Did you know that nearly 10 percent of all CO2 emissions come from the creation of cement alone? That’s more than from all aviation!

We rarely think about cement despite the fact that our society would literally collapse without it. Roads, bridges, buildings, and more all depend on this material that’s so ubiquitous we barely even notice it. In fact, concrete is by far the heaviest part of humanity’s footprint on the planet, and today all the materials we’ve built with it are heavier than the weight of all living beings on the earth.

In other words, the carbon intensity of cement production is a big deal. In this episode, we talk with Sublime Systems co-founder Leah Ellis about her effort to decarbonize cement production for which she’s already raised $50 million. 

As you’ll hear, rather than heating up limestone to hellish temperatures to make cement—the currently dominant method—Sublime harnesses the power of electro-chemistry to convert calcium-bearing rocks into cement at room temperature, thereby slashing emissions.

Already Sublime has built a $10 million pilot plant demonstrating the viability of its technology and it plans to make its commercial debut within 2023. Next step: build a full scale commercial factory that can really start making the dent in the climate crisis that Leah is seeking to make.

Discussed in this episode

• The Romans were pretty good at making cement!

• Sublime Systems raised a $40 million Series A round in 2023

• Patent applications from Sublime Systems

• CNBC on Leah’s work with Sublime Systems

More about Leah Ellis

Leah Ellis is the CEO and co-founder of Sublime Systems, a company that aims to revolutionize cement production through its breakthrough low-carbon process. With a pilot plant in Somerville, Massachusetts capable of producing 100 tons of decarbonized cement annually, Sublime recently secured a $40 million series A funding to drive growth. Leah and her co-founder, Yet-Ming Chiang, developed the technology while she was an NSERC/Banting Postdoctoral Fellow at the MIT Department of Materials Science and Engineering. Leah holds a PhD in chemistry from Dalhousie University, where she worked with Professor Jeff Dahn on lithium-ion battery optimization in partnership with 3M and Tesla. Leah was named among MIT Technology Review's 35 Innovators under 35 and is among the World Economic Forum’s Technology Pioneers.