CDRterra Research ProjectClimate-neutral by 2045? Only with large-scale CO₂ removal

9 December 2025, by CDRterra/Thomas Merten

Photo: Thomas Wasilewski/Climeworks

A selection of land-based CO₂ sinks and removal methods (clockwise): afforestation, direct air capture, restored peatlands, soil carbon storage in agriculture.

According to the Federal Climate Change Act, Germany is supposed to achieve greenhouse gas neutrality by 2045. To do this, it is not sufficient to massively reduce emissions: A significant portion of CO₂ must also be removed from the atmosphere. Over 100 scientists – including researchers from the Earth and Society Research Hub (ESRAH) and the Cluster of Excellence Climate, Climatic Change, and Society (CLICCS) at the University of Hamburg – have investigated various carbon dioxide removal (CDR) methods in ten research projects, ranging from biological to (geo-)chemical techniques. The large-scale program, called CDRterra, is funded by the Federal Ministry of Research, Technology and Space and coordinated by LMU Munich.

Large-scale CO₂ removal is possible

The researchers are devising a scenario with ambitious measures. This foresees the sequestration of up to 80 million metric tons of CO₂ equivalent per year as of 2045 through various CDR methods – comparable to the annual emissions of Austria – if existing and new approaches are combined.

Today, however, Germany removes only a fraction of this amount from the atmosphere. Even with extremely ambitious emissions reductions, 60 to 130 million metric tons of residual emissions per year will remain from 2045, according to estimates. “Without ambitious emissions reductions and CO₂ removal, we will miss our climate targets. To ramp up CDR, we need clear rules, the build-out of new methods, the protection of natural sinks – and dialog with society,” says Julia Pongratz, CDRterra spokesperson and professor at LMU.

A doubling is necessary

Proven methods such as afforestation, agroforestry, and carbon-farming techniques like cover cropping can be implemented quickly and accelerate carbon sequestration. Modeling shows that large-scale afforestation can measurably slow climate change. But to limit global warming to 1.5 degrees, current global levels of CO₂ removal must be at least doubled by 2050. In Germany, this significantly intensifies competition for land. Additional legal and structural barriers remain: for example, converting grassland into forest is prohibited in many regions, and farmers often lack the know-how or long-term planning certainty.

Björn Maier/CDRterra

Innovative methods with potential

To expand the portfolio, the researchers have also examined novel approaches. They see potential, for example, in artificial photosynthesis, which uses solar energy to convert CO₂ into carbon flakes – more efficiently than natural processes. Promising options also include new building materials based on gabbro, biochar, and bio-based carbon fibers that can store CO₂. However, these approaches still require development time.

“No more time to lose”

CO₂ removal is also a technical challenge that requires well-planned infrastructure for CO₂ transport and storage. “Moreover, it’s a task for society as a whole. Farmers, industry, local authorities, and citizens need to be involved from the beginning – only this engagement can create the acceptance and trust that are decisive for implementation,” emphasizes LMU geographer Felix Havermann, scientific coordinator at CDRterra.

The conclusion of CDRterra is clear: To reach greenhouse gas neutrality, land use and agriculture must be fundamentally reformed, suitable infrastructure must be built, and the political framework must be established – in close dialog with society. This would also unlock a wide range of ecological and social benefits. The research consortium emphasizes: “We’ve got no more time to lose – the next few years are decisive.”