Figure 1: Disproportionate Consumption by the Wealthy (Oxfam 2015)
The richest 10% of people in the world in 2015 were responsible for 49% of CO2 emissions while the poorest 50% of people in the world were responsible for only around 10%.
The extent of Inequalities in consumption and emissions of greenhouse gas equivalents (CO2e) between countries is shown in Figure 2.
According to Chancel (2021), the annual sustainable budget compatible with the 1.5°C limit is 1.1 tonne of CO2e per capita. This value is about six times less than the current global average. The annual sustainable budget compatible with the +2°C temperature limit is 3.4 tonnes per capita.
Figure 2: Average carbon emissions across the world in 2019 (Chancel 2021)
The world average CO2e emissions in 2019 was 6.6 tonnes per capita compared to the average of 20.8 tonnes per capita in North America.
Figure 3 shows historical emissions from 1850 t0 2020 for different global regions.
In 2020, the world had emitted an accumulation of 2,450 billion tonnes of CO2. since 1850. The proportion of this total contributed by region or country are as follows: North America (27%), Europe (22%), China (11%), and the rest of the world (40%). The remaining global budget to stay below +1.5° Celsius before 2050 as agreed upon by the 2015 Paris Agreement was 300 billion tonnes of CO2 emissions. Some countries will have emitted their share of this budget by 2030 (Chancel 2021) and in 2025 we are already close to exceeding +1.5° Celsius (World Meteorological Organization 2024).
Figure 3: Historical emissions versus remaining carbon budget (Chancel 2021)
Figure 4: Countries with the largest cumulative CO2 emissions since 1750
North America and Europe combined were responsible for almost 50% of all historical greenhouse gas compared to 11% for China.
If historical responsibilities were taken into account, then many high-income nations would have no carbon budget left.
Figure 5 shows the inequality of carbon emissions between individuals at the world level.
In 2019, the global bottom 50% emitted on average 1.6 tonnes per capita and contributed 12% of the total emissions. The middle 40% emitted 6.6 tonnes on average, making up 40.4% of the total emissions. The top 10% emitted 31 tonnes (47.6% of the total emissions) and the top 1% emitted 110 tonnes (16.8% of the total emissions).
Figure 5: Average per capita emissions by group in 2019 (Chancel 2021)
Close to 50% of all emissions in 2019 were created by just 10% of the global population.
Inequality also exists within nations. Figure 6 shows per capita emissions by income group in the United States as an example.
The top 10% of the population were responsible for almost 75% of greenhouse gas emission whereas the bottom 50% of the population were responsible for almost 10% of greenhouse gas emissions.
The United States is a prime example of a country with a high level of inequality between the rich and the poor.
Figure 6: Emissions inequality and per capita emissions in the US 2019 (Chancel 2021)
In 2019, the top 10% by income group in the United States emitted almost 8 times as much tonnes of CO2e per capita than the bottom 50%.
The Gini index measures the extent to which the distribution of income or consumption expenditure among individuals or households within an economy deviates from a perfectly equal distribution. A Gini index of 0 represents perfect equality, while an index of 100 implies perfect inequality. Figure 7 shows the increase in household inequality in New Zealand from 1982 to 2016 using the Gini index.
A more recent 2019 publication by the Ministry of Social Development (MSD) shows the extent of unequal share of income of households in New Zealand by quintiles. Quintiles are formed by dividing a population into five equal groups, from lowest to highest. In 2018, the richest quintile of households in New Zealand earned 40% of total NZ income compared to 5% earned the poorest quintile of households. The two wealthiest quintiles owned of 89% of total NZ wealth compared to 3% owned by the two poorest quintiles.
People accumulate wealth over the course of their lives. Many older people have relatively high wealth (often in the form of a mortgage-free home in the main) but low income. Many younger households have lower wealth but higher incomes than many older people. Some of all ages have low incomes and low wealth levels.
Figure 7: Gini index measure of household inequality in New Zealand 1982-2015 (Stats NZ)
The vertical Y-axis show the percentage of global inequality using the Theil index which is used to measure economic inequality. The Theil index measures a distance away from the ideal egalitarian state of everyone having the same income. Greater levels of inequality are indicated by higher percentages of the Theil index. In 1990, most global carbon inequality (63%) was due to differences between countries.
Carbon emission pledges made at the 2015 Paris Agreement are typically expressed in aggregate emissions percentage reductions from a base year. These pledges can be expressed in terms of emissions per capita at a certain time to make better sense of what they imply. These targets do not represent what must be done in order to keep emissions below 1.5 or 2°C. Official commitments do not add up to meeting the 2°C objective, much less to meeting the 1.5°C target.
Figure 8: Global carbon inequality between countries and within countries 1990 to 2019 (Chancel 2021)
In previous years, global carbon inequality was mainly due to inequality between countries.
Global carbon inequalities are now mainly due to inequality within countries.
Domestic emissions inequalities now account for nearly two thirds of global emissions inequality.
Inequality between countries still exists, but there are now even greater inequalities within countries which have serious ramifications if we are to have any success in mitigating the impact of climate change.
Figure 9: Emissions by group versus a 3.0 tonne CO2e per capita climate target by 2030 in the US (Chancel 2021)
All actions to reduce our greenhouse gas emissions involve reductions in consumption.
Material consumption includes consumption of minerals, fossil fuels, and ecological systems which provide both food and resources.
Those on low incomes have less ability to further reduce their carbon footprints than those on higher incomes.
A key to global reductions in greenhouse gas emissions is for all citizens of the world to participate equally.
If those on higher incomes do not participate, then the efforts of all others will be in vain.
Participation can be voluntary or enforced by our institutions. Failing that, nature itself in due course will enforce a reduction in consumption.
Chancel, L. (2021), Climate Change & the Global Inequality of Carbon Emissions, 1990-2020, Summary, World Inequality Lab, Paris School of Economics, pp1-37. https://wid.world/news-article/climate-change-the-global-inequality-of-carbon-emissions/
Credit Suisse (2018) Global Wealth Report 2018. 60pp. https://www.credit-suisse.com/media/assets/corporate/docs/about-us/research/publications/global-wealth-report-2018-en.pdf
MBIE (2023) Energy Hardship Expert Panel and Reference Group. https://www.mbie.govt.nz/building-and-energy/energy-and-natural-resources/energy-hardship/energy-hardship-expert-panel-and-reference-group/
MSD (2019) Household incomes in New Zealand: Trends in indicators of inequality and hardship 1982 to 2018. https://www.msd.govt.nz/about-msd-and-our-work/publications-resources/monitoring/household-incomes/household-incomes-1982-to-2018.html
Oxfam in The Guardian 2 December 2015 https://www.theguardian.com/environment/2015/dec/02/worlds-richest-10-produce-half-of-global-carbon-emissions-says-oxfam
Piketty, T. (2014) Capital in the Twenty-First Century. The Belknap Press of Harvard University Press. 452 pp.
Stats NZ Website https://www.stats.govt.nz
Stiglitz, J. (2012) The Price of Inequality: How Today’s Divided Society Endangers Our Future. New York, W.W. Norton Company.
Wilkinson, R. and Pickett, K. (2009) The Spirit Level: Why Greater Equality Makes Society Stronger. New York, Bloomsbury Press, 374 pp.