A decade ago, Rutgers materials scientists ​Vahit Atakan and Rik Riman set out to tackle this problem by inventing a new cement-making process that subs out some of the traditionally used limestone for a synthetic version of the mineral wollastonite. The new method--for which the company, Solidia Technologies, owns dozens of patents--requires lower temperatures and less energy, helping to reduce the carbon footprint by 70 percent. Also part of that smaller footprint: Wet Solidia hardens by absorbing CO2.

While other companies have developed alternate forms of cement before, Solidia has also demolished major obstacles to adopting it. "If I have to tell people to go buy some new equipment, a new kiln," says CEO Tom Schuler, "no one's going to adopt it." Solidia's manufacturing process can be done in existing facilities and costs about the same as--and, perhaps soon enough, less than--traditional cement-making methods. Solidia says its cement is just as strong as the standard stuff, and requires only 24 hours to set instead of the usual one to four weeks. "Concrete in New Jersey is not usually known as being very sexy, for some reason," Schuler says. "But we can make a significant dent in the global CO2 footprint."