According to the amended Climate Protection Act, Germany is to become climate neutral by 2045 – net emissions of greenhouse gases must reach net zero by then. But how? A team of more than 50 researchers has now determined which specific measures would be necessary by then in a comparative model simulation. This results in considerable discrepancies between the goals and the one planned so far.
According to the current climate protection law, Germany wants to become climate neutral by 2045 and reduce net emissions to zero. Specifically, this means that greenhouse gas emissions from various sectors, from electricity generation to industry, buildings, transport and agriculture must be greatly reduced, while unavoidable emissions must be achieved
Greenhouse gas sinks are offset. In order to achieve this, the Climate Protection Act sets the concrete interim goal of reducing greenhouse gas emissions by at least 65 percent compared to 1990 levels for 2030.
Setting the course by 2030
But how do you get there? So far, only the climate targets have been clearly formulated in the Climate Protection Act. But how the structural change towards climate neutrality in 2045 can succeed across all sectors remains to be seen. This is where the Ariadne Copernicus project, funded by the Federal Ministry of Education and Research (BMBF), comes in. In it, 50 researchers from ten institutions present a comprehensive model comparison that presents robust findings on transformation paths, leeway and bottlenecks in detail. From the overall system to individual sectors, from direct electrification to hydrogen and e-fuels to energy imports: Ten different models were integrated for the study and six different scenarios were calculated.
The main result: In order to make Germany climate neutral in less than 25 years, the next federal government has to get a lot going very quickly. “Climate neutrality cannot be achieved overnight, which is why important decisions have to be made at the beginning of the next legislative period,” explains Gunnar Luderer, co-head of the Ariadne project from the Potsdam Institute for Climate Impact Research PIK. “There is hardly any short-term leeway to get things going in a few years – above all a massively accelerated expansion of wind and solar energy.” According to the calculations, electricity generation from wind and sun should be around 50 percent by 2030 contribute more energy than previously targeted. The coal phase-out should take place as early as 2030.
What is needed in industry and buildings
However, it could be much more difficult to achieve the sector targets for industry, buildings and transport. Because they are characterized by long-lasting infrastructures, building or vehicle stocks and industrial plants. “If fossil fuels and raw materials are still the focus of steel or chemical production, for example, electricity and hydrogen will be the most important energy sources for industry in the future on a climate-neutral course,” says Andrea Herbst from the Fraunhofer Institute for Systems and Innovation Research ISI. “The time horizon until 2030 is decisive, because during this period, CO2-neutral processes must be scaled from the pilot and demonstration scale to an industrial level and operated economically”.
According to the study, there is still a lot to be improved in the area of buildings: “In order to bring the building sector on track towards climate neutrality, the model comparison shows the need for a consistent change in energy sources and an increase in the renovation rate and renovation depth,” explains Christoph Kost from the Fraunhofer Institute for Solar energy systems ISE. By 2030, the annual renovation rate would have to increase to 1.5 to two percent. Five million heat pumps would have to be installed and around 1.6 million buildings would have to be connected to the district heating network.
Problem child traffic
The transport sector shows the greatest discrepancy between transformation paths and sector goals. In order to achieve climate neutrality by 2045, electrification in passenger transport would have to be around 40 percent higher than previously targeted. Specifically, it would be necessary for at least 14 million electrically powered cars to be on our roads by 2030. But that alone will not be enough: “The short-term potential of the pure drive turnaround is limited by the long dwell times of the existing internal combustion engines. The sector targets for 2030 will not be achieved without additional measures. Among other things, changes in mobility behavior are required, such as switching to other modes of transport, ”explains Florian Koller from the Institute for Transport Research at the German Aerospace Center (DLR).
In the opinion of the scientists, in view of the major challenges in industry, buildings and traffic, it will be all the more important to act quickly and clearly, at least in the electricity sector. On the one hand, this ensures that enough electricity is available for electromobility, the production of hydrogen and the requirements of industrial production. On the other hand, an overachievement of the sector target of the energy industry could cushion the risk of missing the target in other sectors. “In politics, it is often still underestimated how far-reaching the necessary conversion to climate neutrality in 2045 will be,” says Luderer. “One thing is certain: if we fail to reach the milestone of the 2030 climate target, we will probably not be climate-neutral in 2045 either.”
Source: Potsdam Institute for Climate Impact Research, Ariadne Report 2021: Germany on the way to climate neutrality in 2045. Scenarios and paths in a model comparison.