Paris Agreement per capita

When talking about global emissions, it is common to break them down by sources or economic sectors such as agriculture, electricity generation or industry. However, it is not as straightforward to identify the emissions for which we are responsible at an individual level because most of them are hidden behind the products and services we benefit from every day. This article will take a look at what it takes at an individual level to meet the 2°C target by 2100 from the Paris Agreement.

Carbon budget

There is a direct relationship between the increase in the global average temperature and the total cumulative emissions released in the atmosphere. For a likely probability (i.e. with 66% confidence) to stay below the 2°C target by 2100, the world has a remaining carbon budget of 788 GtCO2 which represents only 37% of what has already been emitted from 1870 through 2017. With annual greenhouse gas (GHG) emissions of around 50 GtCO2e, this carbon budget will last a little more than 20 years.

GHG footprint: top-down

The two previous articles “Enerconomy” and “Global emissions: what fractions capture our attention?” have touched on the issue that our economy is built upon the consumption of energy and that we, as individuals, directly or indirectly contribute to an environmental impact when we interact with that economic system. The indicator “GHG emissions per capita” is a top-down approach that quantifies the average GHG emissions created by an individual as a result of the use of all the products and services (e.g. industries, agriculture, electricity, transports) in his country.

In 2014, with World Bank reporting a global population of around 7.270 billion, the average GHG emissions per person (also to referred to as “individual GHG footprint”) was approximately 6.5 tCO2e/capita per annum (including international aviation and navigation but excluding LULUCF). The graph below from the Climate Action Tracker 2018 indicates that if we are to be consistent with a 2°C pathway, global emissions will have to peak around 2020 at no more than 54 GtCO2e, come down to 18 GtCO2e by 2050 and reach close to net zero by 2100.

According to the World Population Forecast (2020 – 2050), by 2050, with a population projected to reach around 9.770 billion and assuming that we would all share the effort equally, the world average GHG emissions per capita will thus have to shrink to 18/9.770 ≈ 1.8 tCO2e/capita per annum. In other words, the average individual GHG footprint will have to be divided by 3.6 in 30 years to be consistent with a 2°C pathway.

Although the world average individual GHG footprint is around 6.5 tCO2e/capita per annum, there is a large variability between countries. The graph below compares the individual GHG footprint of 14 countries. These have been calculated using the latest emissions data reported to the UNFCCC and the population data from the World Bank.

The content of the GHG footprint also varies widely between countries as per the graph below. This graph illustrates why an effective mitigation strategy cannot be unique but instead, it has to be tailored to the specificities of each country. For instance, countries like New Zealand and Brazil would do better to focus on agriculture while a country like Russia would allocate more effort on preventing fugitive emissions.

GHG footprint: bottom-up

One may argue that the simple calculation of the total GHG emissions divided by the population is a socio-economic indicator that only reflects an average trend. Every individual has a different environmental impact, and probably no one is close to being an average person. Moreover, all inhabitants of a country cannot be held responsible for the emissions induced by the production of goods and services that will later be exported and sold in other countries. Part of the GHG footprint of exporting regions like south-east Asia could arguably be assigned to importing regions like western Europe. Hence, this top-down approach does not provide sufficient insight on how to identify individual sources of emissions in practice and should be completed with a bottom-up analysis.

The following graph displays the GHG content of some of our daily products and services compared with the individual 2°C pathway annual budget needed by 2050 (ADME, 2018). Even though most of the emission factors used to plot this graph have a reasonably high uncertainty range (±50%), the orders of scale remain insightful. To calculate the individual GHG footprint, one simply has to add up all the emissions contained in his daily actions over the whole year.

This short outlook reveals that under current energy use, technology and social norms, constraining all individual GHG footprints in 30 years to stay in line with the Paris Agreement is a daunting challenge. Some things can be done at a personal level to limit our emissions, and some actions are easier and have more potential than others. However, whether we will suddenly decide to all shrink our footprints in a global collaborative effort to the level required to meet the Paris Agreement in a world dominantly ruled by democracies is somewhat doubtful.