In global economic circles, for practical purposes, countries are grouped into buckets. The World Bank Group and the International Monetary Fund, for example, use a classification that distinguishes between low-, middle-, and high-income economies. They use GDP as a key metric of overall economic development: Countries in the upper-income bracket are considered “developed”—although there isn’t an exact correspondence between “high-income” and “developed”—and the others are deemed to still be “developing.” In broad terms, the goal is for all countries to become “developed.”
This unidimensional concept of economic development obviously has its limitations. Notably, it does not directly consider matters related to distribution and welfare. Nevertheless, per-capita GDP classifications have remained robust as a broad measure of development, and it is widely used for analytical purposes as well as for allocating concessional aid and access to other financial resources.
A new nomenclature for emissions
In international environmental law, the concept of “common but differentiated responsibilities (CBDR)” establishes a responsibility framework for all countries to protect nature, while recognizing that states differ both in their contribution to global problems and in their capacity to respond. In practice, CBDR has not enjoyed strong support among “developed” countries, because they have not accepted any legal or quantitative definition of the damage they have caused by historical greenhouse gas emissions, and because the responsibilities of “developing” countries are not clearly demarcated and accepted. This is starting to change in the dimension of climate action, and it can be helped if the world establishes a robust per-capita emissions framework. Most countries, developed and developing, including all large emitters, have made voluntary pledges to reach net zero in the context of the United Nations Framework Convention for Climate Change. It might now be time to integrate these two concepts—the contribution and capacity to respond.
Take the World Bank’s income classification and the corresponding country groupings that are readily available in the World Development Indicators database. Starting July 1, 2023, the classification of each country is determined by its gross national income per capita, measured in market prices (U.S. dollars):
|1,136 – 4,465
|4,466 – 13,845
Low-income and some lower-middle-income countries have access to concessional funds, while lower-middle-income and upper-middle-income countries can borrow from the World Bank on non-concessional terms. Some upper-middle-income countries have restricted access, and few high-income countries have any access to non-concessional financing.
In today’s world, income should not be the sole determinant of access to international finance. We can add a second dimension that captures per capita emissions intensity, easily obtained from the World Emissions Clock. The clock shows that the current global average of per capita emissions—including imputed values for methane—is about 7.4 tons per person per year. Using this as a benchmark, we can propose a very intuitive classification:
|Low emission countries (LECs)
|<5 tons per capita
|Medium emission countries (MECs)
|5 to 10 tons per capita
|High emission countries (HECs)
|> 10 tons per capita
An income-emissions classification
Combining the two classifications yields a 3×3 matrix. Less than half of all countries (80 out of 183) fall along the diagonal of high income/high emissions, middle income/middle emissions, and low income/low emissions, suggesting that there is considerable variation within each income category as to the level of emissions. That is why adding this dimension to the classification provides useful new information and insights. The overall results are shown in Table 1 where 183 countries are sorted into their respective categories.
The analysis conveys five main insights:
- Low-income countries account for a small fraction of global emissions, around 2.3 gigatons or 4% of the total, albeit disproportionally higher—about 10 times higher—than their weight in global GDP (0.4%). This gap is largely explained by the continued degradation of land and forests in these countries.
- Most new emissions today emanate from the 99 middle-income countries in the world. This is perhaps unsurprising as 6 billion of the 8 billion people on our planet live in these countries. But most of the historical emissions have come from high-income countries. This makes global policy decisions difficult.
- Two-thirds of middle-income country emissions come from just 20 countries. This group includes China, now the world’s largest emitter, but Mongolia, Kazakhstan, and Brazil (Table 2) have higher per capita emissions than China, and the rate of growth of emissions in India is also rapid.
- Almost half of all high-income countries (26 out of 56) have low or medium levels of emissions. Being rich does not require having high emissions.
- Much more needs to be done. The global goal is to shift all countries to the top-right corner; high-income levels and low-emission levels. Currently, only 1 in 200 people on the planet live in such countries (see Table 2 for country illustrations).
Target emissions, not energy sources
As expected, rich countries emit substantially more than poorer countries. But the general trend masks a surprisingly large variance within each group. Indeed, there are countries in each of the nine income-emission combinations: There are high-income countries with low emissions, such as Chile, Malta, and Romania. Until mid-2022, there was even one low-income country that had high emissions, which is Zambia—due to a high rate of land degradation. It has since re-joined the middle-income group. What this means is that it is possible to be rich or become rich with low emissions. It also means that being income-poor does not automatically imply a low climate footprint.
Emissions reduction should become a policy target alongside income growth. Expecting upper-middle-income economies to grow to high income without some phase out of fossil fuels is not a realistic goal, but expecting high emitters to reduce per capita emissions is a reasonable ask. Indeed, countries should work hard to reduce any portion of their emissions footprint. Transitioning from a middle-emitting country to a low-emitting country should be celebrated as much as moving from middle-income to high-income.
Acknowledgements and disclosures
Authors of this commentary, including Homi Kharas and Wolfgang Fengler, provide academic expertise through World Data Lab’s non-profit division, a data source referenced here. The views expressed in this commentary are solely those of the authors.