Two surveys released this month warn of the effects of climate extremes on children. One of them is a survey commissioned by the Maria Cecilia Souto Vidigal Foundation from Datafolha: more than 80% of Brazilians fear the effects of climate change on babies and children aged 0 to 6 years.
The study Early Childhood Overview: the impact of the climate crisis interviewed 2,206 people, 822 of whom were responsible for children, between April 8 and 10, 2025. The biggest fears focus on impacts on health: 7 out of 10 people (71%) expressed this type of concern, with emphasis on respiratory diseases.
Other issues raised by 39% of respondents were the greater risk of disasters (such as floods, droughts and fires), in addition to the difficulty in accessing clean water and food (32% of responses).
According to the study, 15% believe that climate change will cause greater environmental awareness and 6% trust that society will find solutions to reduce damage.
“Seeing that the population recognizes the risk that children face is already a victory — it means that we understand who is on the front line of the crisis and that there is an urgency to act. Children in early childhood are the least to blame for the climate emergency and yet they are the most affected public. This injustice requires that every measure taken considers the vulnerability of those who depend on the protection of adults,” said Mariana Luz, director of the Maria Cecilia Souto Vidigal Foundation.
Infant mortality
The other study corroborates the population’s concern. It was conducted by scientists from the Center for Data and Knowledge Integration for Health (Cidacs/Fiocruz Bahia), the Institute of Public Health (ISC) at the Federal University of Bahia (UFBA), the London School and the Barcelona Institute for Global Health.
Published in the journal Environmental Research, the research indicates that babies in the neonatal period (7 to 27 days) are the most affected by the cold, with a 364% greater risk of dying in extreme conditions, compared to normal conditions. Regarding heat, the impact increases as the child ages, being 85% greater in extreme heat among those aged between 1 and 4 years.
Researchers analyzed more than 1 million under-5 deaths over 20 years. The risk of mortality in this age group was 95% higher in extreme cold and 29% higher in extreme heat than on days with mild temperatures (around 14 to 21°C).
The research was based on data from the Mortality Information System (SIM) of the Unified Health System (SUS) and the Brazilian Gridded Daily Meteorological Data Set (BR-DWGD).
Professor at ISC/UFBA and Cidacs collaborator, Ismael Silveira explains that international research has already indicated that young children are more vulnerable to climate extremes. But there was little evidence in countries with tropical climates.
“Brazil has continental dimensions and strong socioeconomic inequality, which makes it a ‘natural laboratory’ for investigating climate impacts. The coverage and quality of death data and the use of robust statistical methods helped overcome this gap”, says Silveira.
Children are more vulnerable to the effects of temperature changes because their bodies have not yet fully developed thermal regulation mechanisms. On hotter days, risks include heatstroke, dehydration, kidney problems, respiratory and infectious diseases. In the cold, hypothermia can occur, which triggers respiratory and metabolic complications, and favors an increase in infections.
Brazil presents regional variations in terms of climate impacts. The data indicates that cold-related mortality of children under five years of age reached the highest increase (117%) in the south of the country. Heat-related mortality was higher in the Northeast (102%).
High rates of child deaths continue to be concentrated in the North, Northeast and Central-West regions. These regions have greater socioeconomic vulnerability and worse access to basic infrastructure, such as sanitation and adequate housing. Rising temperatures pose an additional threat.
