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In recent years, research on carbon dioxide removal (CDR) has significantly increased. Numerous studies have analyzed demonstration projects, outlined scenarios, modeled pathways, or focused on CDR's national or international governance. However, regional case studies investigating the dynamics that may facilitate or impede the broader adoption of CDR methods in spatially explicit settings are critically absent. Understanding implementation contexts on the ground is vital, and comparing them across different removal methods is essential for effectively scaling up CDR. This paper aims to address this research gap by comparatively examining the development of biomass-based CDR in three regions of Germany. Taking an exploratory approach, we conducted surveys in these regions to gain insight into stakeholder perceptions of the following six CDR methods: forest management, agriculture and soil carbon, long-lasting building materials, rewetting of peatlands and paludiculture, biochar, and bioenergy with carbon capture and storage. In this article, we present the results of the stakeholder survey, which offers multiple perspectives that can shape future studies of regional implementation and yield policy-relevant guidance. Although our research primarily focuses on the regional level in Germany, it sheds light on various conflicts, uncertainties, and potentials that are likely to be relevant for the rollout of CDR in other countries. By examining these aspects, we contribute to the broader discourse on CDR and its potential implementation. [ABSTRACT FROM AUTHOR]

Germany 2050: For the first time Germany reached a balance between its sources of anthropogenic CO2 to the atmosphere and newly created anthropogenic sinks. This backcasting study presents a fictional future in which this goal was achieved by avoiding (∼645 Mt CO2), reducing (∼50 Mt CO2) and removing (∼60 Mt CO2) carbon emissions. This meant substantial transformation of the energy system, increasing energy efficiency, sector coupling, and electrification, energy storage solutions including synthetic energy carriers, sector‐specific solutions for industry, transport, and agriculture, as well as natural‐sink enhancement and technological carbon dioxide options. All of the above was necessary to achieve a net‐zero CO2 system for Germany by 2050. Plain Language Summary: Here a net‐zero‐2050 Germany is envisioned by combining analysis from an energy‐system model with insights into approaches that allow for a higher carbon circularity in the German system, and first results from assessments of national carbon dioxide removal potentials. A back‐casting perspective is applied on how net‐zero Germany could look like in 2050. We are looking back from 2050, and analyzing how Germany for the first time reached a balance between its sources of CO2 to the atmosphere and the anthropogenic sinks created. This would consider full decarbonization in the entire energy sector and being entirely emission‐free by 2050 within three priorities identified as being the most useful strategies for achieving net‐zero: (a) Avoiding‐ (b) Reducing‐ (c) Removing emissions. This work is a collaboration of interdisciplinary scientists with the Net‐Zero‐2050 cluster of the Helmholtz Climate Initiative HI‐CAM. Key Points: The net‐zero system shows that for countries like Germany, avoiding CO2 emissions was the largest contribution to achieve net‐zero CO2With the three strategies of emissions avoidance, reduction, and removal, Germany has achieved its net‐zero CO2 goal for the first timeIn addition, to natural sink enhancement carbon dioxide removal (CDR) options, technological CDR measures combined with geological CO2 storage were necessary to reach net‐zero CO2 [ABSTRACT FROM AUTHOR]

Carbon capture and storage can both reduce greenhouse gas emissions and provide negative emissions to contribute to the transition to a net-zero society. The contribution of carbon capture and storage has been investigated within cross-sectorial energy system models. However, such models commonly focus on cost and greenhouse gas emissions, while broader environmental impacts are investigated for individual technologies only. Here, we analyze economic and environmental impacts of the transition to net-zero emissions by combining energy system modeling with life-cycle assessment. We focus on the system-wide implications of carbon dioxide storage on economic or environmental impacts. In our investigation of the transition of the German energy system until 2045, net-zero emissions require a minimal amount of carbon capture and storage. However, increasing carbon dioxide storage beyond the minimum amount significantly lowers cost and environmental impacts in up to 13 out of 16 impact categories by avoiding investments into material-intensive technologies, such as power-to-methane or renewable power plants in areas with low generation potential. In scenarios without electricity imports, carbon dioxide storage ranges between 118 Mt to 379 Mt in 2045 with cost increasing by 105 % when carbon dioxide storage is minimized. 84 % of the cost increase is incurred for eliminating the final 23 Mt of carbon dioxide stored. The benefits of applying carbon capture and storage are robust to variations in the amount of renewable electricity imports and residual emissions that require compensation. Hence, the results suggest that carbon capture and storage can offer economic and environmental benefits in the transition to net-zero energy systems beyond greenhouse gas emission mitigation. • Life-cycle assessment of transition to net-zero energy system for Germany. • Analysis of system effects of integrating carbon capture and storage in energy system. • Carbon capture and storage reduces cost and many environmental impact categories. • Impact reductions persist when varying electricity imports and residual emissions. [ABSTRACT FROM AUTHOR]

Background: To evaluate the economic implications of the pre-emptive use of extracorporeal carbon dioxide removal (ECCO2R) to avoid invasive mechanical ventilation (IMV) in patients with hypercapnic ventilatory insufficiency failing non-invasive ventilation (NIV). Methods: Retrospective ancillary cost analysis of data extracted from a recently published multicentre case–control-study (n = 42) on the use of arterio-venous ECCO2R to avoid IMV in patients with acute on chronic ventilatory failure. Cost calculations were based on average daily treatment costs for intensive care unit (ICU) and normal medical wards as well as on the specific costs of the ECCO2R system. Results: In the group treated with ECCO2R IMV was avoided in 90 % of cases and mean hospital length of stay (LOS) was shorter than in the matched control group treated with IMV (23.0 vs. 42.0 days). The overall average hospital treatment costs did not differ between the two groups (41.134 vs. 39.366 €, p = 0.8). A subgroup analysis of patients with chronic obstructive pulmonary disease (COPD) revealed significantly lower median ICU length of stay (11.0 vs. 35.0 days), hospital length of stay (17.5 vs. 51.5 days) and treatment costs for the ECCO2R group (19.610 vs. 46.552 €, p =0.01). Conclusions: Additional costs for the use of arterio-venous ECCO2R to avoid IMV in patients with acute-on-chronic ventilatory insufficiency failing NIV may be offset by a cost reducing effect of a shorter length of ICU and hospital stay. [ABSTRACT FROM AUTHOR]

Background: The combination of high-frequency oscillatory ventilation (HFOV) and extracorporeal carbon dioxide removal with the interventional lung assist (iLA) in severe acute respiratory distress syndrome (ARDS) represents a novel treatment option. Methods: The study used a retrospective single-center analysis of 21 consecutive adult patients with severe ARDS, ventilated with HFOV/iLA. Efficiency, side effects, and outcome of combined treatment are presented as median (interquartile range). Measurements and Main Results: The following were used to determine patient characteristics: sequential organ failure assessment score, 14; simplified acute physiology score II, 41; and Murray score, 4. The duration of combined treatment was 6 days. The blood flow through the iLA was 1.9 L/min. The Pao 2/inspired fraction of oxygen ratio increased from 61 (47-86) to 98 (67-116) within 2 hours and to 106 (70-135) mm Hg at 24 hours. Paco 2 decreased from 58 (50-76) to 37 (29-47) mm Hg at 2 hours with normalization of pH 7.28 (7.16-7.36) to 7.43 (7.33-7.49) after 2 hours associated with hemodynamic stabilization. In 6 patients, complications due to iLA treatment were observed, and in 3 patients, complications associated with HFOV were seen. Weaning from HFOV/iLA was successful in 10 patients. The 30-day mortality rate was 43%, and hospital mortality rate was 57%. Conclusion: The combination of HFOV/iLA is an option in severe pulmonary failure if conventional ventilation fails and pumpdriven extracorporeal membrane oxygenation therapy is not available. [Copyright &y& Elsevier]

A significant reduction in greenhouse gas emissions will be necessary in the coming decades to enable the global community to avoid the most dangerous consequences of man-made global warming. This fact is reflected in Germany's 7th Federal Energy Research Program (EFP), which was adopted in 2018. Direct Air Capture (DAC) technologies used to absorb carbon dioxide (CO2) from the atmosphere comprise one way to achieve these reductions in greenhouse gases. DAC has been identified as a technology (group) for which there are still major technology gaps. The intention of this article is to explore the potential role of DAC for the EFP by using a multi-dimensional analysis showing the technology's possible contributions to the German government's energy and climate policy goals and to German industry's global reputation in the field of modern energy technologies, as well as the possibilities of integrating DAC into the existing energy system. The results show that the future role of DAC is affected by a variety of uncertainty factors. The technology is still in an early stage of development and has yet to prove its large-scale technical feasibility, as well as its economic viability. The results of the multi-dimensional evaluation, as well as the need for further technological development, integrated assessment, and systems-level analyses, justify the inclusion of DAC technology in national energy research programs like the EFP. [ABSTRACT FROM AUTHOR]