Energy Excursions

U.S. CO2 Emissions

Let’s use the numbers you retrieved from the graph of Carbon Dioxide Emissions on the previous page. You determined the emissions numbers for China, India, United States, and Indonesia—the four most populous countries in the world. As countries industrialize, they tend to use more energy per capita, and currently that means those same countries emit more CO2 per capita. The most industrialized country in the world is the United States.

Let’s use 329,000,000 for the population of the United States in 2019. You already determined from the graph on the previous page that the total CO2 emissions for the country in 2019 was 4,965 Mt.

Calculate the CO2 emissions per capita (t/person) for the United States.

7.5 t/person


13.6 t/person


15.1 t/person


30.3 t/person


Let’s do a comparison by considering a table as shown below. You’ve already done some of the work to create the table:

  • The four countries and their populations in 2019 are given in the first two columns.
  • You determined each country’s total CO2 emissions for the third column on the previous page.
  • By doing the same calculation you did for the United States above, we have determined the per capita CO2 emissions for China, India, United States, and Indonesia and entered those numbers in the fourth column.
  • For the fifth column let’s do a comparison…

What if China, India, and Indonesia wanted to continue on their path of industrialization to the point that they used energy at the same per capita rate as the United States?

That increased use in energy would also increase their per capita CO2 emissions. In the fifth column we project the total CO2 emissions for China, India, and Indonesia as if they used energy (and produced emissions) at the same per capita rate as in the United States (the number you calculated above). The calculation is straightforward: multiply the country’s population by the United States’ per capita CO2 emissions rate. Consider these numbers in the table below.

CountryPopulationTotal CO2 Emissions
(million tonnes)
CO2 Emissions per Capita
Projected Total CO2 Emissions
using U.S. per capita rate
(million tonnes)
United States329,000,0004,96515.14,965

You can see that the non-U.S. countries are significantly behind the United States in terms of per capita CO2 emissions, and as industrialization in these countries continues at a rapid pace, there is little reason to assume they will not trend towards U.S.-levels of per capita emissions.

With no other mitigating factors, if those three countries reach U.S.-levels of emissions as projected in the last column on the table above, the CO2 emissions contributed from these four countries together would almost__________.







Although reducing overall consumption and production is the significant factor in curtailing global warming, we have a very long way to go to reach sustainable levels. In the interim, we must develop additional methods to curtail CO2 emissions in the atmosphere.

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