Creating common ground among research groups is a prerequisite for scientifically sound case study research, especially in multi-national and multi-disciplinary research projects. Therefore, this paper proposes a new procedure for case study selection: stochastic cognitive mapping (sCM). sCM complements the previously illustrated conceptual content cognitive mapping (3CM) with email enquiry on concepts and their interconnections, simple multi-attribute rating and stochastic estimation of priorities. The procedure was applied to select case studies in a study on the role of community-based initiatives (CBIs) in societal change towards sustainability. The procedure performed well, based on project members’ evaluations, and enabled them to consistently identify a map and ranked list of criteria for selecting case initiatives. Researchers of the project had two to some extent exclusive orientations towards case selection: sampling and searching strategies, i.e. emphasis on the representativeness of a case set or on the features that interesting and useful study cases should possess. Strategies were integrated and CBIs selected through the sequence of snowball, random, and purposive samplings. Moreover, the method and the criteria list are adaptable to support comparable studies across diverse contexts.

There is a growing recognition that a transition to a sustainable low-carbon society is urgently needed. This transition takes place at multiple and complementary scales, including bottom-up approaches such as community-based initiatives (CBIs). However, empirical research on CBIs has focused until now on anecdotal evidence and little work has been done to quantitatively assess their impact in terms of greenhouse gas (GHG) emissions. In this paper, we analyze 38 European initiatives across the food, energy, transport, and waste sectors to address the following questions: How can the GHG reduction potential of CBIs be quantified and analyzed in a systematic manner across different sectors? What is the GHG mitigation potential of CBIs and how does the reduction potential differ across domains? Through the comparison of the emission intensity arising from the goods and services the CBIs provide in relation to a business-as-usual scenario, we present the potential they have across different activities. This constitutes the foundational step to upscaling and further understanding their potential contribution to achieving climate change mitigation targets. Our findings indicate that energy generation through renewable sources, changes in personal transportation, and dietary change present by far the highest GHG mitigation activities analyzed, since they reduce the carbon footprint of CBI beneficiaries by 24%, 11%, and 7%, respectively. In contrast, the potential for some activities, such as locally grown organic food, is limited. The service provided by these initiatives only reduces the carbon footprint by 0.1%. Overall, although the proliferation of CBIs is very desirable from a climate change mitigation perspective it is necessary to stress that bottom-up initiatives present other important positive dimensions besides GHG mitigation. These initiatives also hold the potential of improving community resilience by strengthening local economies and enhancing social cohesion.

italianoLe conseguenze del cambiamento climatico globale sono sempre piu evidenti, e la stragrande maggioranza degli esperti concorda sul fatto che queste siano in gran parte causate da attivita antropiche. Diversi programmi internazionali sono stati implementati negli ultimi decenni a favore della mitigazione dei cambiamenti climatici. Nonostante cio, i risultati attesi da parte delle istituzioni sono ancora fuori portata. Contemporaneamente, la societa ha visto una significativa proliferazione di “Iniziative di Comunita” (Cbi), fondate sulla partecipazione individuale volontaria e volte a favorire una transizione sostenibile. Alcuni studiosi sostengono che tali attivita bottom-up possono dare risultati migliori in termini di sostenibilita rispetto a politiche top-down. Tuttavia, un quadro teorico-metodologico per una stima quantitativamente robusta del contributo portato dalle Cbi nell’alleviare la pressione antropica sull’ambiente non e mai stato ampiamente elaborato. Gli obiettivi di questo lavoro sono tre: elaborare una lettura problematizzante riguardo le principali limitazioni inerenti la valutazione d’impatto ambientale delle Cbi; definire un quadro teorico e metodologico semplice e sufficientemente esaustivo per tale valutazione; discutere alcuni risultati preliminari di particolare interesse relativi a singoli casi specifici analizzati durante il lavoro del progetto di ricerca europeo Towards European Societal Sustainability (FP7 Tess – Grant Agreement No. 603705). EnglishMeasuring the environmental impact of grassroots initiatives: a preliminary reflection about data availability and methodological limitations. – The consequences of global climate change are increasingly more obvious, and the vast majority of experts agree on the fact that these are largely caused by human activity. Several international programmes were implemented lately to mitigate climate-related environmental global challenges. Nevertheless, the results expected by the institutions are still out of range in many cases. At the same time, societies have seen a significant proliferation of “Communities-Based Initiatives” (Cbi), based on individual voluntary participation to take action for a sustainable transition. Some scholars argue that such bottom-up activities can give better results in terms of sustainability than top-down policies. However, a theoretical-methodological framework for a quantitatively robust estimate of the contribution that Cbi may bring in alleviating human pressure on the environment has never been performed. This work’s objectives are threefold: offering a critical review of the main limitations inherent to the Environmental Impact Assessment of Cbi’s activities; developing a simple and sufficiently exhaustive theoretical- methodological framework to assess the environmental performance of Cbi s allowing for inter and intra domains comparison; discussing some preliminary results regarding peculiar and representative case-studies, belonging to a Cbis’ portfolio collected by the FP7 EU project Towards European Societal Sustainability (FP7 Tess - Grant Agreement n ° 603705). francaisMesurer l’impact environnemental des initiatives communautaires : une reflexion preliminaire sur la disponibilite des donnees et les limitations methodologiques. – Les consequences du changement climatique mondial sont de plus en plus evidentes, et la grande majorite des experts sont d’accord sur le fait qu’elles sont en grande partie causees par l’activite humaine. Plusieurs programmes internationaux ont ete mis en oeuvre dans les dernieres decennies pour l’attenuation des changements climatiques. Neanmoins, les resultats attendus par les institutions sont encore hors de portee. Dans le meme temps, la societe a constate une proliferation importante d’initiatives des Communautes (Cbi), basees sur la participation volontaire individuelle au fin de promouvoir une transition durable. Certains chercheurs soutiennent que quelques activites bottom-up peuvent donner des meilleurs resultats en termes de durabilite que les politiques top-down. Toutefois, un cadre theorique et methodologique pour une evaluation quantitativement robuste de la contribution apportee par les Cbi dans la reduction de la pression humaine sur l’environnement n’a jamais ete developpe. Les objectifs de ce travail sont trois: developper une lecture critique concernant les limites principales inherentes a l’evaluation de l’impact environnemental des Cbi; developper un cadre theorique et methodologique simple et suffisamment exhaustive pour l’evaluation; discuter des resultats preliminaires concernant des cas d’etudes particuliers, analyses au cours des travaux du projet europeen de la recherche Tess (Towards European Societal Sustainability) (FP7 Tess - accord de subvention n ° 603705).

The use of models to study the dynamics of transitions is challenging because of several aspects of transitions, notably complexity, multi-domain and multi-level interactions. These challenges are shared by other research areas that extensively make use of mod-els. In this article we survey experiences and methodological approaches developed in the research areas of social-ecological modeling, integrated assessment, and environmental modeling, and derive lessons to be learnt for model use in transition studies. In order to account for specific challenges associated with different kinds of model applications we classify models according to their uses: for understanding transitions, for providing case-specific policy advice, and for facilitating stakeholder processes. The assessment reveals promising research directions for transition modeling, such as model-to-model analysis, pattern-oriented modeling, advanced sensitivity analysis, development of a shared conceptual framework, and use of modeling protocols.

We have assembled CO2 emission figures from collections of urban GHG emission estimates published in peer-reviewed journals or reports from research institutes and non-governmental organizations. Analyzing the scaling with population size, we find that the exponent is development dependent with a transition from super- to sub-linear scaling. From the climate change mitigation point of view, the results suggest that urbanization is desirable in developed countries. Further, we compare this analysis with a second scaling relation, namely the fundamental allometry between city population and area, and propose that density might be a decisive quantity too. Last, we derive the theoretical country-wide urban emissions by integration and obtain a dependence on the size of the largest city.

Global environmental-change is evident, and undeniably it is mostly induced by anthropogenic activities.Several programs fuelling climate-change mitigation were lately implemented; all fostering specific and ambitious targets.Although some improvements were regionally observed, regrettably the expected results are in many cases still out of reach.Contemporaneously, societies experienced a proliferation of grass-roots initiatives calling for individual participation in fostering societal sustainable transition.Scholars advocate that bottom-up activities may outperform top-down policies in reaching sustainability; however, a methodological framework to intelligibly assess CBIs' impact on socio-ecological systems is still unexplored.This paper aims at: illustrating main caveats in assessing CBIs' environmental impacts, proposing a general methodological framework, presenting results from a pan-European research

Diagnostic analyses of hydrological models intend to improve the understanding of how processes and their dynamics are represented in models. Temporal patterns of parameter dominance could be precisely characterized with a temporally resolved parameter sensitivity analysis. In this way, the discharge conditions are characterized, that lead to a parameter dominance in the model. To achieve this, the analysis of temporal dynamics in parameter sensitivity is enhanced by including additional information in a three-tiered framework on different aggregation levels. Firstly, temporal dynamics of parameter sensitivity provide daily time series of their sensitivities to detect variations in the dominance of model parameters. Secondly, the daily sensitivities are related to the flow duration curve (FDC) to emphasize high sensitivities of model parameters in relation to specific discharge magnitudes. Thirdly, parameter sensitivities are monthly averaged separately for five segments of the FDC to detect typical patterns of parameter dominances for different discharge magnitudes. The three methodical steps are applied on two contrasting catchments (upland and lowland catchment) to demonstrate how the temporal patterns of parameter dynamics represent different hydrological regimes. The discharge dynamic in the lowland catchment is controlled by groundwater parameters for all discharge magnitudes. In contrast, different processes are relevant in the upland catchment, because the dominances of parameters from fast and slow runoff components in the upland catchment are changing over the year for the different discharge magnitudes. The joined interpretation of these three diagnostic steps provides deeper insights of how model parameters represent hydrological dynamics in models for different discharge magnitudes. Thus, this diagnostic framework leads to a better characterization of model parameters and their temporal dynamics and helps to understand the process behaviour in hydrological models. Copyright (c) 2015 John Wiley & Sons, Ltd.

Human development has far-reaching impacts on the surface of the globe. The transformation of natural land cover occurs in different forms, and urban growth is one of the most eminent transformative processes. We analyze global land cover data and extract cities as defined by maximally connected urban clusters. The analysis of the city size distribution for all cities on the globe confirms Zipf’s law. Moreover, by investigating the percolation properties of the clustering of urban areas we assess the closeness to criticality for various countries. At the critical thresholds, the urban land cover of the countries undergoes a transition from separated clusters to a gigantic component on the country scale. We study the Zipf-exponents as a function of the closeness to percolation and find a systematic dependence, which could be the reason for deviating exponents reported in the literature. Moreover, we investigate the average size of the clusters as a function of the proximity to percolation and find country specific behavior. By relating the standard deviation and the average of cluster sizes—analogous to Taylor’s law—we suggest an alternative way to identify the percolation transition. We calculate spatial correlations of the urban land cover and find long-range correlations. Finally, by relating the areas of cities with population figures we address the global aspect of the allometry of cities, finding an exponent δ ≈ 0.85, i.e., large cities have lower densities.

[This corrects the article DOI: 10.1371/journal.pone.0062228.].

Changing food consumption patterns and their environmental impacts have been a matter of the scientific debate over decades. Agriculture is a major greenhouse gas (GHG) emitter and thus, holds a large potential for climate change mitigation. Population growth and diet changes are two main drivers of global food demand. We investigate diet changes globally on a country basis, estimate diet embodied emissions, and project future agricultural emissions. Additionally, we estimate future livestock feed demand due to changing dietary habits towards meat rich diets. Lastly, we explore the potential of regions shifting to local food considering both the present state and the future scenarios including climate change and diet shifts. Globally, we identified sixteen dietary patterns between 1961 and 2007 with food intake ranging from 1870 to 3400 kcal/cap/day. Dietary patterns are changing towards more meat rich diets worldwide. Due to a large share of animal products, very high calorie diets exhibit large per capita emissions of 3.7-6.1 kg CO2eq./day. Globally, 1.9 billion people can be fed by local food produced within their 5’ grid while about 1 billion Asian and African require intercontinental trade. By closing crop yield gaps, Asia and Africa can be food self-sufficient. This also reduces international trade and increases a self-sufficient population in a 5’ grid up to 2.9 billion. However, such a degree of food self-sufficiency can only be achieved by when farmers grow diverse crops increasing agro-diversity and consumers rely more on local products. By 2050, agricultural emissions will approach 7 Gt CO2 eq./yr and global feed demand will remain similar to 2000 due to population growth. This will change tremendously when diet changes are also accounted e.g. emissions of 20 Gt CO2eq./yr and 1.3 times increase in feed demand. Furthermore, the number of people depending on international trade will vary between 1.5 and 6 billion. The effects of diet shifts and closing yield gaps will be stronger on international trade. Moreover, agricultural trade will increase by 4% to 16% due to climate change. Closing yield gaps is a viable option to meet the future food demand in addition to enhancing agro-diversity, shifting diets towards lower share of animal products, and relying more on local food.

We examine the suitability of using the multi-level perspective to describe disaster-related transitions and their barriers in an institutional environment that expects disaster responders, such as government agencies, to adhere to the increasingly established principles of disaster risk reduction. We created a process-tracing test based on disaster and transition literature and applied it to two cases: Cyclone Nargis and Hurricane Katrina. In applying this test we found that multi-level perspective is a valid way to describe disaster-related transitions. We also determined that both the concepts of build back better and disaster risk reduction influenced the transitions. Moreover, a lack of resources and a strong government desire for control presented obstacles to transition. These disaster-related transitions have implications for policy considerations. Knowledge from this article can inform future studies on disaster response and recovery.

To ensure reliable results of hydrological models, it is essential that the models reproduce the hydrological process dynamics adequately. Information about simulated process dynamics is provided by looking at the temporal sensitivities of the corresponding model parameters. For this, the temporal dynamics of parameter sensitivity are analysed to identify the simulated hydrological processes. Based on these analyses it can be verified if the simulated hydrological processes match the observed processes of the real world. We present a framework that makes use of processes observed in a study catchment to verify simulated hydrological processes. Temporal dynamics of parameter sensitivity of a hydrological model are interpreted to simulated hydrological processes and compared with observed hydrological processes of the study catchment. The results of the analysis show the appropriate simulation of all relevant hydrological processes in relation to processes observed in the catchment. Thus, we conclude that temporal dynamics of parameter sensitivity are helpful for verifying simulated processes of hydrological models.

Global food production needs to be increased by 60-110% between 2005 and 2050 to meet growing food and feed demand. Intensification and/or expansion of agriculture are the two main options available to meet the growing crop demands. Land conversion to expand cultivated land increases GHG emissions and impacts biodiversity and ecosystem services. Closing yield gaps to attain potential yields may be a viable option to increase the global crop production. Traditional methods of agricultural intensification often have negative externalities. Therefore, there is a need to explore location-specific methods of sustainable agricultural intensification. We identified regions where the achievement of potential crop calorie production on currently cultivated land will meet the present and future food demand based on scenario analyses considering population growth and changes in dietary habits. By closing yield gaps in the current irrigated and rain-fed cultivated land, about 24% and 80% more crop calories can respectively be produced compared to 2000. Most countries will reach food self-sufficiency or improve their current food self-sufficiency levels if potential crop production levels are achieved. As a novel approach, we defined specific input and agricultural management strategies required to achieve the potential production by overcoming biophysical and socioeconomic constraints causing yield gaps. The management strategies include: fertilizers, pesticides, advanced soil management, land improvement, management strategies coping with weather induced yield variability, and improving market accessibility. Finally, we estimated the required fertilizers (N, P2O5, and K2O) to attain the potential yields. Globally, N-fertilizer application needs to increase by 45-73%, P2O5-fertilizer by 22-46%, and K2O-fertilizer by 2-3 times compared to the year 2010 to attain potential crop production. The sustainability of such agricultural intensification largely depends on the way management strategies for closing yield gaps are chosen and implemented.