Social cohesion and passive adaptation in relation to climate change and disease

Climate change affects biophysical processes related to the transmission of many infectious diseases, with potentially adverse consequences for the health of communities. While our knowledge of biophysical associations between meteorological factors and disease is steadily improving, our understanding of the social processes that shape adaptation to environmental perturbations lags behind. Using computational modeling methods, we explore the ways in which social cohesion can affect adaptation of disease prevention strategies when communities are exposed to different environmental scenarios that influence transmission pathways for diseases such as diarrhea. We developed an agent-based model in which household agents can choose between two behavioral strategies that offer different levels of protection against environmentally mediated disease transmission. One behavioral strategy is initially set as more protective, leading households to adopt it widely, but its efficacy is sensitive to variable weather conditions and stressors such as floods or droughts that modify the disease transmission system. The efficacy of the second strategy is initially moderate relative to the first and is insensitive to environmental changes. We examined how social cohesion (defined as average number of household social network connections) influences health outcomes when households attempt to identify an optimal strategy by copying the behaviors of socially connected neighbors who seem to have adapted successfully in the past. Our simulation experiments suggest that high-cohesion communities are able to rapidly disseminate the initially optimal behavioral strategy compared to low-cohesion communities. This rapid and pervasive change, however, decreases behavioral diversity; i.e., once a high cohesion community settles on a strategy, most or all households adopt that behavior. Following environmental changes that reduce the efficacy of the initially optimal strategy, rendering it suboptimal relative to the alternative strategy, high-cohesion communities can fail to adapt. As a result, despite faring better early in the course of computational experiments, high-cohesion communities may ultimately experience worse outcomes. In the face of uncertainty in predicting future environmental stressors due to climate change, strategies to improve effective adaptation to optimal disease prevention strategies should balance between intervention efforts that promote protective behaviors based on current scientific understanding and the need to guard against the crystallization of inflexible norms. Developing generalizable models allows us to integrate a wide range of theories and multiple datasets pertaining to the relationship between social mechanisms and adaptation, which can provide further understanding of future climate change impacts. Models such as the one we present can generate hypotheses about the mechanisms that underlie the dynamics of adaptation events and suggest specific points of measurement to assess the impact of these mechanisms. They can be incorporated as modules within predictive simulations for specific socio-ecological contexts.     

Measuring household vulnerability to climate change—Why markets matter

Climate change and climate variability affect households in developing countries both directly through their impact on crop yields and indirectly through their impact on wages, food prices and the livelihoods of the poor. Therefore, vulnerable household groups cannot be identified without considering their position in and access to markets. I illustrate the effects – transmitted through markets – that are significant in household exposure, sensitivity and adaptive capacity to climate change by simulating productivity shocks to maize up to 2030 due to climate change in a computable general equilibrium model of Malawi. The results show that rural households with large land holdings may benefit from the adverse impact of climate change on maize yields as a result of increased maize prices. Urban poor and small-scale farmers are vulnerable to climate change due to the large portion of their incomes spent on food. Existing vulnerability measures that do not consider equilibrium effects and characterise all farmers as vulnerable may therefore be misleading.     

山区孕灾环境下地震和极端天气气候对地质灾害的影响

开展多致灾因子耦合作用下的地质灾害研究对山区综合风险防范和可持续发展至关重要。在山区孕灾环境中,极端降水和地震是触发滑坡等地质灾害的主要因素。以往研究多在山地孕灾环境稳定的假设下,研究极端降水或强震单独导致的地质灾害过程,而对孕灾环境变化下的极端天气和地震致灾因子共同诱发地质灾害的关注不足。针对这一问题,梳理了国内外发生在山区的地震和极端降水共同导致滑坡等地质灾害的研究案例,系统总结了山区强震与极端降水引发滑坡等地质灾害的相互作用过程。现有研究已在地震和极端降水引发滑坡等地质灾害的问题上取得了以下认识：(1)山区地震可强烈改变孕灾环境,显著提升震后降水引发地质灾害的可能性,放大极端降水-滑坡灾害链;(2)地震对降水引发滑坡的影响随着震后时间的推移逐渐减弱,该现象可能受控于气候因素;(3)在全球气候变化背景下,极端天气气候事件增多,定量研究山区强震和极端天气气候二者“遭遇”下的地质灾害链将面临更多挑战。由于观测案例不足,针对山区地震与极端降水共同导致地质灾害的研究仍缺少定量分析,触发机理也需进一步明确。     

East African food security as influenced by future climate change and land use change at local to regional scales

Climate change impacts food production systems, particularly in locations with large, vulnerable populations. Elevated greenhouse gases (GHG), as well as land cover/land use change (LCLUC), can influence regional climate dynamics. Biophysical factors such as topography, soil type, and seasonal rainfall can strongly affect crop yields. We used a regional climate model derived from the Regional Atmospheric Modeling System (RAMS) to compare the effects of projected future GHG and future LCLUC on spatial variability of crop yields in East Africa. Crop yields were estimated with a process-based simulation model. The results suggest that: (1) GHG-influenced and LCLUC-influenced yield changes are highly heterogeneous across this region; (2) LCLUC effects are significant drivers of yield change; and (3) high spatial variability in yield is indicated for several key agricultural sub-regions of East Africa. Food production risk when considered at the household scale is largely dependent on the occurrence of extremes, so mean yield in some cases may be an incomplete predictor of risk. The broad range of projected crop yields reflects enormous variability in key parameters that underlie regional food security; hence, donor institutions’ strategies and investments might benefit from considering the spatial distribution around mean impacts for a given region. Ultimately, global assessments of food security risk would benefit from including regional and local assessments of climate impacts on food production. This may be less of a consideration in other regions. This study supports the concept that LCLUC is a first-order factor in assessing food production risk.     

Yield Variability as Influenced by Climate: A Statistical Investigation

One of the issues with respect to climate change involves its influence on the distribution of future crop yields. Many studies have been done regarding the effect on the mean of such distributions but few have addressed the effect on variance. Furthermore, those that have been done generally report the variance from crop simulators, not from observations. This paper examines the potential effects of climate change on crop yield variance in the context of current observed yields and then extrapolates to the effects under projected climate change. In particular, maximum likelihood panel data estimates of the impacts of climate on year-to-year yield variability are constructed for the major U.S. agricultural crops. The panel data technique used embodies a variance estimate developed along the lines of the stochastic production function approach suggested by Just and Pope. The estimation results indicate that changes in climate modify crop yield levels and variances in a crop-specific fashion. For sorghum, rainfall and temperature increases are found to increase yield level and variability. On the other hand, precipitation and temperature are individually found to have opposite effects on corn yield levels and variability.     

A bridge too far? The influence of socio-cultural values on the adaptation responses of smallholders to a devastating pest outbreak in cocoa

The influence of socio-cultural factors on the adaptive capacity, resilience and trade-offs in decision-making of households and communities is receiving growing scholarly attention. In many partly transformed societies, where the market economy is not well developed, livelihood practices are heavily structured by kinship and indigenous social and economic values. Farm investment decisions and incentives to produce agricultural commodities are shaped by a host of considerations in addition to market imperatives like profit. In one such partly transformed society in East New Britain Province, Papua New Guinea, we examine the adaptation decisions of smallholders in response to the drastic drop of yield in their cocoa plots caused by the sudden outbreak of Cocoa Pod Borer. To explain why the impact of the pest has been so great we examine the interconnections between household responses, the local socio-cultural and economic context of smallholder commodity crop production and the wider institutional environment in which household choices and decisions are made. We argue that the significant lifestyle changes and labour intensive farming methods required for the effective control of Cocoa Pod Borer are incompatible with existing smallholder farming systems, values and livelihoods. To adopt a high input cropping system requires more than a technical fix and some training; it also requires abandoning a ‘way of life’ that provides status, identity and a moral order, and which is therefore highly resistant to change. The paper highlights the enduring influence and significance of local, culturally-specific beliefs and socio-economic values and their influence on how individuals and communities make adaptation decisions.     

基于气象要素的逐日玉米产量气象影响指数

利用1981—2020年5—9月气象数据与玉米产量数据,通过改进逐日降水适宜度并构建逐日气候适宜度模型,建立基于相似年逐日气象要素的作物生育期气候适宜度序列,利用气象产量与气候适宜指数建立模型,设计逐日作物产量气象影响指数以表征气象条件对作物的影响程度,基于该指数构建东北地区玉米逐日产量预报模型并分析其逐日预报准确率,用以表明该指数的准确性。结果表明:利用3个相似年预报结果加权集成综合相似年逐日作物产量气象影响指数可提高逐日预报准确率,黑龙江年尺度逐日预报准确率年际间波动小于东北其他地区。综合相似年月尺度下,随着玉米发育期的推进和实时气象数据的引入,月尺度平均预报准确率逐渐提高。东北地区玉米产量8月31日的日尺度预报准确率普遍高于7月31日;辽宁日尺度预报差异较大,但随着玉米发育期推进逐日预报产量和实际产量接近,准确率也提高。基于气象要素构建的逐日作物产量影响指数和同期气象影响指数可以定量评估不同时段气象条件对作物产量的影响程度,在一定程度上可提高农业气象业务定量化评价水平。     

Resettlement and climate change vulnerability: Evidence from rural China

The literature on migration and climate change has become increasingly attuned to the role of climatic factors in already complex migration dynamics, and amid different kinds of mobility. However, to date little evidence has been provided of the relationship between resettlement and climate change, including the degree to which resettlement may shape the vulnerability of households or communities. In this article we ask: is there any evidence that resettlement may be a driver of vulnerability and if so, what factors make resettled households more vulnerable when compared to non-resettled households? These questions are considered with reference to new evidence drawn from a livelihoods-based vulnerability analysis in a drought-prone, poverty county in China’s Shanxi Province, which encompassed households involved in local poverty resettlement programs. Evidence of the characteristics of resettled households compared to non-resettled households shows that resettlement adversely impacts on the household asset base, particularly in terms of financial and natural capital. It may therefore be a driver of vulnerability. At a time when the Chinese government is repackaging resettlement as a climate change adaptation measure, this article provides evidence that resettlement as it is currently practiced has the potential to amplify rather than alleviate household vulnerability to climate change.     

The effect of changes in daily and interannual climatic variability on CERES-Wheat: A sensitivity study

We investigate the effect of changes in daily and interannual variability of temperature and precipitation on yields simulated by the CERES-Wheat model at two locations in the central Great Plains. Changes in variability were effected by adjusting parameters of the Richardson daily weather generator. Two types of changes in precipitation were created: one with both intensity and frequency changed; and another with change only in persistence. In both types mean total monthly precipitation is held constant. Changes in daily (and interannual) variability of temperature result in substantial changes in the mean and variability of simulated wheat yields. With a doubling of temperature variability, large reductions in mean yield and increases in variability of yield result primarily from crop failures due to winter kill at both locations. Reduced temperature variability has little effect. Changes in daily precipitation variability also resulted in substantial changes in mean and variability of yield. Interesting interactions of the precipitation variability changes with the contrasting base climates are found at the two locations. At one site where soil moisture is not limiting, mean yield decreased and variability of yield increased with increasing precipitation variability, whereas mean yields increased at the other location, where soil moisture is limiting. Yield changes were similar for the two different types of precipitation variability change investigated. Compared to an earlier study for the same locations wherein variability changes were effected by altering observed time series, and the focus was on interannual variability, the present results for yield changes are much more substantial. This study demonstrates the importance of taking into account change in daily (and interannual) variability of climate when analyzing the effect of climate change on crop yields.The National Center for Atmospheric Research is sponsored by the National Science Foundation.     

Policy support,social capital,and farmers’ adaptation to drought in China

Increasingly severe drought has not only threatened food security but also resulted in massive socio-economic losses. In the face of increasingly serious drought conditions, the question of how to mitigate its impacts through appropriate measures has received great attention. The overall goal of this study is to examine the influence of policies and social capital on farmers’ decisions to adopt adaptation measures against drought. The study is based on a large-scale household and village survey conducted in six provinces nationwide. The survey results show that 86% of rural households have taken adaptive measures to protect crop production against drought, most of which are non-engineering measures. In the case of non-engineering measures, changing agricultural production inputs and adjusting seeding or harvesting dates are two popular options. A multivariate regression analysis reveals that government policy support against drought such as releasing early warning information and post-disaster services, technical assistance, financial and physical supports have significantly improved farmers’ ability to adapt to drought. However, since only 5% of villages benefited from such supports, the government in China still has significant room to implement these assistances. Moreover, having a higher level of social capital in a farm household significantly increases their adaptation capacity against drought. Therefore, the government should pay particular attention to the farming communities, and farmers within a community who have a low level of social capital. Finally, farmers’ ability to adapt to drought is also associated with the characteristics of their households and local communities. The results of this study also have implications for national adaptation plans for agriculture under climate change in other developing countries.     

Impacts of land use intensification on human wellbeing: Evidence from rural Mozambique

Intensifying land use is often seen as a corollary of improving rural livelihoods in developing countries. However, land use intensification (LUI) frequently has unintended impacts on ecosystem services (ES), which may undermine the livelihoods of the same people who could benefit from intensification. Poorer households are disproportionately dependent on ES, so inequalities may also rise. A disaggregated analysis of LUI is thus fundamental to better understand how LUI can progress in an equitable manner. Using a suite of multi-scale, multidisciplinary social-ecological methods and operationalising multidimensional concepts of land use intensity and wellbeing, we examine three case studies in rural Mozambique. Drawing on interviews, focus group discussions, 1576 household surveys and geospatial data from 27 Mozambican villages, we assess how wellbeing and inequality change with three common LUI pathways: transitions to smallholder commercial crop production, charcoal production, and subsistence expansion. Wellbeing improved with intensification of smallholder commercial and subsistence agriculture, inequality did not change. Unsustainable intensification of charcoal production showed no overall effect on either wellbeing or inequality. Improvements in wellbeing amongst the poorest households were only found with intensification of commercial crop production, where villages had better access to markets. Our findings suggest that socioeconomic benefits from agricultural intensification and expansion may overcome localised environmental trade-offs, at least in the short term. However, unsustainable charcoal resource management and limited productive investment opportunities for rural households resulted in both reduced market access and limited wellbeing improvements. Sustainable and inclusive markets are therefore crucial developments alongside LUI to sustain wellbeing improvements for all households, to ensure that no one is left behind.     

Quantifying sources of uncertainty in projected wheat yield changes under climate change in eastern Australia

Future climate projections and impact analyses are pivotal to evaluate the potential change in crop yield under climate change. Impact assessment of climate change is also essential to prepare and implement adaptation measures for farmers and policymakers. However, there are uncertainties associated with climate change impact assessment when combining crop models and climate models under different emission scenarios. This study quantifies the various sources of uncertainty associated with future climate change effects on wheat productivity at six representative sites covering dry and wet environments in Australia based on 12 soil types and 12 nitrogen application rates using one crop model driven by 28 global climate models (GCMs) under two representative concentration pathways (RCPs) at near future period 2021–2060 and far future period 2061–2100. We used the analysis of variance (ANOVA) to quantify the sources of uncertainty in wheat yield change. Our results indicated that GCM uncertainty largely dominated over RCPs, nitrogen rates, and soils for the projections of wheat yield at drier locations. However, at wetter sites, the largest share of uncertainty was nitrogen, followed by GCMs, soils, and RCPs. In addition, the soil types at two northern sites in the study area had greater effects on yield change uncertainty probably due to the interaction effect of seasonal rainfall and soil water storage capacity. We concluded that the relative contributions of different uncertainty sources are dependent on climatic location. Understanding the share of uncertainty in climate impact assessment is important for model choice and will provide a basis for producing more reliable impact assessment.     

Using panel data to estimate the effect of rainfall shocks on smallholders food security and vulnerability in rural Ethiopia

Ethiopia??s agriculture is predominantly rainfed and hence any irregularity in weather conditions has adverse welfare implications. Using panel data, this paper analyzes the effect of rainfall shocks on Ethiopian rural households?? food security and vulnerability over time while controlling for a range of other factors. To this end, we generate a time-variant household food security index which is developed by principal components analysis. Based on this index, households are classified into relative food security groups and their socioeconomic differences are assessed. The exploratory results show that compared to the less secured households, the more secured ones have male and literate household heads, tend to have a greater number of economically active household members, own more livestock, experience better rainfall outcome, and participate in local savings groups. Using the food security index as the dependent variable, we use a fixed effects instrumental variable regression model to identify determinants of households?? food security over time and find that rainfall variability is an important factor. Moreover, household size, participation in local savings groups, and livestock ownership positively affect food security. Results from multinomial logistic regression model complement the fixed effects instrumental variable regression results by showing that the level and variability of rainfall are important determinants of persistent food insecurity and vulnerability. The results highlight the need for efficient risk reduction and mitigation programs to improve risk exposure and coping ability of rural households. Careful promotion of investment in infrastructure to support irrigation and water resources development is one aspect worth considering.     

Social capital,trust, and adaptation to climate change: Evidence from rural Ethiopia

Climate change is expected to have particularly severe effects on poor agrarian populations. Rural households in developing countries adapt to the risks and impacts of climate change both individually and collectively. Empirical research has shown that access to capital—financial, human, physical, and social—is critical for building resilience and fostering adaptation to environmental stresses. Little attention, however, has been paid to how social capital generally might facilitate adaptation through trust and cooperation, particularly among rural households and communities. This paper addresses the question of how social capital affects adaptation to climate change by rural households by focusing on the relationship of household and collective adaptation behaviors. A mixed-methods approach allows us to better account for the complexity of social institutions—at the household, community, and government levels—which drive climate adaptation outcomes. We use data from interviews, household surveys, and field experiments conducted in 20 communities with 400 households in the Rift Valley of Ethiopia. Our results suggest that qualitative measures of trust predict contributions to public goods, a result that is consistent with the theorized role of social capital in collective action. Yet qualitative trust is negatively related to private household-level adaptation behaviors, which raises the possibility that social capital may, paradoxically, be detrimental to private adaptation. Policymakers should account for the potential difference in public and private adaptation behaviors in relation to trust and social capital when designing interventions for climate adaptation.     

Deciphering interwoven drivers of environment-related migration – A multisite case study from the Ethiopian highlands

Global environmental change is increasing livelihood pressure for many communities, and agricultural households in the Global South are particularly vulnerable. Extant research has debated whether and to what degree this amplifies migration flows while also acknowledging that migration can be an adaptive strategy. However, little is known about which contextual factors are most relevant and how they interact in shaping environment-related migration. We shed light on this issue by conducting an in-depth qualitative, yet multisite and medium-N study of farming households in the northern Ethiopian highlands. We utilized qualitative comparative analysis (QCA) – a novel approach in the research field – to overcome the existing methodological challenges. We found that the migration experience within the household in combination with either the usage of the longer summer rainy season (Kiremt) or non-farm in situ diversification are sufficient causes for migration. Non-farm income activities and favorable environmental conditions during the Kiremt season increases economic household resources and as such migration ability. However, only together with migrant networks, which can reduce the costs and risks of migration and shape migration aspirations, can these drivers explain why households engage in migration. Our findings reveal that capabilities and networks, rather than commonly cited push factors, are far more important drivers of environment-related migration at the household level. Additionally, we illustrate that while migration is an important adaptation strategy, it cannot be adopted equally among households and as a result often reinforces existing inequalities.     

Is resilience socially constructed? Empirical evidence from Fiji,Ghana, Sri Lanka,and Vietnam

The objective of this paper is to better understand the various individual and household factors that influence resilience, that is, people⬢s ability to respond adequately to shocks and stressors. One of our hypotheses is that resilience does not simply reflect the expected effects of quantifiable factors such as level of assets, or even less quantifiable social processes such as people⬢s experience, but is also determined by more subjective dimensions related to people⬢s perceptions of their ability to cope, adapt or transform in the face of adverse events. Data collected over two years in Fiji, Ghana, Sri Lanka and Vietnam confirms the importance of wealth in the recovery process of households affected by shocks and stressors. However our results challenge the idea that within communities, assets are a systematic differentiator in people⬢s response to adverse events. The findings regarding social capital are mixed and call for more research: social capital had a strong positive influence on resilience at the community level, yet our analysis failed to demonstrate any tangible positive correlation at the household level. Finally, the data confirm that, like vulnerability, resilience is at least in part socially constructed, endogenous to individual and groups, and hence contingent on knowledge, attitudes to risk, culture and subjectivity.     

The household production function approach to valuing climate: the case of Japan

According to household production function theory households combine marketed goods and nonmarket environmental goods to produce service flows of direct value to the household. This readily explains why, as an input to household production activities, households might have preferences over the climate. Using techniques more frequently employed to account for differences in the demographic composition of households we use household production function theory to estimate climate equivalence scales using household expenditure data drawn from 51 Japanese cities over the period 2000–2009. Our results indicate that warmer temperatures result in a small but statistically highly significant reduction in the cost of living. Combining these estimates with climate change scenarios associated with the IPCC A2, A1B, and B1 emissions scenarios other things being equal points to a slight reduction in Japanese households’ cost of living.     

Stability and change within indigenous land use in the Ecuadorian Amazon

In the Amazon basin and other tropical forest regions, many forested landscapes are inhabited by indigenous peoples who are increasingly exposed to infrastructure expansion, large-scale natural resource extraction, and development programs. How indigenous land use evolves in this context will be a critical determinant of the future of these forests. To date, few studies have had access to longitudinal, large-sample and field-based data that enables the measurement of indigenous land use change and its correlates in these contexts. To address this lacuna, we make use of a unique multi-ethnic household survey conducted in 32 indigenous communities of the Northern Ecuadorian Amazon in 2001 and again with the same households in 2012. We analyze these data to measure land use and land use change as well as their determinants. This reveals that the overall household agropastoral footprint has remained close to constant over time, but with important changes within particular land uses and ethnicities. Notably, cacao has largely replaced coffee (tracking commodity price changes), and Kichwa and Shuar households have intensified production on increasingly subdivided plots, with the Shuar specializing in cattle. In contrast, Waorani and Cofán households have maintained small footprints, while Secoya households largely abandoned cattle ranching. Taken together, the results emphasize ethnic heterogeneity in indigenous land use change, a pattern which is only visible through the use of a longitudinal, large-sample, field-based design.     

Rural household demographics, livelihoods and the environment

This paper reviews and synthesizes findings from scholarly work on linkages among rural household demographics, livelihoods and the environment. Using the livelihood approach as an organizing framework, we examine evidence on the multiple pathways linking environmental variables and the following demographic variables: fertility, migration, morbidity and mortality, and lifecycles. Although the review draws on studies from the entire developing world, we find the majority of microlevel studies have been conducted in either marginal (mountainous or arid) or frontier environments, especially Amazonia. Though the linkages are mediated by many complex and often context-specific factors, there is strong evidence that dependence on natural resources intensifies when households lose human and social capital through adult morbidity and mortality, and qualified evidence for the influence of environmental factors on household decision-making regarding fertility and migration. Two decades of research on lifecycles and land cover change at the farm level have yielded a number of insights about how households make use of different land-use and natural resource management strategies at different stages. A thread running throughout the review is the importance of managing risk through livelihood diversification, ensuring future income security, and culture-specific norms regarding appropriate and desirable activities and demographic responses. Recommendations for future research are provided.     

Studying climate-related yield fluctuations of basic grain crops and their qualitative assessment under new socioeconomic conditions of the Russian Federation

Regularities of variability of grain crop yield by grain planting regions of the Russian Federation related to farming standards and a change in climatic conditions in the Soviet (1960–1990) and post-Soviet (1991–2008) periods are studied. The revealed regularities of the climate-related variability of the grain crop yield will be used in the process of adaptation of the weather-yield model to the present levels of the yield.