The footprint family: Comparison and interaction of the ecological, energy, carbon and water footprints

The year of 2012 marks the 20th anniversary since the concept of ecological footprint was introduced to the global community for the first time. Nowadays footprint studies have gained extensive debates as well as popularity. In this paper, we define the footprint family as an indicator system of selected footprints that measure some aspects of human impacts on the environment. A relatively comprehensive introduction and comparison of four key footprints is represented by listing their characteristics in different aspects. The interaction among these footprints within the footprint family is classified into three types: overlap, contradiction and complement. The description of each type is provided in detail. Limitations and uncertainties of the footprint family, and priorities for further improvement are also performed. This research makes a preliminary attempt at developing the conceptual framework for the footprint family, which allows us to examine the performance of footprints combination. The footprint family will serve as a tool for integrating footprints on human impacts assessment, and a support for environmental decision-making.