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In Germany, emissions from drained organic soils contributed approximately 53.7 Mio. t of carbon dioxide equivalents (CO2-eq) to the total national greenhouse gas (GHG) emissions in 2021. In addition to restoration measures, shifting management practices, rewetting, or using peatlands for paludiculture is expected to significantly reduce GHG emissions. The effects of climate change on these mitigation measures remains to be tested. In a 2017 experimental field study on agriculturally used grassland on organic soil, we assessed the effects of rewetting and of predicted climate warming on intensive grassland and on extensively managed sedge grassland (transplanted Carex acutiformis monoliths). The testing conditions of the two grassland types included drained versus rewetted conditions (annual mean water table of − 0.13 m below soil surface), ambient versus warming conditions (annual mean air temperature increase of + 0.8 to 1.3 °C; use of open top chambers), and the combination of rewetting and warming. We measured net ecosystem exchange of CO2, methane and nitrous oxide using the closed dynamic and static chamber method. Here, we report the results on the initial year of GHG measurements after transplanting adult Carex soil monoliths, including the controlled increase in water level and temperature. We observed higher N2O emissions than anticipated in all treatments. This was especially unexpected for the rewetted intensive grasslands and the Carex treatments, but largely attributable to the onset of rewetting coinciding with freeze–thaw cycles. However, this does not affect the overall outcomes on mitigation and adaptation trends. We found that warmer conditions increased total GHG emissions of the drained intensive grassland system from 48.4 to 66.9 t CO2-eq ha−1 year−1. The shift in grassland management towards Carex paludiculture resulted in the largest GHG reduction, producing a net cooling effect with an uptake of 11.1 t CO2-eq ha−1 year−1. Surprisingly, we found that this strong sink could be maintained under the simulated warming conditions ensuing an emission reduction potential of − 80 t CO2-eq ha−1 year−1. We emphasize that the results reflect a single initial measurement year and do not imply the permanence of the observed GHG sink function over time. Our findings affirm that rewetted peatlands with adapted plant species could sustain GHG mitigation and potentially promote ecosystem resilience, even under climate warming. In a warmer world, adaptation measures for organic soils should therefore include a change in management towards paludiculture. Multi-year studies are needed to support the findings of our one-year experiment. In general, the timing of rewetting should be considered carefully in mitigation measures. [ABSTRACT FROM AUTHOR]

We shed new light on a long-standing question in political science: When confronted with costly policy choices, do citizens form their preferences using material (economic) concerns or other-regarding motivations, such as the distribution of costs, and how are these moderated by political ideology? Using the case of carbon taxation, a widely advocated policy solution to climate change, we conducted survey experiments in Germany and the United States to assess the relative importance of these forms of preferences. The results show that individuals are primarily concerned with how a carbon tax would affect their individual income. There are also important cross-national differences with high-income German respondents being more receptive to redistributive policy design, especially in contrast to high-income Democrats who significantly decrease support for carbon taxation. These findings highlight how the constituencies generated by new policies can significantly alter the distribution of mass support for action on emerging societal problems. [ABSTRACT FROM AUTHOR]

A rising number of climate cases is brought against governments, administrations, and companies in support of enhanced climate action. This is the second of two articles that aim to scrutinise climate litigation as a social process and as a driver towards deep decarbonisation from the perspectives of law, social, and political sciences. Working towards more systematic research on societal embedding and dynamics of climate litigation, we further develop and test two analytical tools, the Social Plausibility Assessment Framework and the Global Opportunity Structure, at two levels. While the first article presented these analytical tools and analysed general developments in climate litigation in their societal context at an overarching level, this second article zooms into a case-specific level and examines two landmark decisions, Neubauer and others v Germany and Milieudefensie and others v Shell. The analytical approach generates valuable insights about the conditions and effects of climate litigation on both levels. Our results show that climate litigation is a significant driver towards deep decarbonisation that is shaped by, and continuously shapes, legal, socio-political, economic, and scientific scripts and repertoires that enable novel forms of societal agency. [ABSTRACT FROM AUTHOR]

Mountain forests are plant diversity hotspots, but changing climate and increasing forest disturbances will likely lead to far‐reaching plant community change. Projecting future change, however, is challenging for forest understory plants, which respond to forest structure and composition as well as climate. Here, we jointly assessed the effects of both climate and forest change, including wind and bark beetle disturbances, using the process‐based simulation model iLand in a protected landscape in the northern Alps (Berchtesgaden National Park, Germany), asking: (1) How do understory plant communities respond to 21st‐century change in a topographically complex mountain landscape, representing a hotspot of plant species richness? (2) How important are climatic changes (i.e., direct climate effects) versus forest structure and composition changes (i.e., indirect climate effects and recovery from past land use) in driving understory responses at landscape scales? Stacked individual species distribution models fit with climate, forest, and soil predictors (248 species currently present in the landscape, derived from 150 field plots stratified by elevation and forest development, overall area under the receiving operator characteristic curve = 0.86) were driven with projected climate (RCP4.5 and RCP8.5) and modeled forest variables to predict plant community change. Nearly all species persisted in the landscape in 2050, but on average 8% of the species pool was lost by the end of the century. By 2100, landscape mean species richness and understory cover declined (−13% and −8%, respectively), warm‐adapted species increasingly dominated plant communities (i.e., thermophilization, +12%), and plot‐level turnover was high (62%). Subalpine forests experienced the greatest richness declines (−16%), most thermophilization (+17%), and highest turnover (67%), resulting in plant community homogenization across elevation zones. Climate rather than forest change was the dominant driver of understory responses. The magnitude of unabated 21st‐century change is likely to erode plant diversity in a species richness hotspot, calling for stronger conservation and climate mitigation efforts. [ABSTRACT FROM AUTHOR]

To stay within a 'well below 2°C' climate change track, the Paris Agreement and goal 13 of the Sustainable Development Goals (SDGs) call for climate action – a global decrease in Green House Gas (GHG) emissions. Arguments in this study are derived from the hypothesis that a collective identity among the EU states would foster collective actions toward reducing global warming. Thus, the objective of this study is to explore how different EU countries (Poland, Italy, and Germany) employ three decarbonization pillars: waste recycling, eco-innovation, and policy innovation (WEP) as a yardstick to mitigate global warming and attain the EU's 'net-zero' emissions by 2050. The study also utilizes annual data collected from the Eurostat indicator from 2014 to 2020. The findings reveal that Germany has the most successful average recycling rate in Europe; 65.5% of the country's domestic waste is either recycled or reused. On the other hand, Poland is a low performer in eco-innovation. Additionally, an analysis of policy regulations reveals that both Germany and Italy can comply with the policy and regulations of the EU on carbon neutrality. At the same time, Poland, on the other hand, lacks the commitment to carbon neutrality due to its reliance on carbon-intensive coal. Therefore, this study recommends translating EU climatic laws in their simplest forms into local laws. More so, citizens' behaviour will be further influenced toward environmental sustainability by this collective mindset. [ABSTRACT FROM AUTHOR]

Germany is known as a leader in energy transition, but the country keeps falling short of meeting stated objectives. While attention has been high on climate change related policy leadership, the competing domestic alliances in the field of energy transition have received scant attention. In Germany, the strong momentum of the conversion to renewable energy has been stalled in the second half of the 2010s. Enabled by an increasing weight of neoliberal economic concerns, traditional energy coalitions have managed to reshape the path of energy transition. In this article three competing discourse coalitions are introduced to examine their constituencies and projects in the field of energy and politics. It focuses on radical ecological forces around the Öko-Institut, environmental modernization capacities linked to Green Budget Germany and fossil interest groups intersecting with neoliberal academic and partisan think tanks. As such, the article opens a view on multiple contestations over Germany's Energiewende. [ABSTRACT FROM AUTHOR]

The National Climate Initiative (NKI) in Germany provides a strong incentive for local governments to apply for funding to engage in climate protection activities. Yet, the latest evaluation of the NKI confirms that there is a great disparity in the distribution of funding across regions. Taking this regional fragmentation as a starting point, we ask the following: How can we explain disparity in the amount of funding across counties and cities? We draw on climate policy literature pointing to the role of socioeconomic and political determinants and the settlement structure to answer this question. We study all 400 cities and counties to test hypotheses concerning disparity in the likelihood and amount of climate funding, using data from the German Ministry for the Environment and further regional statistics. Running different multilevel regression models, we show that local climate funding is more likely in cities and more urbanized counties than in rural counties with less population and oftentimes also with less young and educated people. We argue that despite the increasing number of local governments getting active in climate protection in Germany, there is important unused potential for climate change mitigation in rural counties. Therefore, we conclude by proposing a new research agenda focusing on climate change mitigation in rural areas. [ABSTRACT FROM AUTHOR]

A growing number of court cases are being brought against governments, administrations, and corporations in support of enhanced climate action. This is the first of two articles that examine climate litigation as a social process and potential driver of deep decarbonisation from a perspective that combines legal, social, and political science. Contributing to an emerging interdisciplinary research agenda on the dynamics and effects of climate litigation and on its societal embeddedness, we present and test two analytical tools, the Social Plausibility Assessment Framework and the Global Opportunity Structure for Climate Action. The first article introduces these analytical tools, and applies them to assess the overall evolution of climate litigation and identify developments in its legal and societal context that enable or constrain future driver dynamics. Based on this assessment, we conclude that climate litigation constitutes an important but on its own insufficient driver of deep decarbonisation, which is shaped by, and continuously shapes, legal, socio-political, economic, and scientific scripts and repertoires that enable novel forms of societal agency. The second article further operationalises and illustrates the approach by zooming in on a case-specific level and examining two recent landmark decisions in the Netherlands and Germany. [ABSTRACT FROM AUTHOR]

Aims: Soil organic carbon (SOC) stocks of croplands can be enhanced by targeted management, which boosts soil fertility and contributes to climate change mitigation. One SOC sequestration option is adopting cover crops. The aim of this study was to quantify the SOC sequestration potential of cover crops in Germany. Methods: We simulated SOC scenarios on 1,267 cropland sites with site-specific management data using an SOC model ensemble consisting of RothC and C-TOOL. A new method was developed to estimate carbon input from cover crops that included the effects of climate, sowing date and species on cover crop biomass production. Results: The recent cover crop area could be tripled to 30% of arable land in Germany. This would enhance total carbon input by 12% and increase SOC stocks by 35 Tg within 50 years, corresponding to an annual increase of 0.06 Mg C ha-1, 2.5 Tg CO2 or 0.8 per mill of current SOC stocks in 0–30 cm depth. On sites with cover crops, 0.28–0.33 Mg C ha-1 a-1 would be accumulated within 50 years. Our simulations predicted that even if the full potential for cover crop growth were realised, there would still be a decline in SOC stocks in German croplands within 50 years due to the underlining negative SOC trend. Conclusions: Cover crops alone cannot turn croplands from carbon sources to sinks. However, growing them reduces bare fallow periods and SOC losses and thus is an effective climate change mitigation strategy in agriculture. [ABSTRACT FROM AUTHOR]

Germany's health care footprint accounts for 5.2% of the national emissions footprint which results in 0.71 tons of CO2 emission per capita. Thus, the health sector has a responsibility to take climate action. Surgery is a resource-intensive health care activity, requiring expensive equipment, sterilization procedures, advanced operative technologies, and obligatory life support systems. We spotlight the situation in a department of ophthalmology with frequent anesthesia services and highly standardized procedures. This narrative review discusses high-impact actions which result in a major reduction of the CO2 footprint according to the global road map for health care decarbonization, considering both the ophthalmic and anesthesiologic point of view. [ABSTRACT FROM AUTHOR]

To successfully battle climate change, it is crucial to reach people across political camps and national borders. Research from dual-party systems indicates that climate change communication is most effective when it addresses how climate action promotes recipients' political values. Yet, to our knowledge, there is no such evidence from multi-party systems. To fill this gap, we conducted three studies in two Central European, German-speaking countries: Germany and Austria. In Study 1, we framed conservative and liberal climate protection messages using values from Schwartz's Theory of Basic Human Values. Liberals agreed more with the liberally framed than with the conservatively framed climate protection message. In Study 2, we framed the climate protection message based on moral foundations. Conservative participants agreed more with the conservatively framed climate protection message than with the liberally framed one. Study 3 integrated values from multiple frameworks, and ultimately conservatives as well as liberals agreed more to climate protection statements that touched on values reflecting their political ideology. Thus, empirical findings from dual-party systems hold for countries with more than two parties. [ABSTRACT FROM AUTHOR]

Adverse consequences of climate change often affect people and places far away from those that have the greatest capacity for mitigation. Several correlational and some experimental studies suggest that the willingness to take mitigation actions may diminish with increasing distance. However, the empirical findings are ambiguous. In order to investigate if and how socio-spatial distance to climate change effects plays a role for the willingness to engage in mitigation actions, we conducted an online experiment with a German population sample (n = 383). We find that the willingness to sign a petition for climate protection was significantly reduced when a person in India with a name of Indian origin was affected by flooding, as compared to a person in Germany with a name of German origin. Distance did not affect donating money to climate protection or approving of mitigation policies. Our results provide evidence for the existence of a negative effect of distance to climate change consequences on the willingness to engage in low-cost mitigation actions. Investigating explanations for such an effect, we find that it can be attributed to the spatial rather than the social dimension of distance. Moreover, we find some cautious evidence that people with strong racist attitudes react differently to the distance manipulations, suggesting a form of environmental racism that could also reduce mitigation action in the case of climate change. [ABSTRACT FROM AUTHOR]

Simple Summary: Beef production is criticized for its contribution to global warming and its use of human-edible food as feed and hence needs to innovate. Relying on three case studies of beef production systems in Belgium, France, and Germany, we test, using the single-farm model FarmDyn, the interest of fast rotational grazing associated (redesign scenarios) or not (FRG scenarios) to crossbreeding strategies as innovation. The redesign scenarios are adapted to local conditions using early-maturing beef breeds on a French farm or Belgian Blue breeds in a German dairy system and a Belgian suckler cow system becoming, in this last type, a growing and fattening system. Fast rotational grazing induced a higher profit through cheaper feed but an increased workload in pasture management compared to the baseline situation. Beef production from crossbred dairy cows reduces the global warming potential of the systems because of the share of the environmental load with milk production. Crossbreeding with early-maturing breeds, in the French type, has little impact on global warming. The feed-food competition diminished by adapting the stocking rate to the grassland production potential and feeding of by-products. In the future, these simulations should be validated by field trials and a larger diversity of farms. In the context of a growing population, beef production is expected to reduce its consumption of human-edible food and its contribution to global warming. We hypothesize that implementing the innovations of fast rotational grazing and redesigning existing production systems using crossbreeding and sexing may reduce these impacts. In this research, the bio-economic model FarmDyn is used to assess the impact of such innovations on farm profit, workload, global warming potential, and feed-food competition. The innovations are tested in a Belgian system composed of a Belgian Blue breeder and a fattener farm, another system where calves raised in a French suckler cow farm are fattened in a farm in Italy, and third, a German dairy farm that fattens its male calves. The practice of fast rotational grazing with a herd of dairy-to-beef crossbred males is found to have the best potential for greenhouse gas reduction and a reduction of the use of human-edible food when by-products are available. Crossbreeding with early-maturing beef breeds shows a suitable potential to produce grass-based beef with little feed-food competition if the stocking rate considers the grassland yield potential. The results motivate field trials in order to validate the findings. [ABSTRACT FROM AUTHOR]

Bayesian affect control theory is a model of affect-driven social interaction under conditions of uncertainty. In this paper, we investigate how the operationalization of uncertainty in the model can be related to the disruption of social orders—societal pressures to adapt to ongoing environmental and technological change. First, we study the theoretical tradeoffs between three kinds of uncertainty as groups navigate external problems: validity (the predictability of the environment, including of other agents), coherence (the predictability of interpersonal affective dynamics), and dependence (the predictability of affective meanings). Second, we discuss how these uncertainty tradeoffs are related to contemporary political conflict and polarization in the context of societal transitions. To illustrate the potential of our model to analyze the socio-emotional consequences of uncertainty, we present a simulation of diverging individual affective meanings of occupational identities under uncertainty in a climate change mitigation scenario based on events in Germany. Finally, we sketch a possible research agenda to substantiate the novel, but yet mostly conjectural, ideas put forward in this paper. [ABSTRACT FROM AUTHOR]

Purpose: Flower strips have been shown to increase insect biodiversity and improve agricultural yields through increased pollination and pest predation. Less is known about their potential to increase soil organic carbon (SOC). We aimed to investigate the biomass production and SOC sequestration potential of flower strips as a sustainable management option of temperate agricultural soils. Methods: 23 flower strips across varying soil types and climatic regions in Germany were sampled for aboveground and belowground peak biomass in order to estimate the annual carbon input to the soil. Those were used as 23 scenarios to model the potential SOC sequestration of the flower strips compared to a business-as-usual scenario for 1533 sites of the German Agricultural Soil Inventory using the RothC model. Results: On average, flower strips sequestered 0.48 ± 0.36 Mg C ha−1 year−1 in the initial 20-year period after establishment. Converting 1 % of the total German cropland area into flower strips would thus lead to a mitigation of 0.24 Tg CO2 year−1, which equals 0.4 % of current agricultural greenhouse gas emissions in Germany. We found a negative correlation between C sequestration rate and the number of plant species in the flower strips, mainly related to grasses outcompeting herbaceous species. Conclusion: Flower strips are one overlooked option for increasing SOC stocks of croplands that has multiple benefits for agro-ecosystems. However, within a flower strip it might not be possible to maximise both plant biodiversity and SOC sequestration. [ABSTRACT FROM AUTHOR]

Background: Forestry plays a major role in climate change mitigation. However, which intensity of logging is best suited for that task remains controversial. We contribute to the debate by quantitatively analyzing three different forest management scenarios in Germany—a baseline scenario which represents a continuation of current forest management practice as well as an intensive and an extensive logging scenario. We assess whether increased carbon storage in wood products and substitution of other emission-intensive materials can offset reduced carbon stocks in the forest due to increased harvesting. For that, we calculate annual required displacement factors (RDF)—a dimensionless quantity that indicates the minimal displacement factor (DF) so that intensive forestry outperforms extensive forestry from a climate perspective. Results: If the intensive forest management scenario is included in the comparison, the RDF starts off with relatively high values (1 to 1.5) but declines over time and eventually even reaches negative values. Comparing the extensive scenario to a baseline yields RDF values between 0.1 and 0.9 with a slightly increasing trend. Compared to RDFs, expected future DFs are too low to favour the intensive forestry scenario and too high to favour the extensive forestry scenario, during the first 25 years of the modeling period. However, towards the end of the modeling period, the relationship between DFs and RDF is turned around in both comparisons. In the comparison between intensive and extensive forest management RDF values are very similar to future DF trajectories. Conclusion: RDFs are a useful tool for comparing annual climate impacts of forest growth scenarios and can be used to benchmark material and energy substitution effects of wood. Our results indicate that the baseline scenario reflects an effective compromise between carbon stocks in the forest and carbon displacement by wood use. For a longer modeling period, however, this might not be the case. Which of the alternative scenarios would be best suited for climate change mitigation is heavily dependent on future DF trajectory. Hence, our findings highlight the necessity of robust projections of forest dynamics and industry decarbonization pathways. [ABSTRACT FROM AUTHOR]

One of the most promising climate change mitigation technologies is green hydrogen, which contributes to a drastic reduction in the share of fossil fuels and thus to climate protection. Eastern Germany, as a historically grown energy and industrial location, has excellent conditions for the development of a hydrogen economy. In addition to the relevant utilization potential already existing in the industrial and urban centres, there is also enormous production potential for renewable electricity on the coast in the north as well as the relevant hydrogen storage and transport capacities. In view of the dynamic development of recent years and the necessary implementation perspective, the expansion of import and transit pipelines to the European hydrogen backbone is imperative to meet the enormous demand for green hydrogen for the region, which greatly exceeds the production capacities. To maxmize the potential, society must coordinate transfer strategies, legal frameworks and funding opportunities, which must be synchronized and adapted regionally as well as nationally and EU-wide. [ABSTRACT FROM AUTHOR]

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]

The implementation of oxyfuel carbon capture and storage technologies in combination with use of alternative fuels comprising high biogenic shares is promoted as an attractive climate change mitigation option for the cement sector to achieve low or even negative carbon emissions. Here, we perform a prospective life cycle assessment of two state-of-the art cement plants, one in Sweden and one in Germany, under conventional and retrofitted oxyfuel conditions considering alternative fuel mixes with increasing bio-based fractions of forest residues or dedicated bioenergy crops. The analysis also considers effects of the projected changes in the electricity systems up to 2050. Retrofitting the cement plants to oxyfuel reduces climate change impacts between 74 and 91%, while with additional use of biomass as alternative fuel the cement plants reach negative emission between − 24 and − 169 gCO2eq. kgclinker−1, depending on operational condition, location, and biomass type. Additional emission reduction of − 10 (Sweden) and − 128 gCO2eq. kgclinker−1 (Germany) are expected from the decarbonization of the future electricity systems. Retrofitting the cement plants to oxyfuel conditions shows trade-offs with other environmental impacts (e.g., human toxicity, water and energy depletion), which are partially offset with projected changes in electricity systems. Our results illustrate the large climate change mitigation potential in the cement sector that can be achieved by the implementation of oxyfuel carbon capture and storage and biomass use as alternative fuel. [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]

Strong public support is a prerequisite for ambitious and thus costly climate change mitigation policy, and strong public concern over climate change is a prerequisite for policy support. Why, then, do most public opinion surveys indicate rather high levels of concern and rather strong policy support, while de facto mitigation efforts in most countries remain far from ambitious? One possibility is that survey measures for public concern fail to fully reveal the true attitudes of citizens due to social desirability bias. In this paper, we implemented list-experiments in representative surveys in Germany and the United States (N = 3620 and 3640 respectively) to assess such potential bias. We find evidence that people systematically misreport, that is, understate their disbelief in human caused climate change. This misreporting is particularly strong amongst politically relevant subgroups. Individuals in the top 20% of the income distribution in the United States and supporters of conservative parties in Germany exhibit significantly higher climate change skepticism according to the list experiment, relative to conventional measures. While this does not definitively mean that climate skepticism is a widespread phenomenon in these countries, it does suggest that future research should reconsider how climate change concern is measured, and what subgroups of the population are more susceptible to misreporting and why. Our findings imply that public support for ambitious climate policy may be weaker than existing survey research suggests. [ABSTRACT FROM AUTHOR]

Proliferative kidney disease (PKD) caused by the myxozoan parasite Tetracapsuloides bryosalmonae is an emerging salmonid disease implicated in recent declines in salmonid populations. Laboratory experiments have shown that the clinical symptoms of PKD exacerbate with increasing temperature. However, empirical evidence for a relationship between climate change and PKD driven declines in wild salmonid stocks is scarce.The current study uses both empirical data and ecological niche modelling to extrapolate future changes in temperature and precipitation on the spread of PKD in relation to changes in suitability of rivers for its primary bryozoan and secondary salmonid hosts.A 20‐year dataset on brown trout density using standardised method shows a decline of more than 50% in the population of the river Wutach, south‐western Germany at 536–755 m elevation. The decline coincides with higher prevalence of PKD. This decline was temperature related and driven by reduced local survival of parr to yearlings. Kidney hyperplasia was highest at low elevations and correlated negatively with trout density.Niche models based on state‐wide data show strong overlap in the areas suitable for T. bryosalmonae and its primary bryozoan hosts, and a strong link with temperature. Projections based on moderate to high emission‐case climate change scenarios predict a 50%–82% decrease in the area suitable for salmonids within this century, linked to PKD.The empirical data identify temperature‐mediated PKD as the underlying cause of the population decline. This relationship was corroborated by the niche modelling results. The highest losses are expected in projected salmonid suitable areas where salmonid habitats currently overlap with areas suitable for T. bryosalmonae.With ongoing climate change, both current and future populations are at severe risk to T. bryosalmonae and its associated disease PKD. Conservation efforts of salmonid stocks are dependent on climate mitigation and measures to help salmonids adapt to the disease. [ABSTRACT FROM AUTHOR]

Germany's greenhouse gas emissions have declined by 35% since 1990, and the national policy ambition is to become largely carbon‐neutral by 2050. A change of the industrial landscape and a partial transformation of energy supply have contributed to reductions so far, but for deep reductions, a deep transformation of the country's industrial metabolism is needed. While energy efficiency is well established, the same cannot be said for material efficiency, which includes product light‐weighting, lifetime extension, more intense use, and value retention strategies like higher recycling rates, remanufacturing, and reuse. Sector‐specific research showed substantial energy and emissions savings potentials of material efficiency, but the overall material efficiency potential for most world economies, including Germany, is unknown. We applied an open‐source and modular dynamic material flow analysis model of the transformation of passenger vehicles, residential buildings, and commercial and service buildings in Germany (together ca. 50% of national greenhouse gases) to a material‐efficient system, covering the time span 2016–2060. The potential impact of the above‐mentioned material efficiency strategies was studied for the climate‐relevant materials concrete, steel, timber, aluminum, and plastics. Once the potentials of energy‐efficient products, electrification of end‐use sectors, and energy system transformation are seized, supply and demand side material efficiency and sufficiency can reduce remaining 2050 emissions by an additional 19–34 % (passenger vehicles), 27–31% (residential buildings), and 14–19% (non‐residential buildings). The 2016–2050 cumulative savings can be up to 750 Mt (million metric tons) CO2‐eq. Material efficiency can be a key contributor to deep emissions cuts like a 95% target. This article met the requirements for a gold‐gold JIE data openness badge described at http://jie.click/badges. [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]

Forest management affects carbon sequestration (mitigation) and resilience of forest ecosystems (adaptation) under climate change. Therefore, the efforts to integrate these two approaches have been made by the political arrangements to seek the synergy effects and deal with trade-offs. To study the state of the art linkages and forest policies to realize both adaptation and mitigation, we systematically review the literature highlighting the topic (136 publications) and outline two different approaches from Germany and Japan as countries with substantial forest resources and high influences on international forest policies and wood trade. We identify three linkages: (1) an ecosystem (based) approach assuming that a resilient ecosystem (adaptation), has high potential as a carbon sink (mitigation), (2) a sustainable forest management (SFM) aiming for enhancing forests' resilience and carbon sink potential simultaneously, and (3) a cross-sectoral approach generating synergies among multiple sectors of agriculture, forestry, urban design, and nature conservation. We find that a significant objective is still SFM for sustaining the forest area andwood production, where SFM examples in Germany and Japan exemplify contributions to carbon sinks and ongoing disaster risk management, respectively. Overall, the current differentiated objectives of SFM do not underpin the twofold approach and their synergy effects. [ABSTRACT FROM AUTHOR]

In order to examine the impact of different Power‐to‐X technologies on the transformation of the German energy system and meeting the climate change mitigation goals, a cross‐sectoral energy system model was developed. The results show that Power‐to‐X will be essential for a successful energy transition. Especially in applications where high energy densities are required and only few other options for defossilization exist, Power‐to‐X technologies become essential. [ABSTRACT FROM AUTHOR]

Crop residue exploitation for bioenergy can play an important role in climate change mitigation without jeopardizing food security, but it may be constrained by impacts on soil organic carbon (SOC) stocks, and market, logistic and conversion challenges. We explore opportunities to increase bioenergy potentials from residues while reducing environmental impacts, in line with sustainable intensification. Using the case study of North Rhine‐Westphalia in Germany, we employ a spatiotemporally explicit approach combined with stakeholder interviews. First, the interviews identify agronomic and environmental impacts due to the potential reduction in SOC as the most critical challenge associated with enhanced crop residue exploitation. Market and technological challenges and competition with other residue uses are also identified as significant barriers. Second, with the use of agroecosystem modelling and estimations of bioenergy potentials and greenhouse gas emissions till mid‐century, we evaluate the ability of agricultural management to tackle the identified agronomic and environmental challenges. Integrated site‐specific management based on (a) humus balancing, (b) optimized fertilization and (c) winter soil cover performs better than our reference scenario with respect to all investigated variables. At the regional level, we estimate (a) a 5% increase in technical residue potentials and displaced emissions from substituting fossil fuels by bioethanol, (b) an 8% decrease in SOC losses and associated emissions, (c) an 18% decrease in nitrous oxide emissions, (d) a 37% decrease in mineral fertilizer requirements and emissions from their production and (e) a 16% decrease in nitrate leaching. Results are spatially variable and, despite improvements induced by management, limited amounts of crop residues are exploitable for bioenergy in areas prone to SOC decline. In order to sustainably intensify crop residue exploitation for bioenergy and reconcile climate change mitigation with other sustainability objectives, such as those on soil and water quality, residue management needs to be designed in an integrated and site‐specific manner. [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]

The successful implementation of the Paris Agreement requires substantial energy policy change on the national level. In national energy policy-making, climate change mitigation goals have to be balanced with arguments on other national energy policy goals, namely limiting cost and increasing energy security. Thus far, very little is known about the relative importance of these goals and how they are related to political partisanship. In order to address this gap, we focus on parliamentary discourse around low-carbon energy futures in Germany over the past three decades and analyze the relative importance of, and partisanship around, energy policy goals. We find that the political discourse revolves around four, rather than three, goals as conventionally assumed; improving the competitiveness of the national energy technology industry is not only an additional energy policy goal, it is also highly important in the political discourse. In general, the relative importance of these goals is rather stable over time and partisanship around them is limited. Yet, a sub-analysis of the discourse on renewable energy technologies reveals a high level of partisanship, albeit decreasing over time. Particularly, the energy industry goal's importance increases while its partisanship vanishes. We discuss how these findings can inform future energy policy research and provide a potential inroad for more ambitious national energy policies. Key policy insights In addition to the three classic goals of energy policy (limiting cost, securing access and reducing the environmental burden) we identify a fourth policy goal: strengthening the national energy technology industry Conformity between the three classical energy and the industrial policy goals is a key driver explaining policy change For renewable energy technologies, partisanship around this fourth goal is lower than around other goals and decreases over time as innovation allows these technologies to increasingly correspond to policy-makers' high-level goals Extant research underestimates the importance of industry policy goals, but overestimates environmental co-benefits of low-carbon energy options Paradigmatic policy change in Germany did not depend on top-down shifts in high-level policy goals but was driven by lower-level technology-specific goals [ABSTRACT FROM AUTHOR]

There is limited evidence of temporal changes in the association between air temperature and the risk of cause-specific cardiovascular [CVD] and respiratory [RD] mortality. We explored temporal variations in the association between short-term exposures to air temperature and non-accidental and cause-specific CVD and RD mortality in the 15 largest German cities over 24 years (1993–2016) using time-stratified time series analysis. We applied location-specific confounder-adjusted Poisson regression with distributed lag non-linear models with a lag period of 14 days to estimate the temperature–mortality associations. We then pooled the estimates by a multivariate meta-analytical model. We analysed the whole study period and the periods 1993–2004 and 2005–16, separately. We also carried out age- and sex-stratified analysis. Cold and heat effects are reported as relative risk [RR] at the 1st and the 99th temperature percentile, relative to the 25th and the 75th percentile, respectively. We analysed a total of 3,159,292 non-accidental, 1,063,198 CVD and 183,027 RD deaths. Cold-related RR for CVD mortality was seen to rise consistently over time from 1.04 (95% confidence interval [95% CI] 1.02, 1.06) in the period 1993–2004 to 1.10 (95% CI 1.09, 1.11) in the period 2005–16. A similar increase in cold-related RR was also observed for RD mortality with risk increasing from 0.99 (95% CI 0.96, 1.03) to 1.07 (95% CI 1.03, 1.10). Cold-related ischemic, cerebrovascular, and heart failure mortality risk were seen to be increasing over time. Similarly, COPD, the commonly speculated driver of heat-related RD mortality was found to have a constant heat-related risk over time. Males were increasingly vulnerable to cold with time for all causes of death. Females showed increasing sensitivity to cold for CVD mortality. Our results indicated a significant increased cold and heat vulnerability of the youngest age-groups (<64) to non-accidental and RD mortality, respectively. Similarly, the older age group (>65) were found to have significantly increased susceptibility to cold for CVD mortality. We found evidence of rising population susceptibility to both heat- and cold-related CVD and RD mortality risk from 1993 to 2016. Climate change mitigation and targeted adaptation strategies might help to reduce the number of temperature-related deaths in the future. • Temporal variations temperature-cause-specific mortality association was explored. • Evidence of rising population susceptibility to both heat- and cold-related mortality. • COPD, the commonly speculated driver of heat-related respiratory mortality, found to have a constant heat-related risk over time. • Climate change mitigation and targeted adaptation strategies recommended. [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]

Company cars have received considerable attention because of their partial tax-exemption and the changes in travel behaviour they stimulate, including car model choices, distances driven, and car ownership patterns. This paper is the first to present evidence on actual transport behaviour change, based on mobility and fuel diaries, and comparing a sample of 624 company cars and 9328 private cars in Germany. Analysis confirms that company cars belong to the more heavily motorized car segments (with an average 97 kW, as opposed to 79 kW of private cars), and are driven more than private cars (24,672 km per year, compared to 12,828 km per year for private cars). Company car benefits also increase average household vehicle numbers by 25%. Results show that it is imperative to distinguish company cars of company owners relative to those driven by employees, as negative externalities increase significantly where company cars are used by the latter. Abolishing company car benefits could significantly reduce emissions from passenger road transport and stimulate change in the country's automotive industries towards a lower-carbon path. As Germany is not currently on track to meet its climate mitigation targets, this would be a timely policy shift. Key policy insights Company car benefits increase transport demand, car ownership, and average vehicle fleet engine power. These effects are particularly relevant for employees. Company cars have, in spite of their larger size and greater engine power, a (modestly) better fuel economy than private cars, possibly because they represent more recent and hence more efficient car models. A policy focus on vehicle fuel efficiency improvements will fail to reduce the German car fleet's CO2 emissions to a sustainable level. Abolishing company car benefits could yield a significant reduction in GHG emissions from passenger road transport. Company car subsidies are an out-dated mode of support for the fossil-fuel based automotive industry. [ABSTRACT FROM AUTHOR]

The objective of this study is to quantify the contribution of the German forestry to climate change mitigation and to calculate the associated costs at the national level. For that, the forest and harvested wood products carbon pools are considered as well as energy and material substitution. We compare five different scenarios, each referring to an alternative level of timber harvests (due to changing rotation lengths or setting aside of forest areas). The study shows that enhancing the use of wood products at the expense of other materials, such as steel, plastic or concrete, can have a substantial impact on the overall carbon balance. [ABSTRACT FROM AUTHOR]

The Paris Agreement calls on all nations to pursue efforts to contribute to limiting the global temperature increase to 1.5 °C above pre-industrial levels. However, due to limited global, regional and country-specific analysis of highly ambitious GHG mitigation pathways, there is currently a lack of knowledge about the transformational changes needed in the coming decades to reach this target. Through a meta-analysis of mitigation scenarios for Germany, this article aims to contribute to an improved understanding of the changes needed in the energy system of an industrialized country. Differentiation among six key long-term energy system decarbonization strategies is suggested, and an analysis is presented of how these strategies will be pursued until 2050 in selected technologically detailed energy scenarios for Germany. The findings show, that certain strategies, including the widespread use of electricity-derived synthetic fuels in end-use sectors as well as behavioral changes, are typically applied to a greater extent in mitigation scenarios aiming at high GHG emission reductions compared to more moderate mitigation scenarios. The analysis also highlights that the pace of historical changes observed in Germany between 2000 and 2015 is clearly insufficient to adequately contribute to not only the 1.5 °C target, but also the 2 °C long-term global target. [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]

Numerous studies have begun to tackle the social and cultural dimensions of perceiving and framing climate change. Scholars from geography and environmental psychology in particular have started to highlight the importance of so-called place-based approaches to studying regional and local framings of climate change. This paper stands in this tradition. It reports on findings derived from a nationwide survey of perceptions of and reactions to extreme weather events and interviews conducted with inhabitants of three islands in the coastal region of North Frisia (Germany). Coastal dwellers understand climate change through the lens of local and regional experiences of meteorological phenomena, seasonal changes, knowledge of the sea, and changes in local flora and fauna. Our detailed ecolinguistic analysis revealed six prevailing conceptual metaphors: Climate change is an enemy, preventing climate change is fight/war, climate change is punishment for human sins, climate change is overheating/heat, climate change is hot air/hoax and climate change is eco-dictatorship. These metaphors were used to make sense of climate change at the regional level and provide insights into place-based social and cultural conceptualisations of climate change. An understanding of these meanings should feed into developing more grounded climate change adaptation and mitigation strategies in coastal regions. [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]

The United Nations Framework Convention on Climate Change (UNFCCC) confers an obligation on developed states to lead in mitigation. This obligation challenges traditional conceptions of the modern state by calling forth a more outward looking state that is able to serve both the national and international communities in the service of global climate protection. Yet, the more skeptical theories of the ecological state suggest that climate leaders will only emerge if they can connect their climate strategy to the traditional state imperatives of economic growth or national security. How the governments of Germany and Norway, both relative climate leaders with ongoing fossil-fuel dependencies, have legitimated their climate policies and diplomacy is examined through a comparative discourse analysis. While both governments rely heavily on discourses of Green growth, they also construct national identities and international role conceptions that serve purposes beyond themselves. [ABSTRACT FROM PUBLISHER]