School Notes: School of the Environment
July/August 2026

Where in the world are YSE alumni?

Yale School of the Environment has launched Alumni at Work, an ongoing multimedia series documenting the real-world impact of its graduates across the globe. The series—available in both print and video—profiles alumni working at the intersection of environment, policy, and innovation.

The breadth of that work is striking. YSE alumni are behind initiatives as varied as New York City’s Summer Streets program, operations that have recycled billions of pieces of hard-to-recycle waste, and organizations connecting tens of thousands of people to the outdoors for the first time.

Alumni at Work reflects the school’s commitment to translating environmental education into measurable change. As new profiles are added, the series builds a growing portrait of a network whose reach—and impact—is genuinely global.

Follow the series at environment.yale.edu.

The volatility of Earth’s nighttime lights

For decades, scientists have used Earth’s glow from space as a measure of human progress. More light meant more development, more economic activity, and more people connected to the grid. A new study from researchers at the Yale School of Environment, the University of Connecticut, and the NASA Goddard Space Flight Center reveals a more complicated picture: the planet’s nighttime lights are not just getting brighter, they’re becoming far more volatile—reflecting an increasing fluctuation in human nighttime activity.

“Historically, economists assumed ‘more light equals more GDP.’ Our findings suggest we need to decouple light from growth in certain contexts,” said coauthor Karen Seto, the Frederick C. Hixon Professor of Geography and Urbanization Science at the Yale School of the Environment.

The research, published in Nature, analyzed more than a million daily satellite images from NASA’s Black Marble dataset between 2014 and 2022, tracking changes in artificial light across the inhabited world.