Just 1% of the world’s population was responsible for almost a quarter of greenhouse gas emissions over 1990-2019, new research finds.
According to the study, people in sub-Saharan Africa emitted 1.6 tonnes (tCO2e), each on average in 2019. In North America, average per capita was more than 10 times higher, while the top 10% of the continent’s emitters produced almost 70tCO2e.
To have a “high” chance of limiting global warming to 1.5C above pre-industrialThe study concludes that temperatures will need to drop to 1.9 tCO2e per capita by 2050.
Researchers often consider the emissions from the goods and services people consume when assessing individual contributions to global climate change. This study presents an update to this method by also including the emissions from a person’s investments in their greenhouse gas footprint. This allows the study to more accurately represent the emissions of the wealthy — which largely come from investments.
“Individuals can consume carbon, but they can also own [and invest in] firms that produce carbon,” the lead author of the study tells Carbon Brief, adding that his work “is proposing a method that is going to integrate these different bits of our carbon footprints together”.
The results show that the largest source of emissions for the top one percent of emitters was investment, with the period 1990-2019 being the focus. The per capita emissions of top 1% increased by 26%, while those of top 0.01% experienced an increase of 80%.
Wealth and Emissions
Humans release billions of tonnesEach year, the atmosphere releases approximately 1.2 million tons of CO2. These emissions are however disproportionately generated by the wealthy, who tend to live more carbon-intensive lifestyles.
Recent researchAccording to the study, the average person in sub-Saharan Africa emits 0.6 tonnes of carbon dioxide (tCO2) per year, while the average American citizen produces 14.5tCO2. Carbon BriefAnalyses have also shown that the US is responsible alone for one-fifth (or 1%) of all CO2 emitted since 1850.
The new paper uses a wealth and income inequality dataset from World Inequality DatabaseIt tracks inequality from 1990 to 2019. It combines economic data with information on per-capita carbon footprints — calculated using “input-output” methodologies combined with data from the “distributional national accounts” project.
The paper assesses three components of a person’s greenhouse gas footprint. The first is private consumption — made up of emissions from the direct use of fuel and emissions embedded into goods and services. The second includes emissions from government spending in that person’s country — such as government administration, public roads or defence.
The final component of a person’s carbon footprint is investment. Dr Lucas ChancelFrom the Paris School of EconomicsThe new study was solely written by. Carbon Brief was told by him that investors in companies are responsible for the emission produced by their day-today activities.
Chancel focuses on the global inequalities between high emitters and low emitters.
“I find that, in 2019, the bottom 50% of the world population emitted 12% of global emissions, whereas the top 10% emitted 48% of the total.”
The study covers 174 countries. He demonstrates the differences in emission levels between high- and low-emitters in each country. Below is a plot showing the tonnes of CO2 equivalent that are emitted per capita per year by the top 10% (red), 40% (dark) and 50% (light) emitters in different regions.
Sub-Saharan Africa has low per-capita carbon emissions. The bottom half of the emitters emit just 0.5tCO2e per year, while the top 10% emit about 7.5tCO2e.
However, even the lowest 50% of North American emitters have annual emissions exceeding 10tCO2e. Meanwhile, the top 10% of the continent’s emitters are responsible for almost 70tCO2e every year.
Dr Anne Owen — a senior research fellow at the University of Leeds, who was not involved in the study — tells Carbon Brief that this is “an ambitious and impressive piece of work”, adding that the “robust” data and methods “allow for a consistent comparison between countries”.
The paper examines how per capita emissions have changed between 1990 and 2019, for different emitting countries. It shows that global per-capita emissions increased by more that 2% since 1990, but that this growth wasn’t uniform across emitting groups.
Chancel tells Carbon Brief that the broad trends in emissions inequality have not changed much over the study period, but notes that “at the very top of the distribution, you see quite a bit of action”.
He found that the per-capita global emissions of the top 1 percent of emitters grew by 26% between 1990 and 2019. The top 0.01% experienced an even greater rise of 80%. However, the per-capita increase in emissions for the bottom 0.01% was only 16%. And the “lower- and middle-income groups of the rich countries” saw a drop in per capita emissions of 5-15%.
This is evident in the chart below. It shows the percentage change of per-capita emissions over the period 1990-2019 (blue line). In general, individuals in richer countries fall into the “higher emitting” groups, and are found on the right of the chart, while the lowest emitters are found on the left.
Dr Narasimha Rao – an associate professor of energy systems at the Yale School of Environment, who peer reviewed the study – tells Carbon Brief that it is “striking”, but “unsurprising” to see “the disproportionate growth in the emissions of the global elite around the world”.
According to the paper, global emissions have also been affected by growing inequality in countries over the past three decades.
It finds that, in 1990, while the average citizen of a rich country “polluted unequivocally more” than much of the rest of the world, the wealth gap between individuals within the same country was “on average lower across the globe than today”. However, “the situation has entirely reversed in 30 years”, the study says.
This is shown in the right-hand graph. It shows that inequality between countries (red) was the largest driver of global inequality in 1990. In 2019, this had changed so that within-country emissions inequality was the dominant driver (blue lines).
In other words, global emissions inequality was once primarily driven in 1990 by differences between residents of richer or poorer countries. However, it is now increasingly driven in part by differences in emissions within each country, whether they are rich or poor.
“Economic inequality within countries continues to drive a lot of the dynamics that we observe in terms of pollution,” Chancel tells Carbon Brief. He adds that understanding these inequalities is “key” to understanding “how to solve the climate crisis”.
The Top 1%
A group of researchers published a publication in February 2022. studyOn the global inequality of carbon emissions. It found that the average carbon footprint for the top 1% of emitters is more than 75 times higher than that of the bottom 50%.
Dr Wiliam Lamb – a researcher at the Mercator Research Institute, who was not involved in the study – praised the paper. He said however that he was not involved in the study. Carbon Brief that by focusing solely on consumption, the paper did not accurately capture the emissions of the “super-rich”, as “their earnings may be derived from investments while their expenditures can be shrouded in secrecy”.
Chancel tells Carbon Brief that “people who think about carbon footprints just from the point of view of consumption don’t have the entire picture”. By using a “systematic combination of tax data, household surveys and input-output tables” the new study is able to more fully represent the emissions of the very wealthy, it says.
“Individuals can consume carbon, but they can also own [and invest in]Companies that produce carbon. So here the exercise is proposing a method that is going to integrate these different bits of our carbon footprints together in a consistent framework where I’m not counting the same tonne of carbon twice.”
The plot below shows the percentage of emissions from different emitter groups that come from investments — rather than consumption of goods and services or government spending.
The majority of emissions from the top 1% of emitters can be traced back at investments, the study shows. It also found that the share of emission linked to investment has increased for the top 10% emitters over the past decade, but has declined for the bottom 50%.
Chancel says that this change in investing patterns was driven by increasing wealth gaps between countries.
Dr Klaus Hubacek — a professor of science, technology and society at the University of GroningenAuthor of the study published earlier this year — tells Carbon Brief that he is “excited” about the inclusion of investments in this study and that “more effort needs to go into that direction”.
Chancel compares the current-day emissions with those required to limit warming to 1.5C and 2C above preindustrial levels to put these results in context.
The plot below shows average carbon footprints in different regions of the world in 2019 and the average global emissions needed to limit warming to 1.5C or 2C – assuming that emissions are split evenly across the global population.
The plot shows that in order to limit warming to 1.5C, per-capita average emissions must drop by more than two thirds from their 2019 value (6tCO2e). This would mean that all regions, except subsaharan Africa, must reduce their emissions. North American citizens would need to reduce their emissions more then 10-fold to reach the target.
In addition, a “large part of the population in rich countries already appears to be near 2030 national climate targets when these are expressed in per-capita terms”, the paper notes.
For example, it says, “nationally determined contributions (NDCs) established under the rubric of the Paris Agreement imply a per-capita target of around 10t of CO2e in the US”. Below is a chart that shows per-capita 2019 emissions by income group (left) as well as how much they would need to change in order to reach the 10tCO2e target for the US and China for 2030 (right).
The US would require the 10% richest 10% to reduce their emissions by nearly 90% in order to meet the 2030 emission reduction target. The bottom 50% of emitters, however, would not need to make any changes.
China’s differences between emitter groups are even more apparent. The study shows that all but the top 10% could keep below their individual greenhouse gas allowances, even though their emissions rise significantly between now and 2030. However, the top 10% of the country’s emitters would need to slash emissions by around three-quarters.
“Much is written about the emissions-intensive growth of people buying new appliances and cars as they rise out of poverty”, Rao tells Carbon Brief. However, he says this study “starkly reveals the need to focus on luxury emissions”.
Chancel tells Carbon BriefHe stated that he would love to see governments keep track of how their country’s emissions, much like they do with data on wealth and GDP. “There is a lot of work ahead,” he says.