Around the world, the energy sector accounts for a large share of CO2 emissions, despite a downward trend. The main sources of energy in Germany, as in other countries, are lignite and hard coal-fired power plants, which emit an average of up to 800g of CO2 per kWh.

When electricity is generated from nuclear energy, no climate-damaging emissions are released during operation. However, related activities, such as mining of the raw material uranium and the construction and dismantling of power plants, can still release emissions. If these emissions are included, a nuclear power plant emits an average of about 12g CO2 per kWh, much less than a coal-fired power plant. Thus, an increase in the share of nuclear power can make the electricity mix more CO2-neutral in the short term. In the International Energy Agency (IEA) scenario on which the Paris Score is based, nuclear power is therefore part of the transformation of the electricity sector. However, this does not take into account problems of nuclear waste storage.