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Drained peatland currently contributes 7.5% of Germany's total national greenhouse gas emissions. The National Peatland Protection Strategy adopted by the German government in 2022 recognizes that these emissions need to be reduced significantly to meet the country's climate change mitigation commitments. The present study employs a global dynamic computable general equilibrium model to assess the economic and greenhouse gas emission impacts of alternative agriculture-focused peatland rewetting scenarios for Germany up to 2030. In contrast to partial-analytic approaches, the global general equilibrium approach allows to take consistent account of economic ripple-on effects and carbon leakage effects triggered by peatland rewetting. The results suggest that in the medium term towards 2030 a reduction in annual emissions from agricultural peatland use by up to 45% are attainable at marginal private abatement costs between 27 and 61 Euro/tCO 2 e. Carbon leakage effects due to induced indirect land use change in Germany and the rest of the European Union reduce the global net emission reduction impact by 0.7 to 1.0% of the direct emission reduction. The effects on food prices remain small in all scenarios. In conclusion, a sizable reduction of Germany's land-use-related emissions is achievable at a low macroeconomic cost by moving beyond the moderate ambitions of the National Peatland Restoration Strategy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hedgerows and adjacent croplands at 23 sites across Germany were sampled. • Under hedgerows, 36 ± 49 % more soil organic carbon (SOC) was stored compared to cropland. • 41 % of absolute SOC stock increase was found in subsoil below 30 cm soil depth. • SOC stocks were also increased along the transect from the hedgerow to the cropland. • Planting hedgerows on 3 % of German cropland could increase SOC stocks by 13 Tg C. Carbon dioxide removal strategies are becoming increasingly important as a fundamental component of comprehensive climate policies. One strategy to increase carbon (C) sinks is the integration of hedgerows into agricultural landscapes. Besides additional C storage in above-ground and below-ground hedgerow biomass, the establishment of hedgerows has the potential to increase soil organic carbon (SOC) stocks. However, empirical data regarding the magnitude of SOC accrual with hedgerow establishment are still limited. We sampled 23 sites across Germany in a paired-plot approach with the aim of estimating SOC stock change with hedgerow establishment on cropland. At 21 sites, SOC stocks were higher beneath hedgerows than in the reference cropland. On average, SOC stock accrual was 29 ± 22 Mg ha−1 (36 ± 49 %) in 0–100 cm soil depth. SOC stocks were significantly different in both topsoil and subsoil. Subsoils below 30 cm depth contributed 41 % (12 ± 17 Mg C ha−1) of the total SOC stock change, stressing the importance of subsoil SOC for the total SOC stocks of hedgerow systems. The positive effect of hedgerows on SOC stocks extended laterally beyond the hedgerow area itself. SOC stock in the grassy hedgerow edge also increased significantly by 22 ± 22 Mg C ha−1 (28 ± 30 %) and SOC stock in the cropland directly adjacent to the hedgerow were 9 ± 19 Mg C ha−1 (12 ± 25 %) higher than in the reference cropland. Particularly high C stock differences between hedgerows and reference cropland soils were found in old hedgerows (>200 years) planted on hedgebanks, which are typically found in northern Germany. Our study confirmed that SOC stocks increase with hedgerow establishment on cropland throughout the whole soil profile. If hedgerows were to be established on 3 % of Germany's cropland area, SOC stocks would increase by 13 Tg C equivalent 48 Mio. t CO 2 , highlighting that hedgerows are a promising and multi-functional climate change mitigation option. [ABSTRACT FROM AUTHOR]

Identifying transmission sectors that may not be revealed by existing indicators, such as production-based emission (PBE) and consumption-based emission (CBE) accounting, is significant in emission reduction policies and provides insights into novel opportunities for companies and industries to reduce emissions. This study proposed an intermediate-based emission (IBE) accounting approach that considers indirect emissions from intermediate goods production and a case study was conducted using Exiobase 3.8. The highest IBE sector was 'basic iron' (1131 Mt-CO 2), and the sector's IBE was higher than its PBE (1052 Mt-CO 2). Additionally, the material sector, such as aluminum products (326 Mt-CO 2), was identified as a key transmission sector, although PBE (21 Mt-CO 2) and CBE (3 Mt-CO 2) of the sector is very low. In addition, IBEs were observed to be closely related to overall supply chain emissions in Germany, Japan, and Asia, and cooperation is required to reduce the emissions. The method enables approaching supply chains with large emissions from three perspectives (production-, consumption-, and intermediate-based accounting) and exploration of the emission reduction responsibilities of the three key sectors. The utility and discussion of the approach are consistent with Scope 3 emissions and facilitate fair allocation of emission reduction responsibilities to a larger number of countries and industries. • This study suggested intermediate-based emission (IBE) accounting. • Industries such as basic iron have high production–based emissions but higher IBE. • Intermediate industries not focused on by existing emission accounting identified. • Existing betweenness-based emission accounting much higher than actual emissions. • Germany, Japan, and Asian HEMs have strong correlation with IBE. [ABSTRACT FROM AUTHOR]

Agricultural management can influence soil organic carbon (SOC) stocks and thus may contribute to carbon sequestration and climate change mitigation. The soil depth to which agricultural management practices affect SOC is uncertain. Soil depth may have an important bearing on soil carbon dynamics, so it is important to consider depth effects to capture fully changes in SOC stocks. This applies in particular to the evaluation of carbon farming measures, which are becoming increasingly important due to climate change. We sampled and analysed the upper metre of mineral cropland soils from ten long-term experiments (LTEs) in Germany to quantify depth-specific effects on SOC stocks of common agricultural management practices: mineral nitrogen (N) fertilisation, a combination of N, phosphorus (P) and potassium (K) fertilisation, irrigation, a crop rotation with preceding crops (pre-crops), straw incorporation, application of farmyard manure (FYM), liming, and reduced tillage. In addition, the effects of soil compaction on SOC stocks were examined as a negative side effect of agricultural management. Results showed that 19 ± 3 % of total management effects on SOC stocks were found in the upper subsoil (30–50 cm) and 3 ± 4 % in the lower subsoil (50–100 cm), including all agricultural management practices with significant topsoil SOC effects, while 79 ± 7 % of management effects were in the topsoil (0–30 cm). Nitrogen and NPK fertilisation were the treatments that had the greatest effect on subsoil organic carbon (OC) stocks, followed by irrigation, FYM application and straw incorporation. Sampling down to a depth of 50 cm resulted in significantly higher SOC effects than when considering topsoil only. A crop rotation with pre-crops, liming, reduced tillage and soil compaction did not significantly affect SOC stocks at any depth increment. Since approximately 20 % of the impact of agricultural management on SOC stocks occurs in the subsoil, we recommend soil monitoring programs and carbon farming schemes extend their standard soil sampling down to 50 cm depth to capture fully agricultural management effects on SOC. • Ten 32- to 112-year-old long-term experiments were sampled down to 100 cm depth. • Sampling only topsoil ignores 20 % of agricultural management effects on SOC stocks. • Mineral fertilisation had the greatest effect on subsoil organic carbon stocks. • None of the agricultural measures had significant effects deeper than 50 cm. • Standard soil sampling should therefore be extended to 50 cm depth. [ABSTRACT FROM AUTHOR]

[Display omitted] • First-time framing of renewable energy priority zones. • Definition of optimal combinations of advanced meteorological-technical criteria. • Application of wavelet analysis and coherence in a multi-criteria site assessment. • Wind energy priority zones found in 2–12% of Germany based on restriction scenario. • Solar energy priority zones found in 5–22% of Germany based on restriction scenario. The intensification of climate change impacts requires a fast and efficient transition of energy systems and deployment of renewable energies worldwide. An adequate site assessment strategy forms the basis for expanding installed capacities and energy yield. This study applies a set of meaningful criteria to determine site suitability for Germany's onshore wind and utility-scale solar photovoltaics facilities. An aggregated priority index involving meteorological-technical, economic, and environmental criteria is developed and used in a new concept for identifying renewable energy priority zones, where installations of wind and solar energy facilities should be prioritized. As a novelty, this resource-centered approach does not only analyze the mean energy potential as a meteorological criterion but also accounts for other characteristics such as variability, complementarity, and predictability. The results indicate that reducing legal restrictions substantially facilitates wind and solar energy capacity expansion in prioritized zones. With weak restrictions, up to 22% and 12% of Germany represent priority zones for an efficient and sustainable use of solar and wind energy. However, due to the intermittent nature of wind and solar resources, mismatches between generation potential and electricity demand would persist even with substantial capacity expansion. Future energy systems must advance the expansion of renewable energy capacities just as the flexibilization of demand or an increase of storage capacities to guarantee future energy security and mitigate climate change. The newly developed renewable energy priority zones are a starting point and can be transferred to other study areas by specifically adapting criteria and their weighting. [ABSTRACT FROM AUTHOR]

• Arable measures bear high potential to affect topsoil SOC stocks. • Mineral and organic fertilization, straw incorporation caused major SOC gain. • Liming and reduced tillage had little or even negative effects on SOC storage. • Sandy soils exhibited the largest relative response to management options. • Up to 10‰ SOC accrual per year were reached by combination of measures. Crop production often leads to soil organic carbon (SOC) losses. However, under good management practice it is possible to maintain and even re-accumulate SOC. We evaluated how different cropland management techniques affected SOC stocks in the topsoil (0–30 cm depth) of 10 long-term experiments (LTE) in Germany. We found that SOC stocks were particularly enhanced by mineral fertilization and organic amendments like straw incorporation and to a smaller degree by irrigation, but only slightly affected by the choice of preceding crops. In agreement with global meta -analyses, liming and reduced tillage had little or even negative effects on SOC storage, but effects also depended on fertilization. Management effects on SOC stocks were dependent on soil texture: sandy soils showed the lowest SOC stocks of 20.9 ± 2.3 (standard error of the mean) Mg ha−1, but exhibited the largest relative response to different management options. Annual changes in SOC stocks ranged from −3.0 ‰ with no mineral N fertilization, to + 6.1 ‰ with farmyard manure application, using the mineral-fertilized and limed treatment as reference. Even higher rates of up to + 10.6 ‰ yr−1 were reached with the combination of irrigation and straw incorporation. Note that the contribution of organic amendments to SOC accrual and thus to climate change mitigation must be adjusted for reduction in SOC at sites from which straw was removed. Overall, the potential of agricultural management to influence and enhance SOC stocks is significant. This potential is controlled by soil type and land-use duration, is largest for sandy soils with overall lowest SOC stocks, and is characterized by antagonistic and synergistic effects of different management practices. [ABSTRACT FROM AUTHOR]

• A south-north-gradient of the yield can be identified in most years. • More than half of roof-top PV systems operate worse than expectable. • At least 5 years of data must be available for a quality statement of PV systems. • There is no correlation of yield and capacity of roof-top PV systems. The photovoltaic (PV) sector is a central pillar for the global energy transition process which aims to reach the climate change mitigation goals. Roof-mounted systems in particular can make a significant contribution to greenhouse gas-free energy generation. By the end of 2018, more than 1.5 million rooftop systems have been installed in Germany. The yield data measured by monitoring systems and provided by web-based online systems from 2012 to 2018, as well as the configuration information of 23,944 PV systems, are evaluated in this publication. Long-term indicators are derived from the spatial and temporal distribution of the yield data. The yield analysis shows a typical south-north gradient in Germany. 2018 was the year with the highest yield, 2013 the year with the lowest. The annual specific yield varies between 816 kWh/kW p in 2017 at the Baltic Sea and 1049 kWh/kW p in 2018 in Bavaria. If analysis of data evaluation is narrowed to one to two years, a deviation of five percent and more from the long-term yield can be observed. In order to obtain detailed information on the quality of PV systems, at least five years of data are required. The yield data evaluation can be used by PV system operators and owners to identify an undersupply of their PV system and to initiate countermeasures. [ABSTRACT FROM AUTHOR]

Germany remains the only large country in the world without a general speed limit on highways. One of the main arguments for this policy is that lower speeds represent a travel time cost that is not outweighed by benefits, such as a reduction in greenhouse gas emissions. As transport decision making in the European Union is based on cost-benefit analysis (CBA), this paper compares the value of travel time, fuel consumption, infrastructure, crashes, carbon dioxide (CO 2), and air pollution. Results suggests that, at the low end of the estimate, a 130 kph speed limit will generate welfare gains in the order of 950 million Euro per year. The 'no speed limit' policy consequently represents a subsidy forwarded to fast drivers. The paper also discusses the views of the public vis-à-vis automobile lobbies, and the relevance of Germany's climate change mitigation law, mandating that transport systems be decarbonized. The CBA suggests that a 130 kph speed limit is a policy field where environmental concerns, positive economic effects, and public opinion can be aligned. [ABSTRACT FROM AUTHOR]

[Display omitted] • Topsoil SOC stocks and soil structure recovered 26 years after topsoil removal. • Topsoil buried under the plough layer non-linearly lost 30–50% of SOC in 55 years. • Topsoil SOC recovery and stability of buried SOC was dependent on N fertilisation. Erosion of fertile topsoil means severe land degradation and yield loss. Here, we show that reformation of the fertile topsoil and crop yield increase is possible by good agricultural management within a few decades. Evidence relies on a unique long-term field experiment in NE Germany, where in 1964 the sandy soil (Luvisol) had been excavated to 52 cm and refilled with subsoil material of 52 cm thickness. Undisturbed trials served as controls, these were all combined with either no fertilisation, mineral fertilisation or a combined mineral and organic fertilisation. It took only 26 years until new topsoil had been formed. Its soil organic carbon (SOC) and total N stocks and the aggregate size distributions equalled that of the other treatments; SOC sequestration corresponded to 28 Mg SOC ha−1. The former topsoil buried below the plough layer lost 30–50 percent of its SOC during 5 decades in a non-linear manner. We conclude that our current agricultural tools can restore degraded arable land rather fast and contribute to climate change mitigation through a significant SOC sequestration as well. [ABSTRACT FROM AUTHOR]

Climate models project higher temperatures and a substantial net water deficit during the summer months over Germany until the end of the 21st century. The agricultural sector is particularly vulnerable to changing weather and climate conditions. In this study, we examine the role of irrigation for potato yields as a climate change adaptation measure in Northeast Lower Saxony (Germany). The region represents the largest irrigated area in Germany and is one of the main growing areas of potatoes. We develop a statistical multivariate regression model to investigate whether regional climate and irrigation data at the monthly and county level are suitable to describe potato yield variability from 1978 to 2018. Irrigation is estimated based on the climatic water balance and crop water demand. These estimates are calibrated against irrigation data from local agencies to account for realistic monthly water withdrawals. We analyze future yield changes based on climate model projections for the 21st century and different irrigation scenarios. We find that the potato yield will decrease significantly by 18% on average until 2050 with climate projection uncertainty of ±6.4% under the high emission scenario RCP 8.5 and without irrigation. Irrigation at current levels could compensate for about 54% of these yield losses. Doubling the amount of irrigation minimizes yield losses by as much as 80%. Under the low (middle) emission scenario RCP 2.6 (RCP 4.5), potato yield are projected to decrease moderately by 4.5% ± 3.4% (5.4% ± 2.8%) with irrigation at current levels. We show that the yield losses mainly originate from higher temperatures during the summer. Our analysis indicates that the capacity of irrigation to minimize yield losses is limited. Strengthening climate change mitigation efforts may be more effective in preventing yield losses. However, the effect of elevated CO 2 might buffer the high yield losses, especially in RCP 8.5. The studies supports farmers and decision makers in assessing future risks in potato yields. It can guide policymakers in allocating economic resources to cope with climate change. [Display omitted] • Potato yields in Germany will decrease sharply under climate change for RCP8.5. • Irrigation at current levels mitigates about half of the yield losses. • Irrigation potential is limited because it can not buffer high temperatures. • Climate change mitigation and other adaption actions need to complement irrigation. • The effect of elevated CO2 might buffer high yield losses, especially in RCP8.5. [ABSTRACT FROM AUTHOR]

Will climate change be mitigated automatically by ongoing processes of urbanization as proposed by the “dense cities” hypothesis? Our answer is based on the German official income and expenditure survey (EVS) of 2013, which allow us to disaggregate total household expenditures into 44 consumer good categories (COICOP) and their respective GHG intensities. Results show that the density effect of cities saves some greenhouse gas (GHG) emissions in Germany, but singularisation of households, higher incomes and greater consumption opportunities in cities work in the opposite direction. Thus, smaller and larger municipalities are more or less on par with each other in terms of per capita emissions. Rural households are found to be more affected by environmental taxes which are imposed on direct rather than on indirect energy use in the course of German “Energiewende” policy reform. This is discussed in the article as a rural-urban social equity problem. [ABSTRACT FROM AUTHOR]

In the context of climate change mitigation and sustainable energy infrastructure development, this paper focuses on the successful implementation of microgrids supplied by renewable energies in very diverse environments. Taking into account the challenges of reaching economies of scale, this paper is targeted at identifying success factors for microgrid implementation. The success factors are derived from case study analyses of microgrids implemented in the Global South and in communities of Germany. The goal of the research is to develop a mutual understanding of common values and so support future developments. The analysis covers the categories of ownership and participation; technology and system design; and policy and financing. The results show that microgrids in the Global South and renewable-energy-based communities in Germany share a number of success factors. The results demonstrate that a high share of ownership by users and the flexibility to expand the microgrid with user needs are particularly promising features. To verify the application of the identified success factors, the latter are applied to analyze the microgrid concept of “swarm electrification”. The analysis concludes that the concept of swarm electrification is consistent with the success factors, making it a high-potential approach for renewable-energy-based electrification. [ABSTRACT FROM AUTHOR]

The determination of the total carbon storage of peatlands is of high relevance in the context of climate-change mitigation efforts. This determination relies on data about stratigraphy and peat properties, which are conventionally collected by coring. Ground-penetrating radar (GPR) and electrical resistivity imaging (ERI) can support these point data by providing subsoil information in two-dimensional cross-sections. In this study, GPR and ERI were conducted at two groundwater-fed fen sites located in the temperate zone in north-east Germany. The fens of this region are embedded in low conductive glacial sand and are characterised by thick layers of gyttja, which can be either mineral or organic. The two study sites are representative of this region with respect to stratigraphy (total thickness, peat and gyttja types) and ecological conditions (pH-value, trophic condition). The aim of this study is to assess the suitability of GPR and ERI to detect stratigraphy and peat properties under these characteristic site conditions. Results show that GPR clearly detects the interfaces between (i) Carex and brown-moss peat, (ii) brown-moss peat and organic gyttja, (iii) organic- and mineral gyttja, and (iv) mineral gyttja and the parent material (glacial sand). These layers differ in bulk density and the related organic matter content. ERI, however, does not delineate these layers; rather it delineates regions of varying properties. At our base-rich site, pore fluid conductivity and cation exchange capacity are the main factors that determine peat electrical conductivity (reverse of resistivity), whereas organic matter and water content are most influential at the more acidic site. Thus the correlation between peat properties and electrical conductivity are driven by site-specific conditions, which are mainly determined by the solute load in the groundwater at fens. When the total organic deposits exceed a thickness of 5 m, the depth of investigation by GPR is limited due to increasing attenuation. This is not a limiting factor for ERI, where the transition from organic deposits to glacial sand is visible at both sites. Due to these specific sensitivities, a combined application of GPR and ERI meets the demand for up-to-date information on carbon storage of peatlands, which is, moreover, very site-specific because of the inherent variety of ecological conditions and stratigraphy between peatlands in general and between fens and bogs in particular. [ABSTRACT FROM AUTHOR]

CO 2 emissions from global steel production may jeopardize climate goals of 1.5 °C unless current steel production practices will be rapidly decarbonized. At present, primary iron and steel production is still heavily dependent on fossil fuels, primarily coke. This study aims to determine which decarbonization pathways can achieve the strongest emission reductions of the iron and steel industry in Germany by 2050. Moreover, we estimate whether the German iron and steel industry will be able to stay within its sectoral carbon budgets for a 1.5 °C or 1.75 °C target. We developed three decarbonization scenarios for German steel production: an electrification, coal-exit, and a carbon capture and storage (CCS) scenario. They describe a phase-out of coal-fired production plants and an introduction of electricity-based, low-carbon iron production technologies, i.e. hydrogen-based direct reduction and electrowinning of iron ore. The scenarios consider the age and lifetimes of existing coal-based furnaces, the maturity of emerging technologies, and increasing recycling shares. Based on specific energy requirements and reaction-related emissions per technology, we calculated future CO 2 emissions of future steel production in Germany. We found that under the decarbonization scenarios, annual CO 2 emissions decrease by up to 83% in 2050 relative to 2020. The reductions of cumulative emissions by 2050 range from 24% (360 Mt CO 2) under the electrification scenario up to the maximum of 46% (677 Mt CO 2) under the CCS scenario compared to a reference scenario. This clearly demonstrates that the technology pathway matters. Nevertheless, the German steel sector will exceed its sectoral CO 2 budget for a 1.5 °C warming scenario between 2023 and 2037. Thus, drastic measures are required very soon to sufficiently limit future CO 2 emissions from German steel production, such as, a rapid decarbonization of the electricity mix, the construction of a hydrogen and CCS infrastructure, or early shutdowns of current coal-based furnaces. [Display omitted] • Scenarios for iron and steel production in Germany until 2050 • Adopting new technologies: hydrogen-based direct reduction and electrowinning • Comparison of CO 2 emissions with sectoral carbon budgets for the steel industry • Carbon budget for climate goal of 1.5 °C likely to be exceeded between 2023 and 2037 • Carbon capture scenario achieves lowest CO 2 emissions but has higher energy demand [ABSTRACT FROM AUTHOR]

CO 2 emissions from global steel production may jeopardize climate goals of 1.5 °C unless current steel production practices will be rapidly decarbonized. At present, primary iron and steel production is still heavily dependent on fossil fuels, primarily coke. This study aims to determine which decarbonization pathways can achieve the strongest emission reductions of the iron and steel industry in Germany by 2050. Moreover, we estimate whether the German iron and steel industry will be able to stay within its sectoral carbon budgets for a 1.5 °C or 1.75 °C target. We developed three decarbonization scenarios for German steel production: an electrification, coal-exit, and a carbon capture and storage (CCS) scenario. They describe a phase-out of coal-fired production plants and an introduction of electricity-based, low-carbon iron production technologies, i.e. hydrogen-based direct reduction and electrowinning of iron ore. The scenarios consider the age and lifetimes of existing coal-based furnaces, the maturity of emerging technologies, and increasing recycling shares. Based on specific energy requirements and reaction-related emissions per technology, we calculated future CO 2 emissions of future steel production in Germany. We found that under the decarbonization scenarios, annual CO 2 emissions decrease by up to 83% in 2050 relative to 2020. The reductions of cumulative emissions by 2050 range from 24% (360 Mt CO 2) under the electrification scenario up to the maximum of 46% (677 Mt CO 2) under the CCS scenario compared to a reference scenario. This clearly demonstrates that the technology pathway matters. Nevertheless, the German steel sector will exceed its sectoral CO 2 budget for a 1.5 °C warming scenario between 2023 and 2037. Thus, drastic measures are required very soon to sufficiently limit future CO 2 emissions from German steel production, such as, a rapid decarbonization of the electricity mix, the construction of a hydrogen and CCS infrastructure, or early shutdowns of current coal-based furnaces. [Display omitted] • Scenarios for iron and steel production in Germany until 2050 • Adopting new technologies: hydrogen-based direct reduction and electrowinning • Comparison of CO 2 emissions with sectoral carbon budgets for the steel industry • Carbon budget for climate goal of 1.5 °C likely to be exceeded between 2023 and 2037 • Carbon capture scenario achieves lowest CO 2 emissions but has higher energy demand [ABSTRACT FROM AUTHOR]

Crop breeding has boosted global agricultural productivity over recent decades, but little is known about its contribution to climate change mitigation. Here we assess greenhouse gas emissions per unit land (GHGL) and greenhouse gas emissions per unit harvest product, i.e. carbon footprint (CFP) of winter wheat (Triticum aestivum) and winter rye (Secale cereale) from official German variety trials in the period 1983 to 2019. We assess the life cycle greenhouse gas (GHG) emissions and analyze the data using mixed effects models. We find that breeding progress led to slightly increased GHGL , amounting to ∼4–10%, but to strongly decreasing CFP, amounting to ∼13–23% in wheat and rye since 1983. With a ∼20% lower GHGL and ∼8% lower CFP in rye compared to wheat, the extension of rye production offers viable climate change mitigation potential. Finally, we find that lower CFP are associated with hybrid breeding, chemical plant protection and larger farms. We conclude that with increasing global food demand and limited cropland, breeding progress contributes considerably to climate change mitigation through reduced CFP. • First evidence on the contribution of breeding progress to climate change mitigation. • 27,652 and 10,523 Genotype x Environment x Management-combinations of wheat and rye. • Rye has lower greenhouse gas emissions (∼20%) and carbon footprint (∼8%) than wheat. • Crop breeding decreased carbon footprint in wheat and rye by ∼13–23% since 1983/1985. [ABSTRACT FROM AUTHOR]

Many studies have analysed the environmental impact of vegan, vegetarian, or reduced meat diets. To date, literature has not evaluated how diet shifts affect environmental impacts by utilising portfolios which reflect personal nutrition preferences. Further, changing diets could alter the available land for non-food uses. This paper defines novel diet portfolios to outline alternative diet transitions and choices within the population and finds their effect on greenhouse gas (GHG) emissions, primary energy use, and land use in Germany. The aim of this study is to capture how these diet shifts affect land availability and increase the options for land-based climate change mitigation strategies. To do so, a contextualisation is made to compare the use of freed-up land for afforestation or biomethane production (with and without carbon capture and storage). The investigated diet portfolios lead to a reduction of the investigated impacts (GHG emissions: 7–67%; energy use: 5–46%; land use: 6–64%). Additionally, afforestation of freed-up land from each diet portfolio leads to further emission removals of 4–37%. In comparison, using the land to produce energy crops for biomethane production could lead to 2–23% further CO2-eq emission reductions when replacing fossil methane. If biomethane production is paired with carbon capture and storage, emission abatement is increased to 3–34%. This research indicates various short-term pathways to reduce GHG emissions with portfolio diet shifts. Utilising freed-up land for climate change mitigation strategies could prove essential to meet climate targets, but trade-offs with, e.g. biodiversity and ecosystem services exist and should be considered. • Diet portfolios are used to represent realistic population diets. • Diet portfolios include a mixture of 12 different diets. • GHG emissions decrease by 67% if the population adopts a Vegan diet. • Afforestation removes almost double the emissions compared to biomethane. • BECCS has similar GHG abatement to afforestation. [ABSTRACT FROM AUTHOR]

Abstract: One of the cheapest ways to reduce CO2 emissions is thermal renovation of existing homes. Germany is a world leader in this project, with a strict building code, generous state subsidies, and an advanced renovation infrastructure. The effects of its policies are here explored in the light of progressive tightening of the building code, and the strict criteria for subsidies. Data on costs and outcomes of residential building renovations are presented from published reports on renovation projects, and cross-checked with projects investigated directly. Comparisons are made in terms of euros invested for every kilowatt hour of heating energy saved over the lifetime of the renovations, for standards ranging from 150kWh (the lowest standard) to 15kWh (the highest) of primary energy use per square metre of floor area per year. It is found that the lowest standard is an order of magnitude more cost-effective than the highest, in terms of both energy saved per euro invested, and return on investment over the lifetime of the renovations, regardless of fuel prices. It is argued that this throws into question Germany''s policy of progressively regulating for higher renovation standards, and offering subsidies only for projects that go beyond the minimum standard. [Copyright &y& Elsevier]

Climate change mitigation triggers both spatial and moral complexities, as demonstrated by the contentious issue of phasing out coal power. The success of the Paris Agreement depends on, among other things, the acceptability of climate policy measures and thus, from a moral perspective, on the ability to organize transition processes in ways that do not damage the livelihoods of workers, communities, and entire regions. Spatially, the unequal distributions of burdens and advantages of both climate change and respective mitigation measures provoke struggles over their legitimacy in contexts ranging from local to global. Phasing out coal mining and the respective power generation capacity thus triggers processes of structural transformation that cut across geographic scales, vertical levels of policy and politics, as well as sectoral boundaries. In light of the urgency of the climate crisis, countries such as Canada and Germany have established stakeholder-driven commissions to develop proposals for just transition pathways for phasing out coal production and consumption. We argue that these commissions are arenas in which spatial, moral, and sectoral (re-)negotiations materialize. Comparing the Canadian and German stakeholder commissions through expert interviews with their members, the article traces how governments use commissions to legitimize their transition policies. Expectations at different levels and from different actors in turn place commission members under pressure to justify their involvement and the outputs of the commissions. We find that the Canadian task force showed greater commitment to collecting and reflecting the needs of communities in its coal regions, and to communicating these to the federal government. In the German coal commission, legitimation strategies focused mainly on a broad representation of interests, and on government spending for affected regions, workers, and industries. In that case, a compromise was reached that satisfied most, but not all, of the diverse requirements. [ABSTRACT FROM AUTHOR]

Carbon neutral labeling of food products is a market-based approach to reduce carbon footprints in the agri-food sector. To better understand consumers' preferences and attitudes towards a carbon neutral label on globally traded agri-food products, the willingness to pay (WTP) of German consumers for a carbon neutral label on specialty coffee was examined. A discrete choice experiment was conducted in Germany, where coffee is often sold with multiple labels or claims, in order to examine the WTP for alternative combinations of a carbon neutral label with either a Fair Trade label or a claim of direct trade coffee sourcing. Choice data were analyzed using random parameter logit models which determined a positive WTP for the carbon neutral label. This estimate exceeds the corresponding marginal costs of certification and the marginal social cost of carbon, yet it is relatively lower than the estimated WTP for the Fair Trade label and the direct trade claim. A positive synergy effect on utility was also determined for the combination of a carbon neutral label and a direct trade claim. If no additional information was provided, consumers often perceived coffee as a "natural product" that does not generate any greenhouse gas emissions. Thus, awareness-building policies are needed to make carbon neutral labels an effective market-based tool to reduce greenhouse gas emissions in the agri-food sector. • German consumers are willing to pay for a carbon neutral label on specialty coffee. • The WTP for a carbon neutral label was lower than that for ethical trade claims. • We found a positive synergy between the carbon label and a direct trade claim. • Consumers have limited awareness of greenhouse gas emissions in coffee value chains. • Carbon neutral labeling needs to be leveraged with education campaigns to make it effective. [ABSTRACT FROM AUTHOR]

• Climate impact analysis of air transport from Germany. • Scenario dependent forecast of passenger flights from Germany. • Scenario dependent forecast of specific emissions by traffic regions. • Focus on both CO 2 and NO x emissions. • Forecast of climate impact effects for three scenarios up to the year 2100. Transport is considered to be a major contributor to emissions, resulting in a deterioration of local air quality and contributing to global climate change. The present paper focuses on how passenger flights departing from German airports contribute to global climate change. We describe in detail, how traffic forecasts for three scenarios entitled Reference, Free Play and Regulated Shift have been developed and how the resultant emissions have been quantified. Subsequently, we applied a climate model, providing insights into the very long-term climate effects under different assumptions on emissions up to the year 2100. The modelling framework shows that the development of emissions results from complex interactions of demand development and supply decisions, which highly influence the climate impact. With this paper, we show that an integrated, multi-disciplinary analysis can create valuable indicators and advice for transport policy decisions. [ABSTRACT FROM AUTHOR]

Lignocellulosic bioenergy crops are a potential option for climate mitigation and for meeting the targets of the Paris Agreement in Europe. The PopFor process-based model has been developed based on the earlier MiscanFor model and parameterised for poplar using data from a literature review in combination with experimental data on high performing clones Max 1, 3, 4 for extensively and intensively managed sites in Germany. PopFor needs comparatively few input data to provide accurate estimates of biomass yield. The parameters found allowed a good match to measured values. The best fit for bud emergence is 81 °days (base 5), with leaf emergence at 463 °days (base 5) and the temperature at which photosynthesis slows is 28 °C. Maximum radiation use efficiency was set to 2.9 gMJ−1. The air temperature threshold that kills crop was set at −37 °C with the number of days below this threshold that kills the crop set at 90 days. 30 days below wiltpoint was set as a threshold that kills the crop from drought. It was found that plant available water was the key explanatory variable in predicting yield and access to groundwater explained 97% of the yield variation between the sites. The results show that the model estimates the yield of poplar after the establishment phase with a mean difference of 0.27 DM t ha−1 y−1 (r2 0.99, n29, F = 4.18, p < 0.05 with RMSE = 19.68%). PopFor was shown to be an effective model for predicting yields under different soil conditions. Image 1 • New poplar model for predicting yield estimates on a local or larger scale. • PopFor needs only soil and weather data, no diameter or stem measurements. • PopFor accurately modelled yield for 2nd rotation and intensively managed 1st rotation poplar coppice. • PopFor parameters are widely applicable. • PopFor is a suitable tool for defining the most suitable areas for poplar bioenergy. [ABSTRACT FROM AUTHOR]

The main objective of this article is to reflect on the structure of the mobility and transport research landscape in Germany, in particular its current situation, its historic development and its future prospect. Thus, we describe its heterogeneity in terms of disciplinary characteristics and key objectives by identifying four academic subdivisions. We argue that this structure has developed differently from international discourse because of historical factors such as the dominance of the car for industrial politics, a strong political movement for the mitigation of climate change and specific funding structures. Furthermore, we discuss the reasons why German researchers do (not) participate in an international and Anglo-American language discourse. Against this background, we conclude with five conceptual suggestions for improved German transport and mobility research in the future: the need for (i) both fundamental and applied research, (ii) interdisciplinary work, (iii) experimental designs, (iv) a justification for both international and national language research, and (v) the creation of interdisciplinary research centres (e.g. Max Planck institutes). [ABSTRACT FROM AUTHOR]