[en] In France and in Europe, the political vision of energy production has not yet been taken to heart as much as its importance merits, despite a certain awareness of the gravity of the phenomena within the population. It would already be very difficult to halve the consumption of fossil fuels in France in 2050, without a swift and profound change in our energy-consumption choices (in particular in transport) and a considerable research effort. To divide it by four seems unrealistic, since France, unlike other countries, has already benefited from the transition from electricity produced from fossil fuels to nuclear electricity which does not emit CO₂. A major evolution in energy, in Europe and throughout the World, is inevitable in the course of the century. To prevent this from being too violent and painful, a process of fundamental research and technological development should be launched forthwith, in all fields of energy production, storage and use, with a large effort supported by major research programmes. Some recommendations are given for the main research fields that should be: capture and long term storage of CO₂, energy savings in transport, energy supply to large cities and nuclear power plant enhancement, hydrogen storage, wind energy and its unavailability problem, use of forest resources, photovoltaic electricity in rural and isolated regions, temporary storage of electricity