CO2 Emissions by Country: What's Up?

As the Paris Accord consumes more of our attention, I thought it might be fun to look at some numbers. We know that countries will invest resources in policies designed to curb CO2 emissions. But we don’t know all the determinants of a country’s capacity to create CO2. My little data analysis comes up short with respect to a smoking gun. There is some interesting dirt, however.

I started out with a simple model that says that the amount of CO2 a country emits ought to have something to do with fundamentals like size of the economy, the population, and, of course, its number of cows. I look at these relationships and find some corroboration. But it is very clear from the data that there are other factors that are important. As the world moves forward with CO2 policies, it behooves us to be more clear about what actually causes CO2 to be high/low for a country. Clearly one-size-fits-all policies make no sense. 

The US was the world’s second largest CO2 emitter in 2015, behind only China. The next biggest emitters were India, Russia, Japan, Germany, Iran, South Korea, Canada and Saudi Arabia. (Table in million of metric tons, https://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions)

CO2s   Rank China 10642 1 US 5172 2 India 2454 3 Russia 1761 4 Japan 1253 5 Germany 778 6 Iran 633 7 Korea 617 8 Canada 555 9 Saudi Arabia 506 10

Guide to below tables. The order of each table's rows is in terms of CO2 emissions above. The rank found in the rank column in each table below refers to rank of the item being displayed. In this way we can quickly see how each of these factors correlates to a country's emissions. 

The size of the economy should have something to do with CO2 emission. And it seems to hold true since the US and China are very large emitters and have large economies. (World Bank, mostly 2015 data, nominal GDP in billions)

Economy     Billions        Rank China  11,158  2 US  18,037  1 India  2,116  5 Russia  1,326  8 Japan  4,383  3 Germany  3,364  4 Iran  425  10 Korea  1,378  7 Canada  1,553  6 Saudi Arabia  653  9

But this simple relationship between emissions and size of economy breaks down because Russia is the 8th largest economy but the 4th largest emitter. Iran, the 7th largest emitter, has the 10th largest economy. Its economy is tiny compared to the others.

Next, I calculated a statistic for each country that is found by dividing the amount of CO2 emitted by the size of the economy. If the economy size was the key explanation for how much a country emits, then the size of this stat should be similar for each country. 

C02 per Economy       Rank China 0.95 4 US 0.29 8 India 1.16 3 Russia 1.33 2 Japan 0.29 9 Germany 0.23 10 Iran 1.49 1 Korea 0.45 6 Canada 0.36 7 Saudi Arabia 0.77 5 Median 0.60

The US is the largest economy and the 8th largest emitter in terms of CO2 per nominal GDP, with a value of 0.29. Notice that value for the US is half the median country (0.6) value and about one-sixth the value of Iran’s value of 1.5. India’s CO2 output per unit of GDP is four times the US value. The US, Japan, and Germany are under-polluting (higher ranks) based on CO2 per GDP. Iran, Russia, India and China over-pollute relative to GDP.

This statistic varies a lot by country. Iran’s score is about four times that of the US. Russia’s is close to three times the US value. Germany has the lowest statistic of any of the 10 countries at 0.23. These numbers suggest that there is something other than the size of the economy that determines how high a country ranks on emission.

So naturally I turned to cows. Luckily there is data on cows by country and I calculated the emission of CO2s per cow in each of these countries.

Co2 per       Cow        Rank China 93 4 US 58 8 India 13 10 Russia 88 5 Japan 313 2 Germany 60 7 Iran 70 6 Korea 206 3 Canada 46 9 Saudi Arabia 1012 1

Again, the range was wide from a score of 1012 Co2s per cow for Saudi Arabia to a low of 13 for India. Perhaps the flatulence of Saudi cows is higher than those of Indian cows. But the message is clear. We cannot explain the ranking of emitters by number of cows. There must be something else.

The ranking of countries by population is almost identical to the ranking of emitters.

	Population			Rank
China		1.376	1
US		0.322	3
India		1.311	2
Russia		0.144	4
Japan		0.127	5
Germany		0.081	6
Iran		0.079	7
Korea		0.053	8
Canada		0.036	9
Saudi Arabia		0.032	10

(Population is in billions)

But higher population does not mean proportionally more emissions. When I calculate emissions per person for each country (table below), there is still a lot of variability from a value 16,073 for the US to only 1,872 for India. Emissions of countries with large populations like China and India are not proportional to population. Whew. Less populated countries like Saudi Arabia and Canada tend to have higher CO2 scores per person. More interesting are the US and Russia who have large populations and CO2 per person.

	CO2 per
	Person	Rank
China	7,734	9
US	16,073	1
India	1,872	10
Russia	12,275	5
Japan	9,900	6
Germany	9,641	7
Iran	7,504	8
Korea	12,267	4
Canada	15,441	3
Saudi Arabia	16,049	2

The last table below brings all this together. Here we see how each country did with respect to ranking on CO2 per GDP, per person, and per cow. Remember, a low rank (e.g. 1 or 2)  means more CO2 emission. So a low number is a high score on pollution -- a low number below is "bad". Thus a high number is "good".

The countries with the lowest scores and the worst CO2 rankings are S. Arabia, Russia, S. Korea, and Iran. For Russia and Iran the lowest rankings relate to higher CO2 per GDP.  Saudi Arabia gets poor scores because of high CO2 per person and per cow.

The countries with the highest (best) numbers did best on pollution emission. Germany was good across the board while India did well on account of not polluting in proportion to their large populations of people and cows.

The remaining countries were mostly in the middle. The USA, however, scored very poorly on CO2 per person though the USA did well when comparing CO2 to GDP. Japan doesn't seem to have enough cows.

Yes, some of this is facetious. But I reported it all for several reasons. First, I was well into my JD. Second, there might be some interpretations when you break down the numbers. It is obvious why a country with a huge population might have a small CO2 output per person or cow. But less obvious why China's CO2 per GDP is pretty strong despite having a very large GDP. Finally, this analysis suggests that any one-size-fits-all remedies may not succeed. CO2 emission might be strongly related to size of population, GDP, number of cows, policy or other things. What each country can or should do to improve CO2 should be the subject of much more analysis and discussion than I am hearing these days. We all nod when someone says that money and technology will solve the problem. I'm not sure it is that simple.

Summary of Ranks 
CO2 per
             GDP   Person   Cow   Sum
China      4            9           4        17
USA        8            1           9       17
India        3          10         10       23
Russia      2            5           5      12
Japan       9            6           2       17
Germany 10          7           7       24
Iran            1          8           6       15
S Korea     6          4            3       13
Canada      7           3           9       19
S. Arabia    5          2           1         8