The problem of massive emissions of carbon dioxide (CO2) from the burning of fossil fuels and their climatic impact have become major scientific and political issues. Future stabilization of the atmospheric CO2 content requires a drastic decrease of CO2 emissions worldwide. Energy savings and carbon sequestration, including CO2 capture/storage and enhancement of natural carbon sinks, can be highly beneficial, although it is suggested that both economic and climatic feedbacks could nullify part of the gains achieved. Fossil fuels (coupled with CO2 capture), and lower-carbon hydrogenated fuels such as natural gas are still expected to play an important role in the future. Nevertheless, stabilizing atmospheric CO2 concentration in a growing world economy, now dependent on fossil fuels for 85% of its energy, will also require a vast increase in the supply of carbon-free power. Among these energy sources, hydropower and nuclear energy (operated under western safety and environmental standards) are the most readily available sources capable of supplying vast amount of energy at a competitive price. Wind power is also to be encouraged, as it is expected to approach the competitiveness threshold soon. The French example, where fossil fuel CO2 emissions were cut by 27% in a matter of a few years (1979-1986) despite increasing energy consumption, suggests that implementing CO2 stabilization is technically feasible at a competitive price.