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Company focus Jul 04, 2023

President's message: The Big Five

On December 12, 2015, 196 nations signed the Paris Agreement at the UN Climate Change Conference. The agreement went into force on November 4, 2016, and the signatory nations represent 96 percent of global greenhouse gas emissions. A country’s commitment to the Paris Agreement is documented in its nationally determined contributions (NDCs), which must be updated and resubmitted every 5 years to the United Nations Framework Convention for Climate Change. With each update, every country must improve its global warming commitments. This article focuses on the top five per-capita emitters of greenhouse gas emissions on the planet and examines NDCs.

Figure 1 shows the top five nations, or the “big five,” with the greatest per-capita emissions as of June 2021.



Although China, the United States, the European Union, Russia, and India are the top five countries with the greatest total emissions worldwide (indicated by the colored rectangles in Figure 1), the top five per-capita emitters are Saudi Arabia, Australia, the United States, Canada, and South Korea—the first five countries, left to right, in the figure.

Figure 2 shows the per-capita emissions from the big five since 2000.



Australia, Canada, and the United States have demonstrated a reasonably consistent downward trend in per-capita emissions since 2005, which is good news! The year 2005 coincides with the three countries’ “base year”—an important date each signatory to the Paris Agreement submits in their NDC. Per-capita emissions in Saudi Arabia and South Korea have trended upward since 2000 and have peaked since 2015. This correlates with South Korea’s chosen base year of 2018. Saudi Arabia’s base year is 2019. The decline in emissions in 2020 was significantly aided by the pandemic.

By the end of this decade, the big five countries have committed in their NDCs to lowering their emissions to about 50 percent of what they emitted in their base year, and all except Saudi Arabia have committed to becoming net-zero-emitting nations by no later than the middle of the century. Canada and South Korea have enacted legislation that commits to achieving net zero. The Canadian Net-Zero Emissions Accountability Act came into effect in June 20211, and in South Korea, the Carbon Neutrality Act was enacted in September 2021 2. Australia and the United States have not yet enacted legislation, preferring to let their NDCs implicitly drive toward net zero. Saudi Arabia has not committed to achieving net zero but has put forward several national green programs to significantly reduce their greenhouse gas emissions.

All 196 nations that signed the Paris Agreement are transitioning away from energy waste and burning fossil fuels. We are witnessing this trend in the per-capita emissions data now, and as the remainder of the decade unfolds, it will be interesting to see the paradigm shift the big five will undergo to achieve the low-carbon economies intended by their NDCs. For those of us with careers in the built environment, we have a critical part to play in the NDCs by delivering the solutions needed to sustainably decarbonize buildings and the construction sector.


Tom Zaban, P.Eng, LEED Green Associate