The 26th United Nations Climate Change Conference (COP26) starts on Sunday 31 October in Glasgow.
COP26 – Conference of the Parties 26.
It goes on until November 12, leaders from almost 200 countries will gather at this summit, aiming to strengthen the climate targets set in the Paris Agreement at COP21 in 2015.
The goal of this agreement signed six years ago was to limit global warming to well below 2°C, preferably 1.5°C.
However, according to the UN and experts, to achieve this, countries need to commit to more ambitious national targets for cutting greenhouse gas emissions by 2030.
How have global emissions of carbon dioxide (CO2) changed over time?
CO2 Global Emissions
In this chart we see the growth of global emissions from the mid-18th century through to today.
We see that prior to the Industrial Revolution, emissions were very low. Growth in emissions was still relatively slow until the mid-20th century. In 1950 the world emitted 6 billion tonnes of CO2.
By 1990 this had almost quadrupled, reaching more than 22 billion tonnes. Emissions have continued to grow rapidly; we now emit over 36 billion tonnes each year.
Emissions growth has slowed over the last few years, but they have yet to reach their peak. You can add any country or group of countries to the chart below
CO2 Emissions by region
This interactive chart shows the breakdown of global CO2 emissions by region.
We see that until well into the 20th century, global emissions were dominated by Europe and the United States. In 1900, more than 90% of emissions were produced in Europe or the US; even by 1950, they accounted for more than 85% of emissions each year.
But in recent decades this has changed significantly.
In the second half of the 20th century we see a significant rise in emissions in the rest of the world, particularly across Asia, and most notably, China.
The US and Europe now account for just under one-third of emissions.
Year-on-year change in global CO2 emissions
This interactive chart shows the year-on-year growth rate in global CO2 emissions.
A positive figure in a given year indicates that emissions were higherthan the previous year. A negative figure indicates they were lowerthan the year before. For example, a change of 1.5% indicates that global emissions were 1.5% higher than the previous year [–1.5% would mean they were 1.5% lower].
This measure allows us to see the rate at which emissions are changing – whether the growth in global emissions are slowing down or accelerating.
Here you will see that there can be significant year-to-year variability, creating a ‘noisy’ time series. This was particularly true in the first half of the 20th century, where economic output was greatly impacted by key global events (we see large reductions around the World Wars, for example).
In more recent years we see more consistent year-on-year growth averaging around 2% – 3% per year, but still with significant variability. Again, we see the impact of key economic events – the 2008 Financial Crisis resulted in a 1.5% fall in emissions the following year.
Over the past few years, emissions have continued to rise but at a slightly slower rate of 0.5% – 2%.
Where in the world does the average person emit the most carbon dioxide (CO2) each year?
We can calculate the contribution of the average citizen of each country by dividing its total emissions by its population. This gives us CO2 emissions per capita. In the visualization we see the differences in per capita emissions across the world.
Here we look at production-based emissions – that is, emissions produced within a country’s boundaries without accounting for how goods are traded across the world. In our post on consumption-based emissions we look at how these figures change when we account for trade. Production figures matter – these are the numbers that are taken into account for climate targets1 – and thanks to historical reconstructions they are available for the entire world since the mid 18th century.
There are very large inequalities in per capita emissions across the world.
The world’s largest per capita CO2 emitters are the major oil producing countries; this is particularly true for those with relatively low population size. Most are in the Middle East: In 2017 Qatar had the highest emissions at 49 tonnes (t) per person, followed by Trinidad and Tobago (30t); Kuwait (25t); United Arab Emirates (25t); Brunei (24t); Bahrain (23t) and Saudi Arabia (19t).
However, many of the major oil producers have a relatively small population meaning their total annual emissions are low. More populous countries with some of the highest per capita emissions – and therefore high total emissions – are the United States, Australia, and Canada. Australia has an average per capita footprint of 17 tonnes, followed by the US at 16.2 tonnes, and Canada at 15.6 tonnes.
This is more than 3 times higher than the global average, which in 2017 was 4.8 tonnes per person.
Since there is such a strong relationship between income and per capita CO2 emissions, we’d expect this to be the case: that countries with high standards of living would have a high carbon footprint. But what becomes clear is that there can be large differences in per capita emissions, even between countries with similar standards of living. Many countries across Europe, for example, have much lower emissions than the US, Canada or Australia.
In fact, some European countries have emissions not far from the global average: In 2017 emissions in Portugal are 5.3 tonnes; 5.5t in France; and 5.8t per person in the UK. This is also much lower than some of their neighbours with similar standards of living, such as Germany, the Netherlands, or Belgium. The choice of energy sources plays a key role here: in the UK, Portugal and France, a much higher share of electricity is produced from nuclear and renewable sources – you can explore this electricity mix by country here. This means a much lower share of electricity is produced from fossil fuels: in 2015, only 6% of France’s electricity came from fossil fuels, compared to 55% in Germany.
Prosperity is a primary driver of CO2 emissions, but clearly policy and technological choices make a difference.
Many countries in the world still have very low per capita CO2emissions. In many of the poorest countries in Sub-Saharan Africa – such as Chad, Niger and the Central African Republic – the average footprint is around 0.1 tonnes per year. That’s more than 160 times lower than the USA, Australia and Canada. In just 2.3 days the average American or Australian emits as much as the average Malian or Nigerien in a year.
This inequality in emissions across the world I explored in more detail in my post, ‘Who emits more than their share of CO2 emissions?’
Annual CO2 emissions
Who emits the most CO2 each year? In the treemap visualization we show annual CO2 emissions by country, and aggregated by region. Treemaps are used to compare entities (such as countries or regions) in relation to others, and relative to the total. Here each inner rectangle represents a country – which are then nested and colored by region. The size of each rectangle corresponds to its annual CO2emissions in 2017. Combined, all rectangles represent the global total.
The emissions shown here relate to the country where CO2 is produced (i.e.production-based CO2) , not to where the goods and services that generate emissions are finally consumed. We look at the difference in each country’s production vs. consumption (trade-adjusted) emissions here.
Asia is by far the largest emitter, accounting for 53% of global emissions. As it is home to 60% of the world’s population this means that per capita emissions in Asia are slightly lower than the world average, however.
China is, by a significant margin, Asia’s and the world’s largest emitter: it emits nearly 10 billion tonnes each year, more than one-quarter of global emissions.
North America – dominated by the USA – is the second largest regional emitter at 18% of global emissions. It’s followed closely by Europe with 17%. Here we have grouped the 28 countries of the European Union together, since they typically negotiate and set targets as a collective body. You can see the data for individual EU countries in the interactive maps which follow.
Africa and South America are both fairly small emitters: accounting for 3-4% of global emissions each. Both have emissions almost equal in size to international aviation and shipping. Both aviation and shipping are not included in national or regional emissions. This is because of disagreement over how emissions which cross country borders should be allocated: do they belong to the country of departure, or country of origin? How are connecting flights accounted for? The tensions in reaching international aviation and shipping deals are discussed in detail at the Carbon Brief here.
Consumption-based (trade-adjusted) emissions
CO2 emissions are typically measured on the basis of ‘production’. This accounting method – which is sometimes referred to as ‘territorial’ emissions – is used when countries report their emissions, and set targets domestically and internationally.5
In addition to the commonly reported production-based emissions statisticians also calculate ‘consumption-based’ emissions. These emissions are adjusted for trade. To calculate consumption-based emissions we need to track which goods are traded across the world, and whenever a good was imported we need to include all CO2emissions that were emitted in the production of that good, and vice versa to subtract all CO2 emissions that were emitted in the production of goods that were exported.
Consumption-based emissions reflect the consumption and lifestyle choices of a country’s citizens.
Which countries in the world are net importers of emissions and which are net exporters?
In the interactive map we see the emissions of traded goods. To give a perspective on the importance of trade these emissions are put in relation to the country’s domestic, production-based emissions.6
- Countries shown in red are net importers of emissions – they import more CO2 embedded in goods than they export.For example, the USA has a value of 7.7% meaning its net import of CO2 is equivalent to 7.7% of its domestic emissions. This means emissions calculated on the basis of ‘consumption’ are 7.7% higher than their emissions based on production.
- Countries shown in blue are net exporters of emissions – they export more CO2 embedded in goods than they import.For example, China’s value of -14% means its net export of CO2is equivalent to 14% of its domestic emissions. The consumption-based emissions of China are 14% lower than their production-based emissions.
We see quite a regional East-West split in net exporters and importers: most of Western Europe, the Americas, and many African countries are net importers of emissions whilst most of Eastern Europe and Asia are net exporters.
You can find these figures in absolute (tonnes of CO2) and per capita terms for each country in the Additional Information section.
How has each country’s share of global cumulative CO2 emissions changed over time?
In the final visualization you can explore the same cumulative CO2emissions as you have seen above but now visualizes by country. Using the timeline at the bottom of the chart you can see how contribution across the world has evolved since 1751. By clicking on a country you can see an individual country’s cumulative contribution over time.
The map for 2017 shows the large inequalities of contribution across the world that the first treemap visualization has shown. The USA has emitted most to date: more than a quarter of all historical CO2: twice that of China which is the second largest contributor. In contrast, most countries across Africa have been responsible for less than 0.01% of all emissions over the last 266 years.
What becomes clear when we look at emissions across the world today is that the countries with the highest emissions over history are not always the biggest emitters today. The UK, for example, was responsible for only 1% of global emissions in 2017. Reductions here will have a relatively small impact on emissions at the global level – or at least fall far short of the scale of change we need. This creates tension with the argument that the largest contributors in the past should be those doing most to reduce emissions today. This is because a large fraction of CO2 remains in the atmosphere for hundreds of years once emitted.4
This inequality is one of the main reasons which makes international agreement on who should take action so challenging.
Authors: Hannah Ritchie and Max Roser – Reproduced with all permissions under this Creative Commons BY license
Hannah Ritchie and Max Roser (2020) - "CO₂ and Greenhouse Gas Emissions". Published online at OurWorldInData.org. Retrieved from: 'https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions' [Online Resource]
