Temperature anomalies undermine the health of reproductive-age women in low- and middle-income countries.

Climate change is expected to undermine population health and well-being in low- and middle-income countries, but relatively few analyses have directly examined these effects using individual-level data at global scales, particularly for reproductive-age women. To address this lacuna, we harmonize nationally representative data from the Demographic and Health Surveys on reproductive health, body mass index (BMI), and temporary migration from 2.5 million adult women (ages 15 to 49) in approximately 109,000 sites across 59 low- and middle-income countries, which we link to high-resolution climate data. We use this linked dataset to estimate fixed-effect logistic regression models of demographic and health outcomes as a function of climate exposures, woman-level and site-level characteristics, seasonality, and regional time trends, allowing us to plausibly isolate climate effects from other influences on health and migration. Specifically, we measure the effects of recent exposures to temperature and precipitation anomalies on the likelihood of having a live birth in the past year, desire for another child, use of modern contraception, underweight (BMI < 18.5), and temporary migration, and subsequently allow for nonlinearity as well as heterogeneity across education, rural/urban residence, and baseline climate. This analysis reveals that exposures to high temperatures increase live births, reduce desire for another child, increase underweight, and increase temporary migration, particularly in rural areas. The findings represent clear evidence that anthropogenic temperature increases contribute to temporary migration and are a significant threat to women's health and reproductive autonomy in low- and middle-income countries.

The Gendered Consequences of COVID-19 for Internal Migration.

Scant evidence exists to identify the effects of the pandemic on migrant women and the unique barriers on employment they endure. We merge longitudinal data from mobile phone surveys with subnational data on COVID cases to examine whether women were left more immobile and vulnerable to health risks, relative to men, during the pandemic in Kenya and Nigeria. Each survey interviewed approximately 2000 men and women over three rounds (November 2020-January 2021, March-April 2021, November 2021-January 2022). Linear regression analysis reveals internal migrants are no more vulnerable to knowing someone in their network with COVID. Rather, rural migrant women in Kenya and Nigeria were less vulnerable to transmission through their network, perhaps related to the possible wealth accumulation from migration or acquired knowledge of averting health risks from previous destinations. Per capita exposure to COVID cases hinders the inter-regional migration of women in both countries. Exposure to an additional COVID case per 10,000 people resulted in a decline in women's interregional migration by 6 and 2 percentage points in Kenya and Nigeria, respectively.

"Measuring the Environmental Context of Child Growth in Burkina Faso".

Child growth failure, as indicated by low height-for-age z-scores (HAZ), is an important metric of health, social inequality, and food insecurity. Understanding the environmental pathways to this outcome can provide insight into how to prevent it. While other studies have examined the environmental determinants of HAZ, there is no agreed upon best-practices approach to measure the environmental context of this outcome. From this literature, we derive a large set of potential environmental predictors and specifications including temperature and precipitation levels, anomalies, and counts as well as vegetation anomalies and trends, which we include using linear, nonlinear, and interactive specifications. We compare these measures and specifications using four rounds of DHS survey data from Burkina Faso and a large set of fixed effects regression models, focusing on exposures from the time of conception through the second year of life and relying on joint hypothesis tests and goodness-of-fit measures to determine which approach best explains HAZ. Our analysis reveals that nonlinear and interactive transformations of climate anomalies, as opposed to climate levels or vegetation indices, provide the best explanation of child growth failure. These results underline the complex and nonlinear pathways through which climate change affects child health and should motivate climate-health researchers to more broadly adopt measures and specifications that capture these pathways.

The Childhood Origins of Climate-Induced Mobility and Immobility.

The literature on climate exposures and human migration has focused largely on assessing short-term responses to temperature and precipitation shocks. In this paper, we suggest that this common coping strategies model can be extended to account for mechanisms that link environmental conditions to migration behavior over longer periods of time. We argue that early-life climate exposures may affect the likelihood of migration from childhood through early adulthood by influencing parental migration, community migration networks, human capital development, and decisions about household resource allocation, all of which are correlates of geographic mobility. After developing this conceptual framework, we evaluate the corresponding hypotheses using a big data approach, analyzing 20 million individual georeferenced records from 81 censuses implemented across 31 countries in tropical Africa, Latin America, and Southeast Asia. For each world region, we estimate regression models that predict lifetime migration (a change in residence between birth and ages 30-39) as a function of temperature and precipitation anomalies in early life, defined as the year prior to birth through age four. Results suggest that early-life climate is systematically associated with changes in the probability of lifetime migration in most regions of the tropics, with the largest effects observed in sub-Saharan Africa. In East and Southern Africa, the effects of temperature shocks vary by sex and educational attainment and in a manner that suggests women and those of lower socioeconomic status are most vulnerable. Finally, we compare our main results with models using alternative measures of climate exposures. This comparison suggests climate exposures during the prenatal period and first few years of life are particularly (but not exclusively) salient for lifetime migration, which is most consistent with the hypothesized human capital mechanism.

Climate Change and Household Debt in Rural India.

Climate change and indebtedness have been repeatedly highlighted as major causes of distress for rural households in India. However, despite the close connection between climate conditions and rural livelihoods, there has been little attempt to systematically examine the association between the two. To address this gap, we combine national-level longitudinal data from IHDS, MERRA-2, and the Indian Ministry of Agriculture to study the impact of climate anomalies on household indebtedness across rural India. Using a longitudinal approach that accounts for potential confounders at household, village, and district levels, we find pervasive effects of season-specific, five-year climate anomalies on multiple dimensions of household debt, particularly in arid and semi-arid areas. Most notably, temperature anomalies in the winter cropping season in arid and semi-arid areas are associated with increasing household indebtedness. We further find that climate change interacts with existing socioeconomic differences-caste and landholding in particular-to deepen both the size and the depth of indebtedness for rural households.

Climatic conditions and household food security: Evidence from Tanzania.

Food security and adequate nutrition are critical for achieving progress toward sustainable development. Two billion people worldwide experience moderate to severe food insecurity, and rates of hunger have increased over the past several years after declining steadily for decades. The FAO attributes this increase in large part to climate change, though empirical evidence on the relationship between climatic conditions and food security remains limited. We examine this question by linking nationally representative longitudinal data from four rounds of the Tanzania National Panel Survey to high-resolution gridded climate data. We then estimate a set of fixed effects regression models to understand the linkages between recent rainy season precipitation and temperature and two indicators of household food security: Food Consumption Score (FCS) and reduced Coping Strategies Index (rCSI). We find that low rainfall-particularly dry and cool conditions-is negatively associated with food security. Moving from a typical rainfall year to a particularly dry one increases the risk of being food insecure on both measures simultaneously by 13-percentage points. This suggests that a lack of rainfall impedes households' ability to access food, likely through reduced agricultural production and increased food prices, leading to lower dietary diversity and food shortages. Vulnerability is higher among households with fewer working age members, suggesting that households with a greater supply of labor can better withstand droughts. As climate change alters precipitation and temperature patterns over the coming decades, policies to increase resilience will be critical for improving food security, particularly among populations heavily reliant on agriculture.

Climate change, social vulnerability and child nutrition in South Asia.

Despite recent advancements in global population well-being and food security, climate change threatens to undermine child nutritional health, particularly for marginalized populations in tropical low- and middle-income countries. South Asia is at particular risk for climate-driven undernutrition due to a combination of historical weather exposures, existing nutritional deficits, and a lack of sanitation access. Previous studies have established that precipitation extremes increase rates of undernutrition in this region, but the existing literature lacks adequate consideration of temperature anomalies, mediating social factors, and the developmentally-relevant timing of exposure. We combine high-resolution temperature and precipitation data with large-sample survey data on household demographics and child anthropometry, using an approach that incorporates three key developmental periods and a rigorous fixed effects design. We find that precipitation extremes in the first year of life significantly decrease children's height-for-age (HAZ) in South Asia. The detrimental effects of extreme precipitation are especially concentrated in under-resourced households, such as those lacking access to proper sanitation and education for women, while anomalous heat is particularly harmful for children in Pakistan, though it tends to benefit children in some demographic groups. These results indicate that nutritional status in South Asia is highly responsive to climate exposures, and that addressing sanitation infrastructure and other development priorities is a pathway towards reducing this vulnerability.

Climate anomalies and childhood growth in Peru.

Climate change has been linked to poor childhood growth and development through maternal stress, nutritional insults related to lean harvests, and exposure to infectious diseases. Vulnerable populations are often most susceptible to these stressors. This study tested whether susceptibility to linear growth faltering is higher among Peruvian children from indigenous, rural, low-education, and low-income households. High-resolution weather and household survey data from Demographic and Health Survey 1996-2012 were used to explore height-for-age z-scores (HAZ) at each year of life from 0 to 5. Rural, indigenous children at age 0-1 experience a HAZ reduction of 0.35 units associated with prenatal excess rainfall which is also observed at age 4-5. Urban, non-indigenous children at age 4-5 experience a HAZ increase of 0.07 units associated with postnatal excess rainfall, but this advantage is not seen among rural, indigenous children. These findings highlight the need to consider developmental stage and social predictors as key components in public health interventions targeting increased climate change resilience.

Climate-Induced Migration and Unemployment in Middle-Income Africa.

One of the major unresolved questions in the study of vulnerability to climate change is how human migration will respond in low and middle-income countries. The present study directly addresses this lacuna by using census data on migration from 4 million individuals from three middle-income African countries over a 22-year period. We link these individuals to climate exposures in their origins and estimate climatic effects on migration using a fixed-effects regression model. We show that climate anomalies affect mobility in all three countries. Specifically, mobility declines by 19% with a 1-standard deviation increase in temperature in Botswana. Equivalent changes in precipitation cause declines in migration in Botswana (11%) and Kenya (10%), and increases in migration in Zambia (24%). The mechanisms underlying these effects appear to differ by country. Negative associations between precipitation anomalies, unemployment, and inactivity suggest migration declines may be due to an increased local demand for workers to offset production risk, while migration increases may be indicative of new opportunities in destinations. These country-specific findings highlight the contextually-specific nature of climate-migration relationships, and do not support claims that climate change is widely contributing to urbanization across Africa.

Climate exposures and child undernutrition: Evidence from Indonesia.

Global climate change has the potential to disrupt agricultural systems, undermine household socioeconomic status, and shape the prevalence and distribution of diseases. Each of these changes may influence children's nutritional status, which is sensitive to food availability, access, and utilization, and which may have lasting consequences for later-life health and socioeconomic outcomes. This paper contributes to the emerging literature on climate and child health by studying the effects of temperature and precipitation exposures on children's height and weight in Indonesia. Drawing on five rounds of the Indonesian Family Life Survey (IFLS) implemented between 1993 and 2015, we estimate fixed-effects regression models of height-for-age (HFA) and weight-for-height (WFH) among samples of children ages 24-59 months and 0-23 months, respectively. We test for heterogeneity in these effects across sub-populations expected to vary in their vulnerability. Results show that delays in monsoon onset are consistently associated with worse child health outcomes. Delays in monsoon onset during the prenatal period are associated with reduced child height among children age 2-4 years. The weight of young (<2 years) children is adversely affected by delays in the most recent monsoon season, and this relationship is particularly strong among residents of Java. Overall, our results underline the need for interventions that protect children's nutrition and underlying health against the effects of climate change.

Stunted from the start: Early life weather conditions and child undernutrition in Ethiopia.

This paper examines the relationship between weather conditions and child nutrition in Ethiopia. We link data from four rounds of the Ethiopia Demographic and Health Survey to high-resolution climate data to measure exposure to rainfall and temperature in utero and during early life. We then estimate a set of multivariate regression models to understand how weather conditions impact child stunting, an indicator of sustained early life undernutrition. We find that greater rainfall during the rainy seasons in early life is associated with greater height for age. In addition, higher temperatures in utero, particularly during the first and third trimesters, and more rainfall during the third trimester, are positively associated with severe stunting, though stunting decreases with temperature in early life. We find potential evidence for a number of pathways underlying the weather-child nutrition relationship including agricultural livelihoods, heat stress, infectious disease transmission, and women's time use during pregnancy. These findings illuminate the complex pathways through which climate change may influence child health and should motivate additional research focused on identifying the causal mechanisms underlying these links.

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.

The changing climate-migration relationship in China, 1989-2011.

A persistent concern about the social consequences of climate change is that large, vulnerable populations will be involuntarily displaced. Existing evidence suggests that changes in precipitation and temperature can increase migration in particular contexts, but the potential for this relationship to evolve over time alongside processes of adaptation and development has not been widely explored. To address this issue, we link longitudinal data from 20 thousand Chinese adults from 1989-2011 to external data on climate anomalies, and use this linked dataset to explore how climatic effects on internal migration have changed over time while controlling for potential spatial and temporal confounders. We find that temperature anomalies initially displaced permanent migrants at the beginning of our study period, but that this effect had reversed by the end of the study period. A parallel analysis of income shares suggests that the explanation might lie in climate vulnerability shifting from agricultural to non-agricultural livelihood activities. Taken together with evidence from previous case studies, our results open the door to a potential future in which development and in-situ adaptation allow climate-induced migration to decline over time, even as climate change unfolds.

Spatial and Temporal Dimensions of Weather Shocks and Migration in Nepal.

Research shows that environmental shocks can influence migration. However, studies vary widely in the shocks and type of migration measured, the context, and the strength and direction of environmental effects. In addition, existing theories provide opposing predictions for this relationship. There is a clear need for further theoretical development in the climate-migration literature. This study, in rural Nepal, examines four types of weather shocks, over various time frames, on four types of migration. Results suggest that the most substantial influence of weather shocks is not in a wholesale increase or decrease in migration. Instead, weather shocks are related to changes in the type of migration used, resulting in less long-term and more short-term migrations in the population. We use the Ready-Willing-and-Able perspective to make sense of these patterns.

Temporary Migration and Climate Variation in Eastern Africa.

Africa is likely to experience warming and increased climate variability by the late 21st century. Climate extremes have been linked to adverse economic outcomes. Hence, adaptation is a key component of the United Nations Framework Convention on Climate Change agreements and development assistance. Effective climate adaptation policy requires an understanding of how temperature and rainfall variability affect migration patterns. Yet, how individuals in developing countries manage climate variation is poorly understood, especially in Africa. Combining high-resolution climate data with panel micro-data on migration, labor participation, and demographics, we employ regression analysis to assess temporary migration responses to local temperature and precipitation anomalies in four East African countries. We find that climate impacts are most pronounced in urban areas, with a standard deviation temperature increase and rainfall decrease leading to respective 10 and 12 percent declines in out-migration relative to mean values. Evidence from other labor market outcomes suggests that urban out-migration is not associated with reduced local employment opportunities. Instead, declines in urban out-migration appear to coincide with negative local climate employment impacts. These results challenge the narrative that temporary out-migration serves as a safety valve during climate extremes and that climate change will most strongly affect out-migration rates from rural areas in developing countries.

Characterizing the Indigenous Forest Peoples of Latin America: Results from Census Data.

Indigenous populations in Latin America are central to regional and global efforts toward achieving socially and environmentally sustainable development. However, existing demographic research on indigenous forest peoples (IFPs) has many limitations, including a lack of comparable cross-national evidence. We address this gap by linking representative census microdata to satellite-derived tree cover estimates for nine countries in the region. Our analyses describe the demographic and socioeconomic characteristics of IFPs, and draw comparisons with reference groups. Our first goal is to examine within- and between-population variation in the age structure, human capital attainment, and economic status of IFPs. We then analyze patterns of fertility among indigenous forest-dwelling women and comparison groups. Finally, we examine the association between migration patterns and tree cover among indigenous and non-indigenous populations. Findings demonstrate that Latin America's IFPs are materially deprived and characterized by high fertility levels overall. Importantly for sustainable development efforts, we show that non-indigenous forest-dwellers outnumber IFPs by more than eight to one and that IFPs have lower fertility than their non-indigenous counterparts when other characteristics are accounted for. Additionally, we find that most in-migrants to heavily-forested areas are non-indigenous, and that in-migrants tend to settle in areas that are forested but have few indigenous inhabitants. These results provide new cross-national evidence on the state of IFPs in Latin America, and highlight the need to empower these groups in the face of growing social and environmental crises in the region.

Do Social Protection Programs Foster Short-term and Long-term Migration Adaptation Strategies?

We examine how migration is influenced by temperature and precipitation variability, and the extent to which the receipt of a cash transfer affects the use of migration as an adaptation strategy. Climate data is merged with georeferenced panel data (2010-2014) on individual migration collected from the Zambian Child Grant Program (CGP) sites. We use the person-year dataset to identify the direct and heterogeneous causal effects of the CGP on mobility. Having access to cash transfers doubles the rate of male, short-distance moves during cool periods irrespective of wealth. Receipt of cash transfers (among wealthier households) during extreme heat causes an additional retention of males. Cash transfers positively spur long-distance migration under normal climate conditions in the long term. They also facilitate short-distance responses to climate, but not long-distance responses that might be demanded by future climate change.

Climate anomalies, land degradation and rural out-migration in Uganda.

Globally, rural livelihoods are increasingly challenged by the dual threats of land degradation and climate change. These issues are of particular concern in sub-Saharan Africa, where land degradation is believed to be severe and where climate change will bring higher temperatures and shifts in rainfall. To date, however, we know little about the relative effects of these various potential environmental stressors on migration. To examine these processes, we link longitudinal data from 850 Ugandan households with environmental data on soils, forests, and climate, and then analyze these data using approaches that account for potential spatial and temporal confounders. Our findings reveal that climate anomalies, rather than land degradation, are the primary contributor to environmental migration in Uganda, with heat stress of particular importance. Short hot spells increase temporary migration, an element of a diversified household livelihood strategy, while long-term heat stress induces permanent migration through an agricultural livelihoods pathway.

Smallholder responses to climate anomalies in rural Uganda.

Recent research suggests that sub-Saharan Africa will be among the regions most affected by the negative social and biophysical ramifications of climate change. Smallholders are anticipated to respond to rising temperatures and precipitation anomalies through on-farm management strategies and diversification into off-farm activities. Few studies have empirically examined the relationship between climate anomalies and rural livelihoods. Our research explores the impact of climate anomalies on farmers' on and off-farm livelihood strategies, considering both annual and decadal climate exposures, the relationship between on and off-farm livelihoods, and the implications of these livelihood strategies for agricultural productivity. To examine these issues, we link gridded climate data to survey data collected in 120 communities from 850 Ugandan households and 2,000 agricultural plots in 2003 and 2013. We find that smallholder livelihoods are responsive to climate exposure over both short and long time scales. Droughts decrease agricultural productivity in the short term and reduce individual livelihood diversification in the long term. Smallholders cope with higher temperatures in the short term, but in the long run, farmers struggle to adapt to above-average temperatures, which lower agricultural productivity and reduce opportunities for diversification. On and off-farm livelihood strategies also appear to operate in parallel, rather than by substituting for one another. These observations suggest that in order to sustain rural livelihoods, new strategies will be necessary if smallholders are to successfully adapt to climate change.

Climate Shocks Constrain Human Fertility in Indonesia.

Climate change is likely to induce a large range of household- and individual-level responses, including changes in human fertility behaviors and outcomes. These responses may have important implications for human and economic development and women's empowerment. Drawing on the literature linking climate conditions to rice cultivation in Indonesia, we use longitudinal household survey and high-resolution climate data to explore changes in childbearing intentions, family planning use, and births following community-level climate shocks from 1993 to 2015. We find that fertility intentions increase and family planning use declines in response to delays in monsoon onset occurring within the previous year, particularly for wealthier populations. However, women on farms are significantly more likely to use family planning and less likely to give birth following abnormally high temperatures during the previous five years. We also measure parallel shifts in household well-being as measured by rice, food, and non-food consumption expenditures. Our findings advance the environmental fertility literature by showing that longer duration environmental shocks can have impacts on fertility behaviors and outcomes. Collectively, our results illustrate human fertility responses to climate change in a country vulnerable to its effects, and demonstrate that in some cases, climate shocks can constrain human fertility.