Climate variability and child nutrition: Findings from sub-Saharan Africa

Highlights

• Climate variability may influence nutrition through multiple pathways.

• High temperatures and low precipitation reduce child weight.

• High temperatures also increase the risk of wasting.

• Climate effects are generally consistent across sub-populations.

Abstract

Climatic variability affects many underlying determinants of child malnutrition, including food availability, access, and utilization. Evidence of the effects of changing temperatures and precipitation on children’s nutritional status nonetheless remains limited. Research addressing this knowledge gap is merited given the short- and long-run consequences of malnutrition. We address this issue by estimating the effects of temperature and precipitation anomalies on the weight and wasting status of children ages 0–59 months across 18 countries in sub-Saharan Africa. Linear regression models show that high temperatures and low precipitation are associated with reductions in child weight, and that high temperatures also lead to increased risk of wasting. We find little evidence of substantively meaningful differences in these effects across sub-populations of interest. Our results underscore the vulnerability of young children to climatic variability and its second-order economic and epidemiological effects. The study also highlights the corresponding need to design and assess interventions to effectively mitigate these impacts.

Introduction

Changing temperature and precipitation patterns associated with climate change are expected to disrupt food systems across the world through impacts on agricultural production, as well as on the health and socioeconomic status of agricultural laborers and consumers (Bosello et al., 2006, Dell et al., 2012, McMichael et al., 2006, Myers et al., 2014, Nelson et al., 2014). Such impacts have clear implications for food security, as they will affect the availability of food and households’ ability to access and fully utilize food for adequate nutrition (Barrett, 2010, Wheeler and Von Braun, 2013). One relatively understudied implication is that climatic variability and its second-order effects are likely to affect levels and patterns of malnutrition (Phalkey et al., 2015). These impacts are anticipated to be concentrated among children, who are especially vulnerable to food and nutritional insecurity. Malnutrition may increase children’s risk of other morbidities and mortality (Pelletier et al., 1995), and malnutrition during early childhood can permanently diminish individuals’ health and socioeconomic attainment over the life course (Alderman et al., 2006, Currie and Vogl, 2013, Maccini and Yang, 2009, Van den Berg et al., 2009). Unmitigated exposure to climate variability among children may have residual health and social costs decades into the future.

We contribute to the emerging climate-nutrition literature by analyzing the respective effects of temperature and precipitation anomalies on child weight-for-height (WHZ) and wasting (WHZ < -2) across a sample from 18 countries in sub-Saharan Africa. Using data from the Demographic and Health Surveys (DHS), combined with historical climate records from the University of East Anglia’s Climate Research Unit Time Series (Boyle et al., 2018, Harris et al., 2014), we estimate a series of multivariate regression models to address two overarching objectives. First, we estimate the association between recent exposure to climatic variability and children’s weight, measured both continuously and as a binary indicator of low weight (i.e., wasting). Second, we test for systematic variation in these effects across socioeconomic groups that we expect to be differentially vulnerable to changing environmental conditions. We focus this second set of analyses on wasting since the health and social costs of such acute malnutrition are high. Our analyses reveal that exposure to high temperatures is associated with reductions in WHZ and corresponding increases in the prevalence of wasting. The overall direction of temperature effects on wasting are remarkably similar across multiple sub-populations of interest, with only modest differences between rural and urban populations. Precipitation deficits are associated with reduced WHZ, but these changes do not translate into increased wasting risk. Together, our findings underline the need to develop evidence-based interventions to protect children from the health effects of environmental change.