The findings indicate that targeted efforts to prevent child undernutrition may be needed during ENSO events.
The El Niño Southern Oscillation (ENSO) is a key component of the climate system that influences weather conditions around the world. It is well known that ENSO has impacts on agricultural output, especially in countries in the tropics. However, the degree to which these changes impact human health is not well understood or quantified.
Jesse Anttila-Hughes, Amir Jina, and Gordon McCord combine observations of ENSO variations with data from demographic and health surveys that cover 1.3 million children from 51 countries between 1986 and 2018. They find that in most of the countries in the sample, an El Niño event is associated with a below average weight-for-age score in children in the same year. This is seen mainly in countries in which El Niño causes a precipitation deficit, while the opposite pattern emerges in a smaller set of countries that see an increase in precipitation during El Niño events. The authors indicate that the weight of children recovers, but a reduction in the height of affected children can be seen years later. Over the course of the time period studied, the authors observed that there was no significant change in this relationship, indicating that improved economic conditions in many countries have not reduced the impact of ENSO.
The authors conclude that ENSO may be considered as a predictor of child undernutrition in many countries in the tropics and that targeted action is needed to reduce its impact on children's health.