Adding nitrogen to concrete could reduce nitrogen oxides (NOx) pollution, a major component of smog. Concrete nitrogenation could sequester 384 megatons of NOx by 2050, and the improved air quality could lead to positive downstream consequences. "It can generate economic benefits in some regions, marking a crucial first step in promoting the application of this technology," says Ning Zhang, a research assistant at the Leibniz Institute of Ecological Urban and Regional Development.