Meeting our energy needs while reducing our carbon dioxide emissions.

Gas, coal, and oil still account for 80% of the energy used by industrialized nations. But this excessive consumption has its limits, and simply sparing the energy we use will not be enough to stop climate change. The challenge is to understand how we can ensure our energy needs are met while making the transition to tomorrow's energy. Rethinking our energy future is urgent, something that should not be based on ideological convictions or political choices, but on orders of magnitude and matters of physics. One thing is for sure: if we are to succeed in doing away with fossil fuels and setting up new energy systems, our entire way of life must be reinvented.