Calera cement production. Photo by Jim Wilson, The New York Times.
It is commonly known that concrete is a leading contributor to global warming, and is responsible for up to 5 percent of the total global carbon footprint. The reason may be attributed to the CO2 released during the kilning process, as well as the energy embodied in the material. Given concrete’s near ubiquity in the construction industry, this negative environmental score has inspired many material researchers to look for improvements.
Silicon Valley–based Calera has received significant press lately because of their intent to reduce not only the carbon footprint of concrete, but also the footprint of coal-based energy production as well. Sound like alchemy? Scientists are certainly skeptical. While the company’s idea to capture CO2 in cement using seawater is compelling, scaleability and economic distribution remain holy grails for this process. We can hope that Calera makes early strides in the achievement of their goal, for large-scale supply will be a long-term prospect.