Transition(s) 2050: 4 scenarios to achieve CO2 neutrality

This unprecedented forecasting exercise is based on two years of development work, the mobilization of about a hundred ADEME employees and regular exchanges with a scientific committee and external partners and service providers, specialists in the various fields.

The 4 scenarios

They are designed for metropolitan France and are based on the same macroeconomic demographic and climate change data (+2.1°C in 2100). They all lead to carbon neutrality of the country, but follow different paths and correspond to different social choices.


Significant changes in the ways of moving, heating, eating, buying and using equipment make it possible to achieve carbon neutrality without using carbon capture and storage technologies, which are unproven and widely uncertain.

New consumer expectations, but especially new practices, are quickly expressed in consumption patterns. The growth in energy demand that depletes resources and degrades the environment is interrupted by behavioral, organizational and technological innovations. The transition is mainly driven by frugality, restraint and frugality.

Discover in detail the scenario Frugal Generation


Society is changing under shared governance and territorial cooperation. Non-governmental organisations, public institutions, the private sector and civil society are finding ways of pragmatic cooperation that help maintain social cohesion.

To achieve carbon neutrality, the company relies on a gradual but steady evolution of the economic system towards a sustainable path that combines frugality and efficiency. The consumption of goods is measured and accounted for, sharing becomes widespread.

Discover in detail the Territorial Cooperation scenario


It is technological development that makes it possible to respond to environmental challenges rather than behavioral changes in the direction of more sobriety.

Metropolises are growing. Technologies and digital, which enable energy or material efficiency, are present in all sectors. The best technologies are widely deployed and widely available to creditworthy populations.

Discover in detail the Green technologies scenario


The lifestyles of the early 21st century are guaranteed. But the proliferation of goods consumes a lot of energy and materials with potentially strong environmental consequences.

Society relies on the ability to manage and even repair social and environmental systems with increased material and financial resources to sustain a livable world. This exclusive support for technologies is a gamble insofar as some of them are not mature.

Discover in detail the Healing Bet scenario}

Understand the 4 scenarios in 4 minutes and in video

9 lessons for a CO2-neutral future

  1. The four paths presented, each with its own consistency, will enable France to achieve carbon neutrality by 2050. But all are difficult and require orchestrated planning of transformations involving the state, territories, economic players and citizens.
  2. Achieving neutrality is based on strong bets, both at the human level (behavioural changes) and at the technological level (especially carbon sinks). All scenarios therefore involve an element of risk. But not all of them have the same environmental, social and economic consequences.
  3. For all scenarios it is necessary to act quickly: the socio-technical transformations that need to be implemented are of such magnitude that they take time to produce their effects. It is necessary from this decade to undertake the planning and profound transformation of the modes of consumption, the development of the territory, the technologies and the productive investments.
  4. Reducing energy demand, which is itself linked to demand for goods and services, is the most important factor in achieving carbon neutrality. This reduction can vary from 23% to 55% compared to 2015, depending on the scenarios, each based on a different balance between sobriety and energy efficiency.
  5. The industry will need to transform not only to adapt to a rapidly changing demand, but also to decarbonise its production. This requires large-scale investment plans and an effort by all of society to support changing areas and train workers in new professions.
  6. Living organisms are one of the main assets of this transition, making it possible to combine three strategic levers: carbon storage, biomass production and greenhouse gas reduction. It is therefore essential to maintain a balance between the food and energy use of biomass while preserving ecological functions, such as biodiversity and carbon storage, thanks to a global approach to the bioeconomy.
  7. The adaptation of forests and agriculture is therefore becoming an absolute priority in the fight against climate change. The resilience of ecosystems is all the more important as they are increasingly subject to the impacts.
  8. The pressure on natural resources varies considerably from scenario to scenario. This is especially the case for irrigation water or building materials, whose volumes consumed vary by a factor of 2 between certain scenarios.
  9. In all scenarios, more than 70% of the energy supply will be based on renewable energy sources by 2050 and electricity will be the main energy carrier. However, this cannot in any way legitimize the waste of energy, to limit the pressure on resources.


5 issues to discuss

Sobriety, carbon sinks, nutrition, construction economics, industrial model: whatever the choices of society, these 5 issues will have to be the subject of structuring debates.

  1. Sobriety: how far? : Decarbonising energy will become all the easier when demand is low. However, the reduction in this demand is determined by two factors: the sobriety approach and energy efficiency. The potential for energy efficiency is met with physical limits and especially those of available technologies, so there is no escaping a demand for sobriety.
  2. Can we rely solely on natural carbon sinks to achieve neutrality? : The four scenarios show that achieving CO2 neutrality is not possible without natural CO2 sinks (plants, soils and products) because their potential is very high compared to technological sinks (CO2 capture and storage).
  3. What is a sustainable diet? : In France, food accounts for a quarter of the carbon footprint and is at the crossroads of multiple health and environmental issues, most notably preserving biodiversity, water and soil quality.
  4. Artificialization, precariousness, renovation: is a different construction economy possible? : Residential and tertiary buildings now represent almost half of national energy consumption, almost a quarter of greenhouse gas emissions, consume 51 million tons of materials per year for their construction and participate directly in soil artificiality.
  5. Towards a new industrial model: is sobriety harmful to French industry? : It is now widely accepted that moving industry to France is vital for our economy and its resilience. However, this move is not self-evident in a globalized world and will not be without consequences. The competitiveness of the industry will be developed with two levers more or less activated depending on the scenarios

What you will find in the full report

For each scenario, ADEME constructed a coherent story, administered in each economic and social sector, through structuring variables. The description of the scenarios covers the sectors construction, passenger mobility and freight transport, food, agriculture, forestry, industry, waste and energy services (fossils, bioenergy, gas, hydrogen, heat and electricity).

The parameters examined relate in particular to: energy demand; consumption of irrigation water, building materials, agricultural inputs and land use; waste production and management; the production of energies and the composition of the energetic bouquet; import and export; the greenhouse gas balance and the biological and technological sinks of CO2.

Download the full report

Replays Transition(s) 2050. Choose now. Trade for the climate.

Special edition produced in collaboration with So Good

How will a CO2-neutral future shake up our lifestyle?

Project yourself into 2050 through four fictional reports inspired by the Transition(s) 2050 scenarios, and discover what these environments would look like. A story accessible to everyone, original, funny and inspiring, that encourages reflection on the consequences of climate change and the path(s) we can take.

Start by taking the test to find out which scenario suits you best, and finish with an educational glossary if you still have things to learn! Good reading.

Which adaptations of buildings in collaboration with the OID?

The real estate sector is already very exposed to the vagaries of the weather. How will this exhibition evolve in 2050? On the basis of which adaptation solutions could they be implemented and what would their ecological footprint be?

To answer these questions, the OID explores the exposure to four climatic hazards (heat wave/urban heat island, drought/shrinkage-swelling clay, flooding and submersion) of the housing stock in metropolitan France in the Transition Scenario(s) 2050 from ADEM. Find the executive summary and technical report explaining the methodology of this study.

What adaptation of buildings in ADEME’s Transition(s) scenarios?

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