The Kaya Identity

Developed by Yoichi Kaya, an engineer at Tokyo University, and a team of carbon experts, the Kaya Identity is an equation for computing the total carbon dioxide (CO2) emissions caused by humans or a specific country. The formula determines the total CO2 emissions by calculating the product of population, GDP per capita, energy use per unit of GDP, and carbon emissions per unit of energy consumed:

Carbon Dioxide Emissions = population* per capita GDP * energy intensity * carbon intensity

The Kaya identity sets the foundation for the development of future emissions scenarios in the Intergovernmental Panel on Climate Change’s Special Report on Emissions Scenarios.