What is a CO2 baseline methodology?

What is a CO2 methodology for carbon footprint?

A CO2 calculation methodology specifies how CO2 emissions are accounted for, in particular with regards to their scope and emission factors.

The carbon footprint you are proposed to make is based on the international principles established by the UNFCCC, which are recalled in the chapter "Understanding our data" of the CITEPA SECTEN report.

The carbon footprint calculator is free to access (open source) and anyone can modify and add to it, on the page https://github.com/CompteCO2/Carbon-Weight.

The calculator evaluates CO2 emissions, based on the formula

CO2 emissions = quantity consumed x emission factor.

In this article, we explain in detail how the quantities consumed are determined, as well as the choice of the emission factors used, provided by CITEPA.

An essential point of the methodologies concerns the problem of "double counting", which must be avoided at all costs. For example, the UNFCCC guidelines for the preparation of GHG emission inventories provide for the sole consideration of emissions related to national activities within borders (territorial approach). The methodology therefore does not take into account the significant upstream GHG emission flows linked to the countries producing the goods consumed in the inventory country (so-called imported emissions). Consequently, the GHG emissions associated with goods imported for domestic consumption of the States do not appear in their national inventories. Conversely, the emissions associated with goods manufactured in the producing countries and exported are accounted for in the national inventories even though these exported goods are not consumed locally.

This fundamental principle of not double counting emissions means that electricity consumption is rounded up to zero CO2 emissions in the proposed methodology. Indeed, electricity producers are already under CO2 quotas regulation (EU-ETS), so they are counting your CO2 emissions for you.
On the other hand, it turns out that in France the production of one kWh of electricity emits ON AVERAGE only around 22 grams of CO2 (source RTE Eco2mix).
With this 1 kWh of electricity, i.e. 22 g of CO2, you get the same heat to heat your home as if you had burned 0.3 litres of fuel oil and emitted 800 grams of CO2. In France, electricity consumption therefore emits about 40 times less CO2 than fuel oil.
If, in the long term, electricity production is 100% hydraulic, wind, solar and nuclear, we will be very close to zero grams of CO2 per kWh produced.

The calculation proposed here therefore corresponds to a carbon balance, rather than a carbon footprint, which would be more exhaustive and could even incorporate data relating to the Life Cycle Analysis (LCA) of the products consumed.

Although by design this carbon balance is approximate, or even false as we explain here, it is nevertheless the first fundamental step in understanding one's CO2 emissions and finding solutions to reduce them.

In particular, for France, according to the CO2 methodology used by CITEPA, in 2021, 30.1% of GHG emissions are linked to the transport sector, 19.4% to agriculture, 17.9% to the residential and tertiary building sector, 18.6% to manufacturing industry and construction, 10.5% to the energy industry, and 3.5% to centralized waste treatment.

Transport, food and buildings are therefore the three most important CO2 emission sectors in our country. They are also the three areas on which we can act individually on a daily basis....and for which there are carbon-free solutions. Unsurprisingly, the carbon footprint we are proposing to you therefore focuses on these three essential sectors.

France's average CO2 emissions per capita

According to the CITEPA report and CO2 methodology France's emissions in 2021 amount to 418.2 million tons of CO2.

To this figure must be added emissions from international air transport, i.e. 8.8 Mt of CO2 in 2021 (the 2020 and 2021 figures are lower than those of 2019 at 19.2 Mt of CO2, taking into account the COVID crisis) according to the DGAC, as we explain in the paragraph below.

We have also chosen to add to these two figures the emissions linked to the average food consumption of the French. CITEPA estimates 81.2 million tons of CO2 for all French agriculture in 2021. However, it does not detail the emissions per foodstuff.

We therefore prefer to use the average estimates of French food consumption that we can establish from ADEME data. The latter estimates that a French person emits 2,563 kgCO2e per year for food (the details of the calculation are presented in a paragraph below).

Since, according to INSEE, the French population will be 67.626396 million on 1 January 2021, we can estimate the emissions from our food at 173.32 million tons of CO2 (2.563 x 67.626396).

France's total emissions in 2021 are therefore equal to 418.2+8.8+173.32 -81.2= 519.12 million tons of CO2.

We deduce that the average emissions per French person in 2021 are 7.68 tons of CO2/inhabitant (519.12/67.626396).

In the carbon footprint, we calculate the value of the average emissions per inhabitant for the four most important items, ground and air transports, housing, and food. The total of these four items amounts to 4.58 tCO2/capita. The difference between these 4.58 tons and the national average of 7.68 tons, i.e. 3.10 tons, corresponds to our indirect emissions, those that are necessary for us to buy products in shops (production and transport of products), to go to school and hospital, etc...

Average French CO2 emissions by sector and per capita

Average car emissions in France per capita

For the year 2021, the total emissions from passenger cars and two-wheelers calculated in the CITEPA SECTEN report amount to 67.73 million tons of CO2.

This figure, when compared to the 67.62 million inhabitants, gives a national average of 1.00 ton of CO2 per inhabitant (67.73/67.626396 = 1001 kg of CO2 rounded to one ton).

This figure does not take into account all French road transport emissions, i.e. 119.6 million tons of CO2 in 2021, in order to compare only the emissions of our private cars given by the carbon calculator, with the national average of our private cars.

The specific emissions factors and CO2 methodology for transport are given here: the carbon footprint of my car.

Average housing emissions in France per capita

The SECTEN data from CITEPA reports a total of 47.8 million tons of CO2 for residential buildings and domestic activities in 2021.

For 67.064 million inhabitants, this means a national average of 0.71 tons of CO2 per inhabitant (47.8/67.626396).

This figure does not take into account the use of our tertiary buildings, i.e. 27.1 million tons of CO2 in 2021, in order to compare only the emissions from our homes.

The specific emissions factors for housing are given here: the carbon footprint of my home

Average emissions from food in France per capita

Without being able to break down the 81.2 million tons from agriculture precisely by foodstuff, and considering that all our food necessarily comes from this agricultural production (the case of imports/exports being excluded by the UNFCCC convention), we could estimate that we emit an average of 1.20 tons of CO2 per inhabitant at national level (81.2/67.626396 ).

However, as we explained in a paragraph above, we prefer to use the ADEME data and CO2 methodology to calculate our food carbon footprint.

Thus ADEME estimates that a French person consumes on average the following rations (all figures and references are explained on the Github page mentioned at the top of this article):

- Red meat 110.1 g/day

- White meat 52.9 g/day

- Fish/shellfish: 80.9 g/day

- Exotic fruits/vegetables: 135.2 g/day

- Local fruit/vegetables 222.7 g/day

- Dairy 3.5 g/day

- Rice/Pasta 137.9 g/day

- Bread (all types): 155.8 g/day

- Alcohol: 227.5 g/day

- Fruit juice/soda/water 783.2 g/day.

Using the specific emissions factors for food available here: the carbon footprint of my food.

We arrive at the value of 2,563 kgCO2e / year and per person (addition of all these figures x 365).

We increase this figure by 4.86% to take into account the production of waste, i.e. 125 kg of CO2 per year per inhabitant. Here again, the ADEME figure differs slightly from that of CITEPA (3.5%), given the differences in calculation methodologies, but the orders of magnitude remain consistent.

Thus, in total, we emit an average of 2.69 tCO2/year per inhabitant for food.

Average emissions from air transport in France per capita

According to the DGAC (Direction Générale de l'Aviation Civile), which publishes an annual BULLETIN STATISTIQUE TRAFIC AERIEN COMMERCIAL, and based on figures provided by CITEPA, CO2 emissions from INTERNATIONAL commercial aviation in France in 2021 amounted to 8.8 million tons of CO2 for 49.73 million passengers. Domestic air traffic emits 3.3 million tons of CO2 for 20.33 million passengers.

By way of comparison, it is worth remembering the figures for 2019, before COVID: 179.6 million passengers and 23.4 million tCO2.... The 2021 traffic corresponds to about 39% of the 2019 traffic. This is the lockdown effect.

By design, these French data include all domestic flights and half of the international flights in order to avoid double counting.

This means that each passenger emits an average of 0.173tCO2 ((8.8+3.3)/(49.73+20.33)) per trip. With a French population of 67,626,396 inhabitants, the average French person makes 1.04 trips and emits an average of 0.18 tCO2.

And yes, contrary to popular belief, aviation is not the largest sector of emissions for the French! Hence the importance of focusing first on our homes and cars.

France's CO2 emissions for COP21 target

The Paris Agreement, signed in 2015 at COP21, is the new international climate agreement. For the record, its objective is to limit global warming to well below 2 degrees Celsius, preferably 1.5°C.

The 156 countries (out of 196) that have ratified the Paris Agreement have committed to producing their CO2 emission projections every five years (2015, 2020, etc.), known as INDCs in COP21 jargon. A single INDC for all 28 European Member States has been submitted, France did not have to submit a national INDC.

The COP21 is therefore reflected in France by the National Low Carbon Strategy law, also known as the SNBC.

This SNBC defines a trajectory for reducing greenhouse gas emissions up to 2050 and sets short- and medium-term targets.

The SNBC thus sets the CO2 emissions for France at 80 million tons of CO2 in 2050.

The National Low Carbon Strategy also foresees that the French land and oceans absorb 80 million tons of CO2, which would bring France to a net zero CO2 emissions per year in 2050. This objective is known as Carbon Neutrality in the SNBC.

This objective is independent of the French population. It is a target in absolute terms!

The French population in 2050 is unknown, and probably growing compared to the population on 1 January 2020. By dividing the 80 million CO2 emissions by the current population, we obtain a maximum of 1.19 tons of CO2 per person! If the population grows, this target will be even smaller for each of us.

For the four sectors of interest to us, the SNBC foresees a complete decarbonisation for transport and housing. For 2050, the SNBC also foresees a 46% decrease in emissions from agriculture compared to 2015 (87.37 million tCO2), i.e. 47.18 tCO2.

Thus, by keeping 3.5% of waste, the COP21 target per French person is reduced to 0.73 tons of CO2 (47.18/67.064+3.5%) in 2050.

What is a carbon champion?

We call those people who already emit no more CO2 today for their housing and transport "carbon champions". Their carbon footprint is very low. It is in fact already technically possible by heating with wood or a heat pump, and by travelling by train, public transport, electric car and bicycle.

In these sectors, they are already on target for COP21. They are proving that it is possible to live happily without emitting CO2 and without showering with cold water or curdling in winter in an unheated home lit by candlelight.......

These champions are human and eat like everyone else.

Given the precision of the calculation on food explained above, we have arbitrarily decided, based on the calculation of the emissions of different diets, to set the threshold of their emissions at 50% of the current national average, i.e. 1.34 tons of CO2.

This means that the champions have a CO2 footprint that is already close to the COP21 target. Bravo, bravo, they are true champions.