The need to decarbonise the energy system and to slow down climate change is too urgent: we simply cannot afford to exclude any available or envisaged low-carbon technology from the portfolio. As the environmentalist James Lovelock put it a few years ago: "Now that we've made the earth sick it won't be cured by alternative Green remedies like wind turbines or biofuels, and this is why I recommend the appropriate medicine of nuclear energy as a part of a sensible portfolio of energy sources". All technologies can help, if they are developed and used with the twin goals of sustainability and safety kept in mind. It is unlikely that renewable technologies such as those exploiting the sun, wind or oceans as energy sources can completely replace fossil fuels within the next couple of decades. Moreover, the exclusive use of renewable energy would necessarily require the simultaneous implementation of new transmission and storage systems, which are very valuable technologies, but still under development and altogether very costly. In other words, achieving a low-carbon energy economy over the next couple of decades would be very difficult without nuclear energy acting as base-load, with renewables on top: the combination of nuclear and renewables will guarantee a strong energy system. Nuclear energy has the big advantage of being a low-carbon technology that already exists and guarantees high energy output (to produce as much electricity as nuclear plants currently produce in France, half of Belgium would need to be densely covered with wind turbines). Furthermore, nuclear produces energy at a constant rate and at stable, predictable and competitive prices.