The world's population will continue to grow, but the amount of arable land to feed that population will not.
"So people will continue to add more fertilizers to grow more crops in the same areas," says Jonas Baltrusaitis, an associate professor of chemical and biomolecular engineering in Lehigh University's P.C. Rossin College of Engineering and Applied Science, and a recipient of the 2020 ACS Sustainable Chemistry & Engineering Lectureship Award. "You can't grow crops without fertilizer. It's just not happening."
While a boon to harvests, fertilizers exact a toll on the environment. Their production alone is extremely energy intensive and a significant source of greenhouse gases, and when nutrients like nitrogen and phosphorus aren't fully taken up by plants, they can leach into groundwater and wash into waterways. Excess nutrients can cause eutrophication of water bodies where algal blooms deprive the ecosystem of oxygen, killing wildlife and producing toxins that can harm humans.