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Per capita, national, historical: how do countries compare on CO2 metrics?

There are many ways to measure countries’ contributions to climate change. What do they tell us?

There is a never-ending fight about who is ‘responsible’ or ‘to blame’ for climate change. That often leads to debates about who should take action to tackle it.

But there is no single metric that captures the distribution of CO2 emissions across the world, today or in the past.

We can compare the total emissions of countries every year. But this fails to take account of population size; you’d expect a country with more people to have higher emissions. Even then, comparisons of total or per capita emissions today don’t capture historical contributions. Some countries that now have relatively low emissions have had high emissions for centuries.

These metrics tell us different things.

To ensure that people can have an informed discussion about the complexities of global emissions, we make all of them readily available on Our World in Data. You can explore them in more detail in our Greenhouse Gas Emissions Data Explorer.

But here, I will also give a quick overview of the main metrics.

Annual CO2 emissions by country

Emissions are most commonly aggregated and reported at the national level.

Annual CO2 emissions tell us how much each country emits in a given year. It shows us the geographical distribution of current emissions across the world.

In the chart, you can see how much each country emitted in the most recent year.

Note that these are emissions from fossil fuels and industry – land use change is not included [but you can find that data in our explorer]. And they are domestic emissions that do not account for traded goods. We will look at trade-adjusted emissions later.

Annual emissions tell us about the countries contributing the most to climate change today. It’s the total amount of emissions that matters for the climate; these breakdowns help us understand how different countries are contributing to that total.

Per capita CO2 emissions

Annual national emissions do not take population size into account. All else being equal, we might expect that a country with more people would have higher emissions.

Emissions per person are often seen as a fairer way of comparing. Historically – and as is still true in low- and middle-income countries today – CO2 emissions and incomes have been tightly coupled. That means that low per capita emissions have been an indicator of low incomes and high poverty levels.

That puts more emphasis on countries with high per capita emissions – who are typically much richer – to reduce their emissions quickly, to ‘make space’ for poorer countries to grow. Many richer countries are achieving this (although not fast enough).

As you can see in the map, there are large inequalities in emissions per person worldwide.

Historical CO2 emissions by country

Carbon dioxide can stay in the atmosphere for centuries. That means that CO2 emitted in the 1800s is still driving climate change today.

We tend to focus on emissions happening today. This makes sense since it’s where we can actually take action to reduce them. But it’s also important to consider the historical contributions that countries have made.

The UK, for example, burned large amounts of coal over many centuries. Its economy and wealth were built on industries powered by fossil fuels. It now has high standards of living as a result. The same is true of many other rich countries.

So while these countries might account for a small share of emissions today, they have contributed significantly more over time.

How does this affect the distribution of responsibility today?

The reality is that if we’re to tackle climate change, the rest of the world cannot follow the high-carbon development pathways that the UK and other rich countries followed. But it’s unacceptable to expect them to choose between lifting people out of poverty and keeping their emissions low. That means that the low-carbon energy options must be compatible with poverty reduction: they need to be cheaper than fossil fuels.

Rich countries, then, could play a greater role by not only reducing domestic emissions but by financing and investing in low-carbon technologies elsewhere. They could use their wealth and infrastructure – which have contributed to climate change – to develop low-carbon pathways for the rest of the world.

In the chart, you can see each country’s historical contributions to CO2 emissions.

CO2 emissions adjusted for trade

So far, the data has focused on domestic emissions. This is the amount that is emitted within a country’s borders. But, countries export and import products from abroad. These ‘traded emissions’ are not included in national accounts.

So, if the UK imports batteries from China, the CO2 emitted in producing them is allocated to China.

We can adjust for this using a method called ‘consumption-based’ accounting. This adds the emissions that a country ‘imports’ and subtracts what it ‘exports’.

In the chart, you can see which countries are net exporters (in red) and net importers (in blue).

Overall, richer countries across Europe and North America tend to be importers. Middle-income countries – particularly across Asia – tend to be net exporters.

We provide more data on consumption-based emissions in a dedicated article, which includes each country’s annual and per capita emissions after adjusting for trade:

How do CO2 emissions compare when we adjust for trade?

Which countries are net importers and exports of emissions? How much CO2 is ‘offshored’?

Cite this work

Our articles and data visualizations rely on work from many different people and organizations. When citing this article, please also cite the underlying data sources. This article can be cited as:

Hannah Ritchie, Pablo Rosado and Max Roser (2023) - “Per capita, national, historical: how do countries compare on CO2 metrics?” Published online at OurWorldInData.org. Retrieved from: 'https://ourworldindata.org/co2-emissions-metrics' [Online Resource]

BibTeX citation

@article{owid-co2-emissions-metrics,
    author = {Hannah Ritchie and Pablo Rosado and Max Roser},
    title = {Per capita, national, historical: how do countries compare on CO2 metrics?},
    journal = {Our World in Data},
    year = {2023},
    note = {https://ourworldindata.org/co2-emissions-metrics}
}
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