The term decarbonization has flourished since the G7 summit at Schloss Elmau in 2015, at which the world’s seven largest economies decided that the entire economy should be completely CO₂-neutral by 2100. The overarching goal is to stop climate change and thus limit global warming to below 2°C. The term decarbonization is used to describe this process.
The term decarbonization contains the word carbon. Decarbonization therefore refers to the shift away from carbon, especially in the energy sector but also in the economy in general. The burning of fossil fuels such as oil or natural gas releases large amounts of CO₂ into the earth’s atmosphere. Since CO₂ absorbs thermal radiation extremely well (especially the radiation emitted from the Earth, as this is in the range 13 µm - 17µm, where CO₂ has the strongest adsorption), it actively contributes to global temperature rise.
Based on this knowledge, it is now necessary to significantly reduce CO₂ emissions and to produce the required energy in a CO₂-neutral way.
This connection is strikingly summarised in the term decarbonization.
Main CO₂ emitters
In Germany, energy production is the first CO₂ emitter, as can be seen from the fact that in 2020 the share of renewable, and thus CO₂-neutral, energies was 27% of total energy production (source). Most of the electrical energy is generated by conventional, fossil fuels. In Germany, lignite has the largest share with about 17%, followed by natural gas with about 12%. Nuclear energy is the second largest energy source. Despite the fact that no CO₂ is released during the generation of energy by means of nuclear power, the view that “nuclear energy is good because it is CO₂-neutral” would be dangerously short-sighted. The radioactive legacy of this type of energy production is no less dangerous.
Second place goes to industry and there especially the heavy industrial sectors of steel and iron - industry (35.6%) as well as refineries (23.2%) and cement plants (20%) (source / figures from 2019). These sectors are still dependent on fossil fuels and are only slowly moving to CO₂-neutral energy sources. Particularly in these sectors, the use of storage systems enables significant, rapid and cost-efficient savings of primary energy sources, and therefore a reduction of CO₂ emissions. Keyword: process heat recycling / buffer storage (for renewable energies).
Third place is taken by transport with 18%. This is divided into road passenger transport with 11% and road freight transport with 6% (source / figures from 2017). In this area, CO₂ can only be effectively saved by reducing traffic. Electrification has an effect on the CO₂ emissions of transport itself, but raises more strongly the question of the CO₂ production balance of the vehicles (keyword: battery production for e-cars). Here, a balance must be struck between necessary individual transport and sensible local public transport. For industry, a shift of freight transport from road to rail would be desirable. However, these two aspects must be politically initiated and promoted.
Rank 4 is occupied by the building industry as a whole. This refers to emissions caused by the operation of buildings. This includes private households as well as trade, commerce and services.
5th place is taken by agriculture because of its lower CO₂ emissions. Unfortunately, this is not due to ecological reasons, but results from the fact that in agriculture the emission of methane is significantly higher than that of CO₂. Methane is a much stronger greenhouse gas than CO₂, which is due to the fact that methane decomposes faster than CO₂, in about 12 years (methane) instead of 120 years (CO₂), but it is about 25 times more effective as a greenhouse gas.