‘Decarbonizing heat and transport’ describes methods for decarbonizing heat and transport. Using renewable electricity directly to produce heat, as in an electric oven, is currently more expensive than burning gas, or other fossil fuels, to generate heat. Capturing the carbon dioxide emissions from existing industrial processes is difficult, and the chapter addresses the challenges of meeting the large heat demand with renewable electricity, particularly for industrial processes that require high temperatures, such as in the manufacture of steel and cement. There, using electricity to produce combustible fuels (power-to-gas), such as hydrogen, could be effective. For heating buildings, electrically driven heat pumps are promising. Transportation also presents challenges. While the performance of electric cars is good, currently the main hurdle to switching is their cost. However, battery costs are falling fast, and new and traditional car manufacturers are already investing a considerable amount of money in developing electric cars. For heavy transport, fuel cells and power from ammonia are being considered.