementary cementitious materials like LC3, fly-ash and slag. At every U.S. cement conference, lowering emissions has become a central focus of discussion.

Even so, these efforts are not enough. The Global Cement and Concrete Association has committed to producing carbon-neutral concrete by 2050. Crucially, the industry assumes meeting these targets requires significant carbon capture efforts (42% of the reduction) and efficiency and optimization improvements (42%). These assumptions are inherently biased because they incentivize investment in continued operations rather than promote radical new material innovation.

Startups and new research can play a pivotal role in pushing the boundaries of material innovation. At Stanford, I am part of a team developing a low-carbon material and am supporting Professor Tiziana Vanorio to commercialize her low-carbon cement. Through innovation we have created materials that are cost-effective, widely available, and can be readily accepted.

Some may say I am wasting my time. But I would argue the cement industry needs to stop wasting its time and actively support more innovative decarbonization efforts. Forward-thinking cement leaders and startups must partner together to commercialize and rapidly scale lower-carbon materials. If we waste more time, by 2050, we’re all doomed.

Krish Mehta is a Knight-Hennessy scholar pursuing an MS in environment and resources and an MBA at Stanford. Having witnessed the devastating impact of climate change on vulnerable communities in India, Krish is focused on lowering carbon emissions from hard-to-abate sectors.

All photos courtesy Krish Mehta.

Knight-Hennessy scholars represent a vast array of cultures, perspectives, and experiences. While we as an organization are committed to elevating their voices, the views expressed are those of the scholars, and not necessarily those of KHS.