Until now, there was no universal, comprehensive methodology for cities around the world to measure their emissions. One of the tool's creators explains its power in the fight against climate change.
Artificial light is a growing problem that’s hurting humans and animals. What are cities doing about it?
Grand Rapids, Mich., stands as tangible evidence of what cities can do to reduce human impact on the environment. But the city’s efforts also underscore its limitations.
Water bills have increased faster than any other and show no signs of slowing down, hitting low-income Americans the hardest.