Solving cement’s climate problem

Right now, in the U.S., it’s hard to find signs of progress in the effort to decarbonize the economy, as funding under Biden-era climate programs is revoked, frozen, clawed back, or – at most – just plain uncertain.

One topic that’s both (perhaps surprisingly) interesting and relatively encouraging is the effort to make low-carbon cement, the key ingredient in concrete. These materials cause some 8% of global carbon emissions. (Plus, amazingly, concrete is the second most consumed substance on Earth, less only than water.) Two things make cement production problematic. One, the heat necessary to make cement usually comes from fossil fuels. Two, the central process of making cement requires splitting limestone (CaCO3) into the main ingredient of cement (CaO) and the byproduct, CO2.

The challenges and obstacles to fixing this significant problem are considerable, but this is one area where the array of startup companies makes clear both human ingenuity and the social benefits of venture capitalism.

Good introductory and overview articles

• “How to decarbonize the world’s cement.” Hannah Ritchie, Substack newsletter “Sustainability by numbers.” A short, lucid explanation of the general options.
• “To decarbonize cement, the industry needs a full transformation.” Jeff St. John, Canary Media. A very thorough look at opportunities and (especially) challenges, this piece is mostly reader-friendly with lots of good links. As the pieces below suggest, Canary Media is a major source of journalism on this subject.
• “Terra CO2 says its Texas factory will cut carbon and cost from cement.” Jeff St. John, Canary Media. Though centered on one company, this piece is also quite thorough, with numerous additional examples of methods, materials, and companies working to transform this industry.
• “Reinventing the world’s favorite building material.” William Booth and Emily Wright, Washington Post. Very readable overview story about a U.K. company making cement with slag left over from steel production, again within the broader picture.

Examples of startups and various methods

• “Cement has an emissions problem. Can tech that mimics coral fix it?” Isobel Whitcomb, Canary Media. Focused on the San Jose company Fortera, this piece traces the fortunes of a venture-capital startup.
• “How this NYC factory is trapping CO2 in concrete blocks.” Maria Gallucci, Canary Media. Part of a Canary Media series on decarbonizing steel, cement, and chemicals, this article and very short video focus on the collaboration between Glenwood Mason and CarbonQuest.
• “We are closing in on zero-carbon cement.” Podcast conversation between David Roberts and Leah Ellis, CEO of Sublime Systems. Just over one hour. Also about this company (one of many startups that owe their beginnings to university research), see “How electricity could help tackle a surprising climate villain.” Casey Crownhart, MIT Technology Review.
• “Taking carbon out of the air and putting it into concrete.” Another (one-hour) podcast with David Roberts, this time with Shashank Samala (CEO of Heirloom) and Robert Niven (CEO of CarbonCure). (Roberts used to work with Canary Media but now has his own excellent podcast, Volts.)
• “Moss concrete by Respyre: An eco-friendly approach to urban construction.” Joe Verde, Happy EcoNews. This one is just for fun: a new kind of “bioreceptive” concrete is being used in the Netherlands to turn gray buildings green with moss.

What now?

• “These startups are teaming up to decarbonize cement and concrete.” Maria Gallucci, Canary Media. About the Decarbonized Cement & Concrete Alliance; you can double-click on a hexagon on their homepage to see what each of the 12 participating companies is doing. While these companies have likely benefited from Biden-era climate grants and will feel their loss, a fair number have backing from Bill Gates’ Breakthrough Ventures. It seems that their funding will be safe from the recent cuts to Gates’s many and varied climate programs. See here (NYT) or here (Geekwire).
• “States are moving forward with Buy Clean policies despite Trump reversal.” Maria Gallucci, Canary Media. About numerous coalitions among states being formed “to cut carbon emissions from building materials even as the federal government bows out.”