A Critical Review of the Definition and Estimation of Carbon Efficiency

Abstract

The concept of carbon efficiency is closely related to energy efficiency but embraces a broader range of carbon emission sources. Many studies have covered carbon efficiency, investigating the climate crisis, economic growth, and a sustainable future; however, it is hard to agree that there is a consensus on the definition of carbon efficiency. To fill this gap, we reviewed the literature on carbon efficiency, especially the empirical studies that quantitatively measured carbon efficiency. As a result, we have categorized the articles into three groups based on defined criteria of carbon efficiency. We have also classified the methodology to measure carbon efficiency and to discuss misleading definitions in the empirical studies. Lastly, we suggest a desirable direction to define and measure carbon efficiency along with discussion points. Carbon efficiency is different from energy efficiency and our review will help build the carbon efficiency concept in a proper direction.