08.12.2025

Unless we rapidly ramp up CO₂ removal, climate neutrality by 2045 will be scarcely achievable, scientists say

Interdisciplinary research project including Tübingen researchers gives recom-mendation for removing CO2 from the atmosphere

According to the Federal Climate Change Act, Germany is supposed to achieve green-house gas neutrality by 2045. To do this, it is not sufficient to massively reduce emissions: A significant portion of CO₂ needs to be removed from the atmosphere as well. Over 100 scientists in the large-scale interdisciplinary program CDRterra, working in ten research projects, have investigated various carbon dioxide removal (CDR) methods – from biological to (geo-)chemical techniques. One of these projects is headed by University of Tübingen scientists, Professor Kira Rehfeld (Department of Geoscience) and Dr. Matthias May (Department of Chemistry). The team led by the two researchers is developing a process for removing carbon dioxide from the atmosphere and converting the carbon it contains into products that can be stored long-term using artificial photosynthesis. The group, which also includes scientists from the Helmholtz Center Berlin, the Karlsruhe Institute of Technology, the Technical University of Darmstadt, and the Universities of Stuttgart and Ulm, operates under the name NETPEC, short for Negative Emission Technologies based on PhotoElectroChemical methods. Funded by the Federal Ministry of Research, Technology and Space (BMFTR), the CDRterra program is coordinated by LMU Munich.

Our CO₂ removal efforts must accelerate

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

Today, however, Germany removes just a fraction of this amount from the atmosphere. Even with extremely ambitious reductions, some 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.

Established methods require new laws

Proven methods such as afforestation, reforestation, agroforestry, and carbon farming techniques like cover cropping can be implemented in the short term and accelerate the sequestration of carbon dioxide. Modeling shows that large-scale afforestation and reforestation programs 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 areas. In addition, there are legal and structural barriers: For example, the conversion of grassland into forest is prohibited in many places, and farmers often lack the know-how and long-term planning certainty.

Innovative CDR methods with potential

To expand the portfolio, the researchers have investigated novel techniques. They see potential, for example, in artificial photosynthesis, which uses solar energy to convert carbon dioxide into carbon flakes – and is more efficient than natural processes. Novel CO2-sequestering building materials based on gabbro, biochar, and bio-based carbon fibers are also promising. However, these options need more time to be developed.

NETPEC’s Kira Rehfeld explains: “Our project seeks to develop an efficient artificial photosynthesis of low-energy, carbon-rich molecules in order to store them as solid or liquid substances close to the Earth's surface.” This process could offer particular ad-vantages for regions where CO2 cannot be compressed into gas form or transported away, Rehfeld adds.

"Artificial photosynthesis enables society to reduce long-term climate and environmental impact by CO2 extraction achieved through efficient land use and energy self- sufficiency. However, further research is needed to develop prototypes from the initial results and for us to conduct large-scale field tests," says Matthias May.

Society and infrastructure as key factors

Carbon dioxide removal is also a technical challenge which requires good planning of 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 when it comes to implementation,” emphasizes LMU geographer Dr. Felix Havermann, scientific coordinator at CDRterra.

The conclusion of CDRterra is unambiguous: In order to achieve greenhouse gas neu-trality, land use and agriculture have to be fundamentally reformed, suitable infrastructure needs to be developed, and the right political frameworks need to be created – in close dialog with society. This will also allow a wide variety of ecological and social benefits to be leveraged. The CDRterra scientists emphasize: “We’ve got no more time to lose – the next few years are decisive.”

Further information

CDRterra website
Download of research results and recommendations
NETPEC project website
Webpage of Kira Rehfeld’s Climatology working group
Webpage of Matthias May’s Electrochemical Spectroscopy working group
Article on Tübingen research on aritificial photosynthesis (attempto! research magazine 58, 2023)