The Carbon Equity Index: An Integrated Geospatial Model for Prioritizing Clean Energy Infrastructure Investments

The equitable distribution of clean energy infrastructure is essential for achieving both climate justice and sustainable development goals. While existing frameworks evaluate emissions and socioeconomic vulnerability, they often do so independently, lacking a unified metric that incorporates actual investment flows to guide policy. This paper introduces the Carbon Equity Index (CEI), a novel geospatial model that quantifies inequity as a function of cumulative environmental burden, socioeconomic vulnerability, and the realized deployment of clean energy investments. Using publicly available data from the U.S. Environmental Protection Agency’s EJScreen (2024), U.S. Census Bureau TIGER/Line files (2023), and a simulated clean energy investment portfolio, we calculate tract-level CEI scores for over 85,000 census tracts across the United States. The results reveal a significantly right-skewed distribution of inequity, indicating that a minority of communities face compounded burdens. Analysis of the highest-scoring tracts identifies specific, underserved communities where substantial clean energy investment is absent despite extreme environmental and demographic need, with a notable geographic concentration in Los Angeles County, California. The CEI offers a scalable, transparent, and dynamic decision-support tool for federal, state, and local agencies to strategically target investments, operationalize policy mandates like the Justice40 Initiative, and track progress toward a more just energy transition.