Main questions and answers

Because this foresight exercise is complex and the working hypotheses are numerous, ADEME has included in this FAQ some answers to the major questions that may arise.
This FAQ will be regularly updated.

What is the definition of Carbon Neutrality and within what boundaries is it calculated for this exercise?

*** The Climate Neutrality Target

The carbon neutrality target results in a balance between greenhouse gases emitted each year and the amount of CO2 absorbed by carbon sinks within a national region. Sinks can be natural (forests and soils) or technological (carbon capture and sequestration at industrial sites or by removing carbon from the air). Current total emissions in France are approximately 436 Mt CO2/year (2019). French sinks (exclusively natural, soils and forests up to 2020) are about 30 Mt CO2/year. Achieving the target therefore means reducing annual emissions by 406 Mt CO2/year while maintaining the existing level of carbon sinks or being able to increase the capacity of sinks for a higher residual emissions allowance.

The French Energy and Climate Act [1] set the target of a minimum six-fold reduction in gross greenhouse gas emissions by 2050 compared to 1990, which also implies being able to almost double the capacity of sinks at the same time. Implications for energy planning over the next 10 years, which was defined in 2020 in the multi-annual energy programme [2]. The planning was defined to be consistent with the longer-term line of action of the SNBC (Stratégie Nationale Bas Carbone - French national low-carbon strategy), namely the challenge of completely decarbonising the energy sector by 2050, by replacing fossil-fuel energies with energy that does not emit greenhouse gases, and developing carbon sinks to offset unavoidable emissions. There are, however, other greenhouse gas emissions not related to energy production that also need to be offset. The SNBC [3] estimates the energy needs of half of the consumption by international transport (aircraft or shipping to external destinations), but not the associated emissions.

Achieving the carbon neutrality target is therefore very ambitious but also offers room for manoeuvre to define different strategies and transformations of the French development model. Each of the four ADEME scenarios explores different transformations that affect the nature and level of emission reductions, residual emissions and development of carbon sinks. Therefore they explore strategic alternatives on the nature and content of the ecological transition with a view to achieving the same level of contribution to climate change.

Therefore, the theoretical definition of net zero or negative emissions (Objective Net Zero) is used as the target for the four carbon neutrality scenarios, rather than the policy direction planned today (a six-fold reduction in emissions). In addition, the scenarios reach a climate neutrality target that covers all major greenhouse gases and not just CO2 (including methane, nitrous oxide and fluorinated gases). The contribution to warming of these various gases is converted into tonnes of CO2 equivalent in accordance with applicable conventions [1]. The net emissions balance is therefore expressed as tCO2eq (positive emissions minus negative emissions from sinks for all gases). The reference to “carbon neutrality” must therefore be understood in this sense, as an extension of language.

[1] Energy and Climate Act (2019). Law No. 2019-1147 of 8 November 2019 on energy and climate. Legifrance. https://www.legifrance.gouv.fr/loda/id/JORFTEXT000039355955/

[2] Multi-annual energy programme (2020). Decree No. 2020-456 of 21 April 2020 on multi-annual energy programming. Legifrance. https://www.legifrance.gouv.fr/loda/id/JORFTEXT000041814432/

SNBC [3] (2020). Decree No. 2020-457 of 21 April 2020 on national carbon budgets and the French national low-carbon strategy (SNBC 2). Légifrance. https://www.legifrance.gouv.fr/jorf/id/JORFTEXT000041814459/


*** Territorial scope, emissions accounting. 

Carbon neutrality is calculated within the boundaries of mainland France. The SNBC scenario covers the scope of the Kyoto Protocol inventory (mainland and French overseas departments). The multi-annual energy programme only concerns mainland France, since the regions that are not part of the mainland have their own specific energy programming laws. This implies conventions that are not always simple where transport consumption in the French Overseas Territories is included, but the electrical systems of the French Overseas Territories are excluded. When comparisons are made with the SNBC scenario, only mainland France is included unless stated otherwise. 

International bunker fuel (consumption by aircraft and shipping operating international routes) is expressed but is not currently taken into account in the carbon neutrality calculation. This could change in future versions of the SNBC.

Is a carbon footprint calculation performed?

In a future publication, we will give an estimate of emissions generated by French consumption (its ecological footprint), which measures the impact of French society in addition to our national emissions alone. The footprint includes emissions in foreign countries generated to produce products imported into France and subtracted from our national emissions due to our exports. This assessment will cover the material footprint, greenhouse gases, resources and consumer goods.

What GHG sinks are mobilised in this exercise?

In the ADEME Transitions 2050 scenarios, two types of sinks are considered:

* Natural sinks that incorporate the impact of changes affecting soils, agricultural practices and forestry management on carbon stocks in soils and biomass (plants, wood products etc.).

* So called “technological sinks” related to geological carbon capture and storage technologies (BECCS, DACCS).

CCS (Carbon Capture & Storage) technologies have been considered as a technology for reducing industrial emissions rather than a sink per se.

On the other hand, the following are considered to be technological sinks:

- Use of CCS on power plants running on biomass (biorefineries or wood cogeneration), BECCS (bioenergy with CCS);

- Necessary use of atmospheric CCS (DACCS - Direct Air CCS).

No anthropogenic levers for increasing sinks in marine and coastal environments could be considered in the absence of national references.

Mineral materials capable of sequestering CO2 (excluding wood products), bio-based products and soil amendments (biochars, silicates) were not included because of a lack of data and studies to assess their potential in France.

Depending on the scenario, changes in carbon stocks in different reservoirs and the level of sinks largely depend on land use choices, the intensity of biomass harvesting and biomass uses: keeping it in the environment and returning it to the soil, food and animal feed, materials, energy, technological capture and storage of CO2.

The relative importance of different sinks in scenarios, in particular natural sinks and BECCS, therefore depends closely on the assumptions made about food and non-food biomass requirements.

Is the impact of climate change taken into account in the assessment of sinks?

In this exercise, we took into account the impact of climate change on forest ecosystems (and therefore on BECCS), using scenarios developed by INRA and IGN for RCP 8.5 climate change. The effect of the RPC 8.5 climate scenario can be summarised as a general slowdown in growth and a sharp increase in mortality, thus limiting the carbon sinks required in the 2050 time frame without eliminating them. The models do not take into account an increase in the occurrence or intensity of biotic events (insects and pathogens) and abiotic events (drought, frost, storm, fire), which could also limit carbon accumulation in forest ecosystems.

Are the 4 scenarios realistic?

Modelling is by necessity theoretical: any model is by definition a simplification of reality. The models used in this exercise have varying degrees of accuracy, without it being possible to quantify the margins of uncertainty associated with the modelling results. The results presented here must therefore be considered as orders of magnitude. In this exercise, ADEME proposes several archetypal scenarios, which present, in a deliberately contrasting manner, economic, technical and societal options for achieving carbon neutrality, without covering the whole range of possible futures that could be decided upon.

However, each of the four paths presented by ADEME to achieve France's carbon neutrality in 2050 has its own internal consistency, for the sake of realism.

Is the COVID-19 crisis taken into account?

This scenario modelling was published during a very particular period of time, affected by the COVID-19 crisis which created a one-off break with the trend, making 2020 a record year of decline; however, the rebound in emissions is already being seen.

This period has affected people’s mental outlook, such as certainties about future continuation of the major trends of the past, the possibilities of a break with those trends, possibilities for action and changes in collective values. Discussions are being held to assess whether the “world after” will still be like the “world of yesterday”. This possibility of sudden change is not taken into account in the construction of carbon neutrality scenarios. It does not change the view of the long-term physical transformations that will be needed to reduce emissions and absorb greenhouse gases. However, this train of thought will be kept as a backdrop to ask whether the long-term developments described are being held back or promoted by this context of disruption (e.g., increased teleworking that will affect travel and transportation emissions), whether this context changes the assessment of one strategy over another (e.g., because it accelerates certain reassessments and awareness of changes that are perceived as more feasible and desirable after the pandemic). Nevertheless, the Covid 19 context forms a backdrop to reading the scenarios much more than it was involved in generating them.

Does the trend scenario take the measures of France Relance into account?

The trend scenario was created before France Relance was set up. It would be possible to assess in a future revision how far this plan contributes to bringing us closer to the trajectories of the carbon neutrality scenarios.

To what extent are the scenarios for France dependent on the strategies adopted by neighbouring countries?

This is an important question (the international context, particularly in Europe). We approach it at the level of sector-based assumptions by describing assumptions regarding changes in external trade (industry, agriculture, etc.). The multi-sector macro-economic model ThreeME describes the external trade of the main branches of the French economy. The sector chapters also specify whether political developments at European and international level are conditions for success. In this case, these will be factors affecting France's “external policy" strategy, which must be pursued at the same time as the national strategy.

Why is a single long-term potential growth rate considered for all scenarios?

Changes in the economic context are described specifically in the sector-based and macroeconomic analyses. These analyses identify economic conditions consistent with the transformations described in each of the scenarios. They also examine the economic consequences of these changes (investment requirements, effects on economic activity and employment, production costs and incomes, economic policies, and so forth). 

To provide a comparison of the shocks represented by the carbon neutrality scenarios with respect to a common reference base, common assumptions are used for potential productivity growth (*) and growth in economic activity (material and immaterial activities), as well as assumptions on trends in price changes of imported fossil fuel energies, which determine the incentive to reduce the use of these energies. These developments are highly uncertain and debated. To facilitate comparisons with official scenarios, we have used the Recommendations to the States of the European Commission for fossil-fuel prices and the long-term potential growth assumptions of the SNBC AMS scenario. This productivity growth assumption is a high assumption given the trend for this to slow down since the 1980s and macroeconomic work that has highlighted the possibility of “secular stagnation” since the late 1990s. But it has the merit of making us consider situations where the level of emissions may be increased by a growth in economic activity. The technical and macroeconomic analysis will therefore reveal changes in the material content of future economic activities which is needed to achieve the objectives while still considering economic development. These analyses will feed into the discussion on the possibility of decoupling future economic activity from pressure on resources, climate and ecosystems and will encourage thought on the precise nature of the reorientation of economic activity.


(*) Potential growth differs from realised growth. The long-term growth potential is estimated based on assumptions about changes in the labour force and assumptions about changes in average worker productivity. The growth achieved differs from this potential due to many sources of inefficiency: unemployment, lack of productive capital, infrastructure, inefficiencies in collective organisation, wealth distribution, availability of raw materials, etc. The potential growth assumption is therefore the same for all scenarios, since today there are no robust studies on the comparative effects of low-carbon strategies on potential growth. However, macroeconomic analyses performed by ADEME can be used to estimate the effect of ecological transition scenarios on growth and employment (see forthcoming macroeconomic analysis).

Are employment consequences analysed?

An analysis of the effects on employment at the macroeconomic level using the ThreeME model will soon be published (taking into account the effects of wage adjustment in terms of unemployment, price-wage relationship, level of activity and demand, etc.). 

At a finer level, information will also be available in the sector specific forward looking studies (Proteins, New Construction, Logistics, Gas and Liquid Fuels). In the sector forecasts, employment is covered in the assessment of the current situation and then in the 2020-2030-2050 trajectories towards carbon neutrality. We do not use a model but available statistical data and expert statements (ADEME and stakeholders).

 Finally, some studies that focus on a particular region address a particular theme at regional level and give rise to an evaluation of employment associated with the strategies (e.g. in the “Hauts de France” region (northern-most part of France).


Do demographic changes vary between scenarios? What are the assumptions used and do they address the issue of migratory movements?

The demographic assumptions follow the low-level INSEE forecast scenario, which best reflects the current trajectory and the observed decline in fertility. Demographic changes also take into account changes in the age pyramid with the continuing ageing of the French population. It also includes assumptions on the migratory balance that take into account observed long-term trends and which is stabilised at the level observed over the period 2000-2010. The forecast does not include unobserved and more uncertain major changes that could occur under particular geopolitical and climatic assumptions.

Does the study presented on lifestyles seek to be statistically representative?

No, the study presented on lifestyles does not try to be statistically representative. However, the 31 individual interviews conducted have a wide variety of socio-demographic characteristics.

The study produced results specific to each scenario, enabling constraints to be explored as well as perceived benefits from the perspective of a range of citizens. It is also used transversely for the four scenarios. It has enabled various conditions and points of tension to be identified, which are all points to be watched when building the transition to 2050. These lessons are of particular relevance to public policy, as they outline various conditions affecting the feasibility and desirability of the four scenarios. They are also of interest to the targets of ADEME, whether they are the public, decision-makers or public and private organisations, since they all participate in the effort to look forward and make decisions to undertake the ecological transition.

Do Transitions 2050 scenarios explore the implications for biodiversity and water resources?

No accurate figures on impacts on biodiversity and ecosystems could be produced, in particular due to the lack of geographical localisation of the scenarios. Discussions are however underway with the French Office for Biodiversity at time of writing of this report. Similarly the question of water use and impacts on water resources and aquatic environments could not be studied in depth (apart from water requirements for agricultural irrigation). Nevertheless, discussions have been initiated with the Water Agencies to further explore this strategic issue.

What do the final energy demand categories by fuel include in our infographics?

The final energy consumption mix has been thoroughly analyzed in this prospective study.

In order to simplify the representation, especially in the infographics by scenario, we had to group them by major categories:

  • Electricity
  • Heat: the term Heat here refers to the sum of district heating and renewable off-grid heating energies, which include solid biomass / biofuels / biogas in direct use / waste / solar thermal / heat pumps.
  • Gas: fossil gas and network biogas
  • Liquid fuels: liquid fossil fuels
  • H2: hydrogen
  • Others: mainly coal