Nuclear power is often suggested as a ‘cleaner’ or ‘greener’ alternative to power production using fossil fuels such as coal and oil. Nuclear power may be less air-polluting than fossil fuels, but it still poses an unacceptable risk to the environment and to humanity. The expansion of all nuclear power production should therefore be stopped and existing plants shut down. Despite what the nuclear industry tells us, building enough nuclear power stations to make a meaningful reduction in greenhouse gas emissions would create tens of thousands of tons of lethal, high-level radioactive waste. Instead, we need an energy system that can fight climate change, based on a mix of renewable energy sources (such as wind, solar and tidal) and energy efficiency. Nuclear power already delivers less energy globally than renewable energy.