In the final visualization you can explore the same cumulative CO2 emissions 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.