“To achieve the 1.5°C target and mitigate climate change, negative emissions are becoming increasingly unavoidable. One of the options with which we can potentially achieve this is DACCS,” says Dr. Barbara Breitschopf, project manager at Fraunhofer ISI. Together with her team, she examined the possibilities and limitations of the process. To be more precise, DACCS refers to the technical extraction of CO₂ (Direct Air Capture, or DAC for short) from the atmosphere, its transport from the extraction point to the storage site, and the long-term and mostly underground storage of CO₂ (carbon storage, or DACCS together).

The role DACCS plays in the future will depend on how the processes develop technologically, the associated costs, and the extent to which the process is accepted by society. With regard to CO₂ storage in particular, acceptance cannot be taken for granted. In addition, the process needs to be embedded in the existing political framework. In the Policy Brief, Fraunhofer ISI experts explain the central questions surrounding the topic of DACCS, such as where DACCS stands in terms of application technology, how DACCS should be classified alongside other options for achieving negative emissions, and what the possible developments might be. They address societal impact, potential environmental effects, and the role DACCS should play in a climate strategy.

What is the environmental impact of DACCS?

Given the low natural CO₂ concentration in the air, the extraction of CO₂ is associated with very high energy use. Therefore, the locations for Direct Air Capture facilities should be chosen so that low-emission energy sources can be used. In Germany and internationally, these are not yet sufficiently available and would have to be established additionally, requiring resources and space.

Geological storage sites are currently considered the most viable option for CO₂ storage. There is extensive experience in this area, especially from the extraction of fossil raw materials, and the necessary technological requirements, such as for the feed-in process, are well known. 

Public debate

Previous attempts to store CO₂, for example in Germany or other EU countries, were often highly controversial in the regions concerned, and earlier surveys showed that larger groups of the population in Germany were critical of CO2 storage. There are no extensive up-to-date studies available. With regard to the removal of CO₂ the options that are more positively assessed are those that are perceived as “natural”, for example in the form of binding CO₂ in plants such as through reforestation, these methods are perceived as less “technical” or complex.

A broader public debate is therefore required for a target-oriented development of DACCS and a society lead decision on a deployment strategy. “The knowledge of many stakeholders in society about DACCS is still very limited. With our policy brief, we want to contribute to a public discourse on the use of DACCS as a technical option for achieving negative emissions,” Breitschopf explains.

What role should DACCS play in a climate protection strategy?

In many climate change mitigation scenarios, DACCS is seen as a possible option for offsetting CO₂ emissions in sectors that are difficult to decarbonize. In addition, it can also serve as a risk protection against possible failure to meet climate protection targets. The latter, however, harbors the associated risk that other necessary emission avoidance measures will be postponed and therefore transformation delayed.

As Fraunhofer ISI's comprehensive analysis has shown, DACCS is currently one of the more promising technological approaches to achieve negative emissions, even though its deployment is still associated with many open technical, regulatory, economic, environmental, and societal issues and challenges.

In this respect, the Fraunhofer ISI policy brief concludes that it should be a climate policy goal to further develop DACCS as an option to generate negative emissions, while bearing in mind the time needed for its development and deployment. A public debate on this still needs to be held. 

The Fraunhofer Institute for Systems and Innovation Research ISI analyzes the origins and impacts of innovations. We research the short- and long-term developments of innovation processes and the impacts of new technologies and services on society. On this basis, we are able to provide our clients from industry, politics and science with recommendations for action and perspectives for key decisions. Our expertise is founded on our scientific competence as well as an interdisciplinary and systemic research approach.