Lifestyle

Examining the effects of extreme precipitations on the physical and cognitive development of children

El Niño-Southern Oscillation (ENSO) and rainfall shocks are often cited as the most important risk factor faced by households in rural, less developed and rain-fed agricultural settings. Now, research by University of Massachusetts Amherst economist Marta Vicarelli finds that such weather shocks experienced during the early stages of life have significant effects on the cognitive, anthropometric and behavioral indicators of children measured between 2-6 years of age.

In a new paper published online by the journal World Development, Vicarelli and co-author Arturo Aguilar of Instituto Tecnológico Autónomo de México (ITAM) examine the effects that extreme precipitations experienced during the early stages of life have had on the physical and cognitive development of children in poor rural areas of Mexico.

By examining the effects of ENSO-related extreme precipitation shocks that caused floods and impacted the 1998-99 maize harvest seasons, and using geographical variation in precipitation, Vicarelli and Aguilar compared children exposed to the weather shock in early stages of life versus same-aged children not exposed to extreme precipitations. The researchers found that, on average, children affected between their in-utero development and 2 years of age exhibit 0.06 standard deviations (SDs) lower weight, 0.05 SDs lower height and a higher likelihood of stunting (8.3 percentage points). They also found that language development, working memory and visual-spatial thinking test scores of these children are, 0.19, 0.17 and 0.15 SDs lower than same-aged children not exposed, respectively. The effects are particularly pronounced for children who were 1-2 years old when the shock occurred.

These impacts are equivalent to a three- to four-month delay in development, the researchers note, which could later be exacerbated if not addressed. They note that short- and long-term memory and visual-spatial capabilities during childhood have been proven to be strong predictors of academic and professional achievements later in life, and that stimuli or stressful conditions during critical periods in early life can have permanent consequences into adulthood. They say that the evidence provided in their new paper will help better understand how the early shocks translate to effects that remain into adulthood.

“Vulnerability to climate extremes is worsening with climate change and it is exacerbated in El Niño and La Niña years,” says Vicarelli, assistant professor of economics and public policy at UMass Amherst. “The results of our study provide insights on possible socio-economic impacts of climate change in developing countries, particularly in terms of human capital formation. We hope that our results will contribute to the discussion on climate adaptation and disaster risk reduction.”

Changes in household food consumption and diet composition induced by the weather shock appear to be key drivers behind the impacts on children’s cognitive and physical development. Total household income reported two months after the weather extreme event occurred was 32% lower for households living in the exposed regions. This negative income effect from the weather shock persisted at least one year after the event.

Diet composition presented significant changes, as well. The year after the extreme event, households in affected regions reported a 28% contraction in their consumption of animal-origin proteins and a 10% decrease in their consumption of fruits and vegetables. The researchers note that overall food intake measured in total amount of kilograms and calories was not affected, which suggests that households oriented their food selection toward less nutritious and cheaper items following the event. They believe that this poor nutrition may have negatively affected the children’s cognitive and physical development.

Meanwhile, the area of Mexico that the researchers examined was targeted by one of the most extensively studied anti-poverty governmental programs—PROGRESA—at the time of the shock. This allowed Vicarelli and Aguilar to examine whether PROGRESA’s cash transfers allowed households to mitigate their vulnerability to ENSO-related weather extremes. They say that their findings of only partial evidence of mitigation from the delivery of PROGRESA and other government programs suggests that, if not addressed promptly and with targeted policies, the cognitive functioning delays induced by climate extremes may not be easily recovered. The timing, targeting and amount of support received could be crucial aspects to at least partially protect cognitive and physical development outcomes for young children after climate-change related weather shocks, they argue.

“As climate change adaptation and disaster risk management have become mainstream in development work, there has been growing international attention to strategies minimizing exposure of vulnerable populations to climate-related extreme events,” Vicarelli says. “Uninsured losses may keep vulnerable populations in poverty or trigger poverty traps.”

The authors note that post-COVID-19 recovery plans currently under development in numerous countries focus on climate resilience, climate mitigation and economic expansion to aid future debt repayment.

“Our results suggest that in developing countries at high climate risk, climate resilience strategies aimed at reducing vulnerability to weather extremes could benefit children’s physical and cognitive development,” Vicarelli says. “And this would consequently bring long-term socio-economic benefits for society at large.”