OpenAIRE
Refine
Has Fulltext
- yes (359)
Year of Publication
Document Type
- Peer-Reviewed Article (347)
- Conference Object (12)
Direct air capture (DAC) combined with subsequent storage (DACCS) is discussed as one promising carbon dioxide removal option. The aim of this paper is to analyse and comparatively classify the resource consumption (land use, renewable energy and water) and costs of possible DAC implementation pathways for Germany. The paths are based on a selected, existing climate neutrality scenario that requires the removal of 20 Mt of carbon dioxide (CO2) per year by DACCS from 2045. The analysis focuses on the so-called "low-temperature" DAC process, which might be more advantageous for Germany than the "high-temperature" one. In four case studies, we examine potential sites in northern, central and southern Germany, thereby using the most suitable renewable energies for electricity and heat generation. We show that the deployment of DAC results in large-scale land use and high energy needs. The land use in the range of 167-353 km2 results mainly from the area required for renewable energy generation. The total electrical energy demand of 14.4 TWh per year, of which 46% is needed to operate heat pumps to supply the heat demand of the DAC process, corresponds to around 1.4% of Germany's envisaged electricity demand in 2045. 20 Mt of water are provided yearly, corresponding to 40% of the city of Cologne's water demand (1.1 million inhabitants). The capture of CO2 (DAC) incurs levelised costs of 125-138 EUR per tonne of CO2, whereby the provision of the required energy via photovoltaics in southern Germany represents the lowest value of the four case studies. This does not include the costs associated with balancing its volatility. Taking into account transporting the CO2 via pipeline to the port of Wilhelmshaven, followed by transporting and sequestering the CO2 in geological storage sites in the Norwegian North Sea (DACCS), the levelised costs increase to 161-176 EUR/tCO2. Due to the longer transport distances from southern and central Germany, a northern German site using wind turbines would be the most favourable.
This paper examines the current and prospective greenhouse gas (GHG) emissions of e-fuels produced via electrolysis and Fischer-Tropsch synthesis (FTS) for the years 2021, 2030, and 2050 for use in Germany. The GHG emissions are determined by a scenario approach as a combination of a literature-based top-down and bottom-up approach. Considered process steps are the provision of feedstocks, electrolysis (via solid oxide co-electrolysis; SOEC), synthesis (via Fischer-Tropsch synthesis; FTS), e-crude refining, eventual transport to, and use in Germany. The results indicate that the current GHG emissions for e-fuel production in the exemplary export countries Saudi Arabia and Chile are above those of conventional fuels. Scenarios for the production in Germany lead to current GHG emissions of 2.78-3.47 kgCO2-eq/L e-fuel in 2021 as the reference year and 0.064-0.082 kgCO2-eq/L e-fuel in 2050. With a share of 58-96%, according to the respective scenario, the electrolysis is the main determinant of the GHG emissions in the production process. The use of additional renewable energy during the production process in combination with direct air capture (DAC) are the main leverages to reduce GHG emissions.
Demand-side mitigation strategies have been gaining momentum in climate change mitigation research. Still, the impact of different approaches in passenger transport, one of the largest energy demand sectors, remains unclear. We couple a transport simulation model to an energy system optimisation model, both highly disintegrated in order to compare those impacts. Our scenarios are created for the case of Germany in an interdisciplinary, qualitative-quantitative research design, going beyond techno-economic assumptions, and cover Avoid, Shift, and Improve strategies, as well as their combination. The results show that sufficiency - Avoid and Shift strategies - have the same impact as the improvement of propulsion technologies (i.e. efficiency), which is reduction of generation capacities by one quarter. This lowers energy system transformation cost accordingly, but requires different kinds of investments: Sufficiency measures require public investment for high-quality public services, while efficiency measures require individuals to purchase more expensive vehicles at their own cost. These results raise socio-political questions of system design and well-being. However, all strategies are required to unleash the full potential of climate change mitigation.
Reaching net-zero in the chemical industry : a study of roadmaps for industrial decarbonisation
(2024)
Striving to mitigate climate change, the European Union has adopted net-zero greenhouse gas emissions as a target for 2050. In this paper, European chemical industry roadmaps from the past six years are assessed and compared to uncover how the industry envisions its role in the transition to net-zero emissions. The roadmaps are assessed in terms of ambition level, technology and feedstock strategies, investment needs and costs, agency and dependency on other actors, as well as timeline and concretion. Although net-zero pathways are often drawn out in the roadmaps, some also choose to emphasize and argue for less ambitious pathways with emission reductions of only 40-60 %. The roadmaps vary widely in terms of the importance they assign to mechanical and chemical recycling, switching to biogenic carbon and carbon dioxide as feedstock, electrification and hydrogen, and carbon capture and storage. A commonality though, is that low-tech or near-term mitigation pathways such as demand reduction, reuse or material efficiency are seldom included. High investment needs are generally highlighted, as well as the need for policy to create enabling conditions, whereas the agency and responsibility of the chemical industry itself is downplayed. Our analysis highlights that the chemical industry does not yet have a strong and shared vision for pathways to net-zero emissions. We conclude that such a future vision would benefit from taking a whole value chain approach including demand-side options and consideration of scope 3 emissions.
Biodiversity is under threat all over the planet. Implementing sustainable out-of-home catering (OHC) is a key way to reduce the environmental impact of the agri-food sector. Thus far, there have been no studies that show the impact of food on biodiversity at the menu level in Germany. This means that neither commercial kitchens nor their patrons can record the biodiversity impact of the menus or dishes served there. This article describes the development of an assessment framework and some initial findings. The framework was developed on the basis of a systematic literature review and expert interviews. Taking this as a starting point, an indicator-based approach was developed with a focus on land use. The approach was then validated by assessing recipes used at OHC facilities. The results show that using the BiTe Biodiversity Index (BBI) that was developed, it is possible to assess the biodiversity impacts of meals and optimize them at the level of the dish. The article outlines the possible areas for improvement. Overall, it is clear that this approach can already be used in the OHC context today.
The international architecture competition Solar Decathlon Europe was held in Wuppertal in 2022 and focused on sustainable building and living in the city. The student teams participating in the competition developed buildings that would enable climate-friendly living and be tailored to the "Mirke" district in Wuppertal and the individual needs of the residents in this neighborhood. Not only the neighborhood was the focus of the competition, but also the residents of the Mirke district were involved in the project through a neighborhood panel. As part of the Mirke neighborhood panel, three survey waves were conducted between May 2021 and August 2022. The results and insights gained from the neighborhood panel were incorporated into the project and shared with the architectural teams participating in the competition. In addition, the results were shared and discussed with the urban development department of the city of Wuppertal, local initiatives, and other partners in the neighborhood.
Strengthening global climate governance and international cooperation for energy‐efficient buildings
(2023)
Buildings constitute one of the main GHG emitting sectors, and energy efficiency is a key lever to reduce emissions in the sector. Global climate policy has so far mostly focused on economy-wide emissions. However, emission reduction actions are ultimately sectoral, and opportunities and barriers to achieving emission reductions vary strongly among sectors. This article therefore seeks to analyse to what extent more targeted global governance may help to leverage mitigation enablers and overcome barriers to energy efficiency in buildings. To this end, the article first synthesises existing literature on mitigation enablers and barriers as well as existing literature on how global governance may help address these barriers ("governance potential"). On this basis, the article analyses to what extent this governance potential has already been activated by existing activities of international institutions. Finally, the article discusses how identified governance gaps could be closed. The analysis finds that despite the local characteristics of the sector, global governance has a number of levers at its disposal that could be used to promote emission reductions via energy efficiency. In practice, however, lacking attention to energy efficiency in buildings at national level is mirrored at the international level. Recently, though, a number of coalitions demanding stronger action have emerged. Such frontrunners could work through like-minded coalitions and at the same time try to improve conditions for cooperation in the climate regime and other existing institutions.
As investors and financial intermediaries, private banks are increasingly confronted with climate change concerns. But to what extent do banks identify as the changemakers driving climate alignment forward? To advance this question, this paper analyzes the South African banking sector with a specific focus on Standard Bank and Nedbank as exemplary case studies. Relying on the concept of "climate mainstreaming", we critically assess the banks' annual reports and compare their self-portrayal with publicly available sources on the bank's business practices, chiefly provided by non-governmental organizations and media. We find that Nedbank pushes a holistic narrative of climate change as an inevitable business opportunity. Standard Bank, in turn, relies on a "narrative of balance" between climate change and other profit-oriented investments to safeguard its stakes in the fossil industry. In so doing, this paper sheds light on greenwashing practices within disclosure specifically and the lack of binding corporate regulation more generally.
There is a growing body of scientific evidence supporting sufficiency as an inevitable strategy for mitigating climate change. Despite this, sufficiency plays a minor role in existing climate and energy policies. Following previous work on the National Energy and Climate Plans of EU countries, we conduct a similar content analysis of the recommendations made by citizen assemblies on climate change mitigation in ten European countries and the EU, and compare the results of these studies. Citizen assemblies are representative mini-publics and enjoy a high level of legitimacy.
We identify a total of 860 mitigation policy recommendations in the citizen assemblies' documents, of which 332 (39 %) include sufficiency. Most of the sufficiency policies relate to the mobility sector, the least relate to the buildings sector. Regulatory instruments are the most often proposed means for achieving sufficiency, followed by fiscal and economic instruments. The average approval rate of sufficiency policies is high (93 %), with the highest rates for regulatory policies.
Compared to National Energy and Climate Plans, the citizen assembly recommendations include a significantly higher share of sufficiency policies (factor three to six) with a stronger focus on regulatory policies. Consequently, the recommendations can be interpreted as a call for a sufficiency turn and a regulatory turn in climate mitigation politics. These results suggest that the observed lack of sufficiency in climate policy making is not due to a lack of legitimacy, but rather reflects a reluctance to implement sufficiency policies, the constitution of the policy making process and competing interests.
The rise of pedal-assisted bicycles (e-bikes) has the potential to contribute to reducing ubiquitous automobility and its negative externalities on the global climate, mobility justice and the quality of urban life. But what makes this new practice so successful in recruiting new practitioners? What policies can ensure that e-bikes are used in a wide range of situations, thus substituting as much car driving as possible - or even reducing the number of cars? The study focuses on commuting as this use case frequently entails the main obstacles to e-biking in daily routines (e.g., sweat, weather, transporting children or goods). The analysis is primarily based on interviews with practitioners and initially provides a thorough depiction of the practice elements (meanings, materials and competences) involved in e-bike commuting. It furthermore elicits key drivers of and barriers to daily e-bike commuting, points to a number of elements that are important to overcome these barriers and develops two tangible policy approaches to foster the substitution of e-biking for car driving.