This issue of Photonics Focus explores the promise of photonics technologies to help meet goals for sustainability. One story details the urgent need to apply photonics solutions that would lower the enormous power consumption of data processing centers, now reaching their limits with the advent of artificial intelligence. The issue also considers photonics solutions to the global clean-water crisis, as well as the potential for concentrating solar power to feed the electric grid, even at night, among other planet-saving applications.