The Kaya Identity

Posted in: Comment, Talks and Presentations

One of the issues that Michael Finus discussed last Tuesday night in his I-SEE seminar was the Kaya Identity, which is an equation relating to human impact on climate.  I had not come across it before – such a sheltered life!

The idea is that total emission levels can be set out as the product of four inputs: population, GDP per capita, energy intensity (per unit of GDP), and carbon intensity (emissions per unit of energy).  It's a version of the I = PAT equation (which I had heard of).

It can be written:   F = x  G/P  x  E/ x  F/E   where:

  • F is CO2 emissions
  • P is population
  • G is GDP, and
  • E is energy consumption

and where

  • G/P is a measure of affluence
  • E/G is energy intensity, and
  • F/E is carbon intensity

It can apply to nations and globally, and I wrote about carbon intensity last October.  This was one of the less gloomy parts of the talk.

Posted in: Comment, Talks and Presentations


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