Concept of Carbon-related Energy to Connect Energy Consumption with CO₂ Emissions

Abstract

Reducing carbon dioxide (CO₂) emissions from energy consumption is an urgent requirement to address climate change. The difficulty for energy consumers to consciously perceive CO₂ emissions largely hinders the reduction of CO₂ emissions. The purpose of this study is to develop new indicators to help CO₂ emissions to be perceived intuitively and to show the applications of the new indicators. The main results of this study are as follows. (1) The authors introduce the new concept of CE (carbon-related energy) that shows a very strong correlation with CO2 emissions based on heating values and the element contents of fuels. The authors introduce CE-derived concepts such HE (hydrogen-related energy), RE (renewable energy), and CE ratio. (2) The CE ratio that is defined as CE per energy is the index of CO₂ emissions intensity per energy. The CE ratio that is expressed as a normalized index ranging between 0.0 and 1.0 would intuitively be perceived by energy consumers. (3) Using the modified Kaya identity that the authors derived using the CE-derived concepts, an increase and decrease in CO₂ emissions can be explained by the factors concerning CE-derived concepts and GDP. Using the CE-derived concepts, energy and CE as the indices of CO₂ emissions can be described in one unit in a table or a figure instead of separately.