Effects of primary energy consumption on CO2 emissions under optimal thresholds: evidence from sixty countries over the last half century

Abbas Valadkhani, Russell Smyth, Jeremy Nguyen

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26 Citations (Scopus)


We examine how different types of primary energy consumption (i.e. oil, coal, gas, hydroelectric and other renewables) contribute to carbon dioxide emissions (CO 2 ) in the world. We allow the effects of each energy source on emissions to vary according to countries’ real income or total emission levels. To achieve this, we use a panel breaking regression with four endogenously determined break points, employing time series (1965–2016) data across 60 major pollutant countries with over 2600 observations. Our analysis distinguishes between five optimally-determined country groupings at differing stages of industrialization, technology and scale, in terms of how they generate emissions from different fossil fuels. Our findings suggest that there exist different trade-offs from switching from one primary fuel source to another at different income levels and highlight how significant fuel-specific gains can be made by using other comparable economies as benchmarks.

Original languageEnglish
Pages (from-to)680-690
Number of pages11
JournalEnergy Economics
Publication statusPublished - May 2019


  • CO2 emissions
  • Coal
  • Fossil fuel consumption
  • Gas
  • Oil
  • Renewables
  • Threshold regression

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