This post is a primer on the human drivers of carbon dioxide emissions, care of Our World in Data*:

What drives, and ultimately determines levels of CO2 emissions – whether at global; regional; national or local levels?

Total CO2 emissions are driven by four fundamental factors, outlined in the well-known equation: the ‘Kaya Identity‘. [Note: “total” emissions are from all sources of human economic activity, including electric power, transportation, industry, residential and commercial, and agriculture.] Total emissions, in the simplest description, are determined by:

  • Population: number of people

  • Per capita impact: average emissions per person

Per capita emissions are determined by:

  • Income: GDP per capita – richer people tend to emit more CO2

  • Technology: how much CO2 is emitted per dollar spent

‘Technology’ is determined by two factors:

  • Energy intensity: the amount of energy consumed per unit of GDP [energy/GDP]

  • Carbon intensity: the amount of CO2 emitted per unit of energy [CO2/Energy]

Total emissions are driven by the equation:

Emissions = Population x GDP x Energy Intensity x Carbon Intensity  

[Which is the same as] 

Emissions = Population x GDP x Energy/GDP x CO2/Energy 

Ways to reduce energy intensity: improve energy efficiency, switch to less energy intensive industries.

Ways to reduce carbon intensity: switch to renewable energy, switch to nuclear energy, substitute gas for coal, capture and store CO2 (CCS). 

Emissions tend to rise as we get richer because we gain access to, and increase our consumption of, electricity, heating, transport and other goods that require energy inputs. Many countries grow economically through a transition towards industry, manufacturing, and construction – activities that require large energy inputs.

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* Except where bracketed, the text consists of excerpts from Emissions drivers by Hannah Ritchie and Max Roser/Our World in Data https://ourworldindata.org/emissions-drivers Accessed on November 27, 2022. The original article contains much more information - check it out.

Soon: Comparison of CO2 emissions and trends across world regions in three charts and a table (data from the Working Group III Contribution to the IPCC Sixth Assessment Report (AR6), 2022.

Reference:

Hannah Ritchie, Max Roser and Pablo Rosado (2020) - "CO₂ and Greenhouse Gas Emissions". Published online at OurWorldInData.org. Retrieved from: https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions  [Online Resource]