Ensuring a well-rounded diet that includes essential nutrients and minerals is crucial during a child's formative years. It not only impacts their physical well-being but also plays a significant role in their mental development. Research indicates that children facing hunger or illnesses in their early years can experience enduring physiological repercussions (Martins et al, 2011) contributing to academic struggles, increased dropout rates, and limited employment opportunities (Young, 1996). Despite substantial global efforts, there is still a concerning number of children under the age of five who are too thin for their height (referred to as ‘wasting’). In 2022, approximately 45 million children globally fell into this category, with over half of them residing in South Asia (Joint Malnutrition Estimates, 2022). Wasting can occur due to a complex interplay involving poverty, disease, caregiving practices, and dietary patterns, all of which vary depending on the context (Harding et al, 2018). All these factors prevent children from attaining sufficient nutrition in their early years which not only jeopardize their individual potential but also extends to far-reaching effects on labor productivity, impeding economic advancement, and potentially perpetuating intergenerational effects.
There is growing evidence that variability in temperature and precipitation affect consumption of micronutrients. It changes the yields of important crop sources of micronutrients, alters the nutritional content of a specific crop, and influences decisions to grow crops of different nutritional value (Burke and Lobell, 2009). This exacerbates the heightened susceptibility of children to wasting, especially in low-income and lower-middle income countries where it is already a growing concern. Furthermore, children also suffer from a range of diseases such as respiratory diseases, malaria, diarrhea caused by air pollution, high temperature and frequent rainfalls that have direct implications on nutritional intakes (Bunyavanich et al, 2003). While food availability and accessibility are widely studied in the climate literature, the impact of climate change on proper utilization of food remains understudied (Burke and Lobell, 2009). Therefore, in this paper, we focus on children's nutrition in the face of the inevitable challenges posed by climate change.
We study the effects of temperature and precipitation shocks on the weight-to-height z scores of children in the three distinct agro-ecological regions of Nepal: Mountains, Hills, and Terai (lowlands). All regions have varying climates due to altitudes ranging from 700 meters in the Terai region to 8,848 meters in the Mountain region. Since most of the literature in this area are focused in Sub-Saharan Africa (Antilla-Hughes et al, 2021; Thiede and Gray, 2020) where temperatures are extreme, we utilize the unique features of Nepal with varied climatic conditions, to look at whether the effects persist in rising yet moderate weather extremes across the regions. This also assists us in determining the effectiveness of nationwide programs in countries with different topographies, and see whether it is important to tailor to suit specific environments. Furthermore, we attempt to understand the mechanisms through which weather variability affects nutrition.
We carry out this research by combining the Policy and Science for Health, Agriculture and Nutrition (PoSHAN) annual surveys of households with children less than 5 years old, collected across the three regions in Nepal from 2013–2016, with the average temperature and precipitation data at district level. We exploit the exogenous shock – weather variation in wards across years to form causality between fluctuations in weather and its impact on children’s nutrition using fixed effects. Since the relation between temperature and the outcomes is non-linear (Schlenker and Roberts, 2009); Lobes et al, 2011); Zhao et al, 2017), we utilize a widely adopted measure in agriculture called Growing Degree Days (GDD) to better understand the mechanisms affecting children’s nutritional intake. Growing Degree Days (GDD) is the sum of truncated degrees on a given day between two boundaries suitable for the crops to grow, and Harmful Degree Days (HDD) measure the days when the temperature exceeds the optimum level.
Unlike existing literature, we find that rising temperature does not have a negative impact rather a positive effect on the weight-to-height z score in the Terai region. The results in the other regions remain insignificant. A 1°C increase in average temperature shifts the weight-to-height z-score by 0.15 standard deviation from the mean in the Terai region. This is consistent with temperature anomalies which are deviations from the long-term average from 1979–2016. The positive relation may exist because contrary to existing literature, the average temperature used in this paper does not surpass the conventional extreme temperatures found in the other studied regions. On the other hand, average precipitation and long-term average precipitation does not have any significant effect in any of the regions. There is no significant difference in the outcome for male and female children. The Multi-sectoral Nutrition Program (MSNP) that was rolled out nationwide in 2013, did significantly decrease the effect of temperature on weight-to-height z score.
Since the relationship between average temperature and weight-to-height z score is non-linear, we use another measure, Growing Degree Days, to study this impact. We find that there is a positive relation between Growing Degree Days and weight-to-height z score, and a negative relation between Harmful Degree Days and weight-to-height z score in the Terai region. This supports our hypothesis that agriculture is an influential pathway through which weather affects weight-to-height z score. We find that a 100-units increase in Growing Degree Days shifts weight-to-height z score by 0.22. Likewise, a 10-unit increase in Harmful Degree Days creates a negative shift in weight-to-height z score by 0.27 standard deviation. Therefore, even though extreme temperatures above 35 degree Celsius is not common, if the trend of rising temperature continues, there are high chances that children in the Terai region will become malnourished.
Most of the literature in the growing field of climate change and children’s nutrition are targeted in warmer African countries and typhoon-prone coastal countries. Antilla-Hughes et al (2021) find that warmer El Niño conditions predict worse child undernutrition in the developing countries, but better outcomes in areas where precipitation is positively affected by warmer ENSO (El Niño Southern Oscillation). Randell, Gray and Grace (2020) show that higher temperatures in utero and more rainfall during the third trimester are positively associated with severe stunting in Ethiopia. Likewise, Thiede and Gray (2020) show that delay in monsoon onset during the prenatal period is associated with reduced child height among children aged 2-4 years in Indonesia. We contribute to the existing literature by focusing on a landlocked country with varying yet moderate climatic conditions. We also add to the literature on nonlinear temperature effects (Schlenker and Roberts, 2009; Lobes et al, 2011; Zhao et al, 2017) by studying its relation with children’s weight-to-height z score.