In 2010, Bill Gates spoke at the TED Conference about reducing the world’s Carbon Dioxide emissions and innovation in energy technologies.


According to this equation, carbon dioxide (from our energy supplies) is a function of four things – people, services, efficiency, and CO2 emissions per unit of energy.

  • People (P) refers to the number of people living on the planet, with a magnitude of about 7 billion today and an expected value closer to 10 billion by 2050.
  • Services (S) refers to all of the services that we use, including things like the food that we eat, clothing that we wear, electronics, heating, transportation, etc.
  • Efficiency (E) refers to the energy used for each service. This number has actually been dropping over time, though it is nowhere near zero (and probably can’t be)
  • CO2 per unit of energy (CO2) refers to the amount of carbon dioxide that is released into the environment for each unit of energy that is demanded to provide the services that the world’s population uses.