The 2022 Environmental Performance Index is composed of 40 indicators measuring different aspect of environmental sustainability, including trends in greenhouse gas emissions, deforestation, waste management, air quality, etc.
Deciding how much each indicator counts towards the overall EPI score involves some subjectivity, and some have criticized the weighting scheme in the 2022 EPI.
The EPI website has a tool to modify the relative weights of environmental issue categories and policy objectives, but not the weight of individual indicators.