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Agricultural adaptation to climate change is critical for ensuring future food security. Social capital is important for climate change adaptation, but institutions and social networks at multiple scales (e.g., household, community, and institution) have been overlooked in studying agricultural climate change adaptation. We combine data from 13 sites in 11 low-income countries in East Africa, West Africa, and South Asia to explore how multiple scales of social capital relate to household food security outcomes among smallholder farmers. Using social network theory, we define three community organizational social network types (fragmented defined by lack of coordination, brokered defined as having a strong central actor, or shared defined by high coordination) and examine household social capital through group memberships. We find community and household social capital are positively related, with higher household group membership more likely in brokered and shared networks. Household group membership is associated with more than a 10% reduction in average months of food insecurity, an effect moderated by community social network type. In communities with fragmented and shared organizational networks, additional household group memberships is associated with consistent decreases in food insecurity, in some cases up to two months; whereas in brokered networks, reductions in food insecurity are only associated with membership in credit groups. These effects are confirmed by hierarchical random effects models, which control for demographic factors. This suggests that multiple scales of social capital—both within and outside the household—are correlated with household food security. This social capital may both be bridging (across groups) and bonding (within groups) with different implications for how social capital structure affects food security. Efforts to improve food security could recognize the potential for both household and community level social networks and collaboration, which further research can capture by analyzing multiple scales of social capital data.

Abstract. An improved understanding of present-day climate variability and change relies on high-quality data sets from the past 2 millennia. Global efforts to model regional climate modes are in the process of being validated against, and integrated with, records of past vegetation change. For South America, however, the full potential of vegetation records for evaluating and improving climate models has hitherto not been sufficiently acknowledged due to an absence of information on the spatial and temporal coverage of study sites. This paper therefore serves as a guide to high-quality pollen records that capture environmental variability during the last 2 millennia. We identify 60 vegetation (pollen) records from across South America which satisfy geochronological requirements set out for climate modelling, and we discuss their sensitivity to the spatial signature of climate modes throughout the continent. Diverse patterns of vegetation response to climate change are observed, with more similar patterns of change in the lowlands and varying intensity and direction of responses in the highlands. Pollen records display local-scale responses to climate modes; thus, it is necessary to understand how vegetation–climate interactions might diverge under variable settings. We provide a qualitative translation from pollen metrics to climate variables. Additionally, pollen is an excellent indicator of human impact through time. We discuss evidence for human land use in pollen records and provide an overview considered useful for archaeological hypothesis testing and important in distinguishing natural from anthropogenically driven vegetation change. We stress the need for the palynological community to be more familiar with climate variability patterns to correctly attribute the potential causes of observed vegetation dynamics. This manuscript forms part of the wider LOng-Term multi-proxy climate REconstructions and Dynamics in South America – 2k initiative that provides the ideal framework for the integration of the various palaeoclimatic subdisciplines and palaeo-science, thereby jump-starting and fostering multidisciplinary research into environmental change on centennial and millennial timescales.

SUMMARYThis article discusses how decentralisation policies are enacted in the planning and implementation of natural resource management interventions in rural Ethiopia. A key element of decentralisation policy is the emphasis on greater participation by local communities. Drawing on qualitative research conducted with government staff and farmers, this paper illustrates how different actors perceive and implement national policy and how these actions affect the longer‐term sustainability of land management interventions. Copyright © 2014 John Wiley & Sons, Ltd.

espanolSe presentan los resultados de un estudio sobre la significancia y la optimizacion de algunas variables (granulometria, velocidad de aire, contenido de biomasa y disposicion del reactor) en el poder calorifico del gas de sintesis obtenido de la gasificacion de biomasa (carbon vegetal y cuesco de palma africana). Mediante un diseno de experimento se evaluaron las cuatro variables que oscilaban entre 8-13mm para la granulometria, 0.8-1.4m/s para la velocidad del aire, 0-100 para el contenido de biomasa y ascendente-descendente para la disposicion del reactor. Se encontro que los factores correspondientes a la granulometria y el contenido de biomasa resultan ser los mas significativos en el poder calorifico del gas. Un poder calorifico maximo de 3.84MJ/Nm3 se obtuvo con la disposicion descendente del reactor, alimentacion de carbon vegetal con granulometria de 13mm y suministro maximo de flujo de aire. La verificacion del punto optimo de operacion mostro que tales condiciones de operacion favorecian la produccion de un gas con un alto poder calorifico. EnglishThe results of study on the significance and the optimization of some variables (particle size, air flow, biomass content and reactor disposition) in the calorific value of the synthesis gas obtained by gasification process of biomass (vegetal coal and biomass African palm) is presented. The four variables ranged from 8-13mm for the particle size, 0.8-1.4m/s for air flow, 0-100 for biomass content and updraft-downdraft disposition for the type of reactor were evaluated by an experimental design. It was found that the particle size and biomass content are the most significant factors to maximize the output calorific value of syngas. A maximum calorific value of 3.84MJ/Nm3 was obtained using the downdraft reactor with 13mm particle size and maximum air flow supply. The verification of the optimum operating point under these conditions showed that such operating conditions favored the production of a gas with high calorific value.

This work is the result to the study a different systems of exhaust pipes. The manufacturers of motorbike use a system with several volumes to reduce noise and use a catalyst to reduce emissions. In contrast, the manufacturers of exhaust system decided made a system using a perforated pipe and a rock wool to noise reducing. This system changes the pressure drop and temperature of exhaust gases and, therefore, request a different composition of catalyst.In this communication, it is shown the tests released in a test bench according with the cycle WLTC and the limits are the defined for EURO3. Where, we have changed the type of catalyst, the diameter of the end pipe and the calibration of electronic control unit of engine in order to measure following the test of homologation.The results of the different experiments indicate is very important the pressure drop in the replace exhaust system must be similar to the original system. The composition of the catalyst and the operating temperature are critical to reduce the emissions and the calibration of engine is the main influence. Keywords: Exhaust systems, Catalyst, Regulatory emissions, WLTC

Extreme events usually cause numerous economic and social losses, especially in vulnerable countries, such as Brazil. Understanding whether the evolution of Earth System Models (ESMs) from Coupled Model Intercomparison Project (CMIP) improves the representation of extreme events and investigating their future change is fundamental because device policies of adaptation and mitigation to climate change generally consider the results of the most recent generation of ESMs. This study analyzes the performance of a subset of 40 ESMs from CMIP3, CMIP5, and CMIP6 in simulating eight extreme precipitation climate indices over Brazil during 1981–2000 and also estimates their projected changes for the middle (2046–2065) and far future (2081–2 100) under the worst-case scenario for each CMIP generation. Results reveal that CDD are the most challenging precipitation index to be simulated, while the best ones were PRCPTOT and R20mm. The model performance shows that CMIP3 has the best skill for Northeast Brazil, CMIP5 for Center-West, and CMIP6 for North, Southeast and South regions. Thus, at least for Brazil, the evolution of the ESMs from CMIP did not reflect a substantial improvement in the representation of precipitation climate extremes over all Brazilian regions. In addition, all the models across CMIP generations have difficulty in simulating the observed trends. This indicate that improvements are still needed in CMIP models. Despite the relative low performance in the historical climate, the climate projections indicate a consensus signal among most of precipitation climate extremes and CMIP generations, which increase its reliability. Overall, the extreme precipitation events are projected to be more severe, frequent, and long-lasting in all Brazilian regions, with the more pronounce changes expected in heavy rainfall and severe droughts in the central northern portion of Brazil and in the southern sector.

Climate disasters affect human security and development, moreso in fragile and conflict-affected contexts where population’ capacities to cope with climate change are compromised. Responses to such crises lie at the nexus of humanitarian assistance, development, and peacebuilding. Yet, there are still too few integrated programmatic responses coordinating peacebuilding and climate actions to ensure a progressive human development. This research develops a multi-scalar model to help actors identify thematic areas to inform synergistic efforts and programs at different scales to better coordinate their actions. Findings suggest that climate action and peacebuilding sectors can coordinate actions around climate and conflict risk assessments, the management of land and water resources, ecosystem restoration, nature-based climate adaptation, climate and conflict smart agriculture, natural resources governance, and sustainable market development. These collaborative efforts have the potential to generate co-benefits, such as increased social cohesion and livelihood creation.