About the Tool

The PerSquareMile tool was created to identify areas where new parks and access to nature could have the greatest impact in serving the most people who currently lack access to nearby nature in California. It was developed by Jon Christensen and Zoe Frumin at the UCLA Institute of the Environment and Sustainability with GreenInfo Network.

The tool starts by laying a one-square-mile grid across the state of California. It then uses high-resolution population location data to count how many people live in each square mile of the state. It then adds parks and open space locations, demographic data, biodiversity metrics, and other environmental data to identify specific areas where investments in parks and natural areas could serve the most people in need and provide other benefits, such as restoration and conservation for other species.

The PerSquareMile tool is essentially a utilitarian tool. It enables prioritizing the greatest good for the greatest number of people most efficiently. But it can also be coupled with other data to help achieve distributional justice goals, serving populations with the greatest need. And it can help achieve conservation goals, where areas with potential for restoring and protecting habitat for other species could co-exist with appropriate access to nearby nature for people to enjoy the benefits that time spent in nature provides for human health and well-being.