Kaya Identity Calculator

million
$
toe/$
t/toe
Ecology

The Kaya Identity Calculator estimates total CO₂ emissions as the product of population, GDP per person, energy intensity of GDP, and carbon intensity of energy. Enter the four factors.

Formula

CO₂ = Population × (GDP/Person) × (Energy/GDP) × (CO₂/Energy)
  • Each factor is a lever for reducing emissions — efficiency, decarbonisation, and so on.
  • toe = tonnes of oil equivalent, a common energy unit.

220M people, $1500 GDP/person

Inputs
  • Population: 220 million
  • GDP per Person: 1500 $
  • Energy per $ GDP: 0.005 toe/$
  • CO₂ per Energy Unit: 2.5 t/toe

220M × 1500 × 0.005 × 2.5 ≈ 4.1 billion tonnes of CO₂.

Frequently asked questions

What is the Kaya identity?
A formula expressing CO₂ emissions as the product of population, wealth, energy intensity, and carbon intensity.