Anu Ramaswami, the Sanjay Swani ’87 Professor of India Studies and a professor in three other programs — the Department of Civil and Environmental Engineering (CEE), the Princeton Institute for International and Regional Studies, and the High Meadows Environmental Institute — has developed a new tool that helps city planners navigate the net-zero future and set priorities.

“About 55% of the world’s population lives in cities, and more than 90% of the world’s gross domestic product is generated in cities,” she said. “If you can figure out zero-carbon strategies at the city scale for different types of cities across the globe, there’s potential to solve global challenges with local benefits.”

The tool, called a Zero Emissions Calculator for Communities (ZECC), is a carbon dioxide emissions calculator. It helps cities reach carbon “net-zero,” sometimes called “carbon neutrality,” balancing the amount of carbon dioxide emitted with the amount absorbed from the atmosphere. Cities that emit no more greenhouse gases than are permanently removed are essential to averting the worst consequences of climate change, say experts.

Specifically, the new tool allows city planners to design a portfolio of actions that encompasses compact development, smart electric mobility, electric heating systems, mass timber construction, urban reforestation, and technologies that allow resources to circulate efficiently through the food, waste and energy sectors.