Lethal Heating: 10/21/25

21/10/2025

How climate change risks children’s health - Lethal Heating Editor BDA

Key Points

Children are physiologically more vulnerable to climate hazards and pollution.^[1]
Air pollution, heat, infectious diseases and food insecurity are primary pathways of harm.^[2]
Early-life exposure to poor air quality predicts poorer health in adolescence and beyond.^[3]
Paediatricians and public-health bodies are increasingly urging climate action for child health.^[7]
Adaptation measures such as cool schools, air filtration and nutrition programs reduce risk.^[5]
Low-income and marginalised children face the largest and most persistent impacts.^[6]

Climate change is changing environments where children grow, learn and play.

Children are uniquely exposed because their organs and immune systems develop rapidly, and they breathe more air per kilogram of body weight than adults.

Air pollution from fossil fuels, wildfire smoke and rising ozone combines with heat, changing disease patterns and food insecurity to produce multiple health threats for young people.

Research now links early-life exposure to polluted air with worse respiratory health, slower growth and reduced well-being later in life.

Heatwaves and extreme weather events increase the risk of dehydration, heat illness and injury among infants and school-age children.

Vector and waterborne diseases are shifting their ranges and seasonality, increasing infections in some child populations.

Mental health and learning suffer when children experience displacement, family stress or school disruption after climate disasters.

Medical associations and paediatricians are increasingly framing climate action as a child-health priority and calling for both mitigation and adaptation.

Without stronger action and equity-focused policies, children in disadvantaged communities will shoulder the greatest burdens for decades to come.^[6]

The unique vulnerability of children

Children’s bodies and behaviours make them more susceptible to environmental hazards compared with adults.

They inhale more air relative to body size, drink more water per kilogram and spend more time outdoors, increasing pollutant and pathogen exposure.

Early-life exposures occur while lungs, brains and immune systems are forming, creating the potential for lifelong impacts from short exposures.

Global health organisations highlight that a disproportionate share of climate-related disease burden falls on children and adolescents worldwide.^[1]

Air pollution and respiratory impacts

Air pollution is a leading and well-documented pathway by which climate change harms children’s health.

Warmer temperatures increase ground-level ozone and can worsen particulate pollution during stagnation and wildfire events.

Numerous studies link childhood exposure to fine particulate matter and ozone with increased asthma, poorer lung growth and higher respiratory hospital admissions.

A recent cohort study found that children exposed between ages two and four to higher particulate levels were more likely to report worse health at age seventeen, illustrating long-term consequences of early exposure.^[3]

Cleaner energy and transport policies reduce air pollution and deliver rapid benefits for child respiratory health and development.^[13]

Heat, extreme weather and direct physical harm

Heatwaves are becoming more frequent and more intense in many regions, raising risks for dehydration, heat exhaustion and heatstroke in children.

Infants and very young children are less able to regulate body temperature and rely on caregivers and safe settings to avoid dangerous heat exposure.

Extreme weather also disrupts water and sanitation services and health care access, amplifying risks of infection and injury.

Regional reports note a steady rise in child exposures to heatwaves and related admissions, prompting calls for heat-safe school protocols and cooling interventions.^[15]

Infectious disease, water safety and nutrition

Shifts in rainfall, temperature, and flooding change the habitats of disease vectors and the seasonality of some infections that affect children.

Diarrhoeal diseases and waterborne outbreaks follow floods and service breakdowns and are a major cause of morbidity in young children in many countries.

Crops and food systems disrupted by drought and extreme weather reduce food availability and diversity, increasing undernutrition and stunting risks.

Systematic reviews show associations between climate-sensitive events and rises in diarrhoeal disease, malnutrition, and growth faltering in children across impacted areas.^[8]

Mental health, learning and social impacts

Children affected by disasters often experience anxiety, depression and post-traumatic stress, which can impair learning and social development.

Displacement, school closures and parental stress undermine stable caregiving environments that children need to thrive.

Research after climate disasters consistently documents elevated rates of mental-health symptoms in children and adolescents that can persist without support.

Community-based mental-health responses and school reintegration programs reduce long-term harms when deployed promptly after events.^[8]

Role of the medical community and allied actors

Paediatricians and public-health professionals are increasingly framing climate change as a clinical and policy concern for child health.

Clinical actions include screening for heat and smoke exposure, advising families on exposure reduction, and supporting vaccination and nutrition services that lower vulnerability.

Professional bodies urge policymakers to adopt health-centred climate mitigation such as clean-air standards and rapid decarbonisation to protect children now and in the future.^[7]

Schools, local councils and civil society provide adaptation measures such as early-warning systems, air-quality monitoring, cooling centres and nutrition support to reduce immediate risks.

Equity, evidence gaps and policy priorities

Equity must be central because socioeconomically disadvantaged children face higher exposure and lower capacity to adapt.

High-income countries may see improvements with policy changes, while many low-income settings lack infrastructure, increasing risks and long-term harms.

Researchers note important evidence gaps, especially long-term cohort data from under-researched regions and rigorous evaluation of interventions for children.^[10]

Priority policies include reducing fossil-fuel emissions for immediate air-quality gains, strengthening health systems, and investing in child-focused adaptation such as cool, ventilated schools and nutrition programs.^[16]

Outlook

The evidence is clear that climate change increases many threats to child health and development, and that many harms are preventable with timely action.

Protecting children demands integrated mitigation and adaptation that centre on health and equity, combined with improved surveillance and research.

When health professionals, educators, planners, and policymakers act together, they can cut risks and secure better health outcomes for today’s children and future generations.

References

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A crucial store of carbon in Australia’s tropical forests has switched from carbon sink to carbon source - The Conversation

The Conversation - Hannah Jayne Carle Adrienne Nicotra David Bauman
Michael N Evans Patrick Meir

Alexander Shenkin, Author provided (no reuse)

Authors

Hannah Jayne Carle
Postdoctoral Researcher in Tropical Forest Ecology, Hawkesbury Institute for the Environment, WSU, Australian National University
Adrienne Nicotra
Professor of Ecology and Evolution, Research School of Biology, Australian National University
David Bauman
Research Scientist in Plant Ecology, Institut de recherche pour le développement (IRD)
Michael N Evans
Professor in Earth’s Systems Science, University of Maryland
Patrick Meir
Chair of Ecosystem Science, University of Edinburgh

One approach to help fight climate change is to protect natural forests, as they absorb some atmospheric carbon released by burning fossil fuels and store large volumes of carbon.

Our new research on Australia’s tropical rainforests challenges the assumption that they will keep absorbing more carbon than they release.

We found that as climate change has intensified over the past half-century, less and less carbon has been taken up and converted to wood in the stems and branches of the trees in these forests.

Woody biomass is a large and relatively stable store of carbon in forests, and acts as an important indicator of overall forest health.

The effect has been so pronounced that the woody biomass of these forests has gone from being a carbon sink to a carbon source.

This means carbon is being lost to the atmosphere due to trees dying faster than it is being replaced by tree growth.

This is the first time woody biomass in tropical forests has been shown to switch from sink to source. Our research indicates the shift likely happened about 25 years ago.

It remains to be seen whether Australian tropical forests are a harbinger for other tropical forests globally.

Above ground biomass of trees in 20 long-term Australian rainforest research sites has gone from carbon sink to source as more trees die and decay. Andrew Ford, Author provided (no reuse)

What did we find?

Since 1971, scientists have tracked around 11,000 trees in 20 tracts of tropical rainforest in Australia’s far northeast, now part of the Queensland Permanent Rainforest Plots Network.

This 49-year research effort is one of the world’s longest and most comprehensive of its kind.

We analysed this long-term data and found a clear signal: woody biomass switched from being a carbon sink to a carbon source about 25 years ago.

Why? One reason: trees are dying twice as fast as they used to.

Tropical rainforest tree species are adapted to generally warm, wet conditions. As the climate changes, they are subjected to increasingly extreme temperatures and drier conditions.

These kinds of extreme climate events can damage wood and leaves, limiting future growth and leading to higher rates of tree death.

We also found tree deaths from cyclones reduced how much carbon these forests could absorb.

Cyclones in far north Queensland are projected to become increasingly severe under climate change. They are also likely to push further south, potentially affecting new areas of forest.

Isn’t carbon dioxide plant food?

Burning fossil fuels and other human activities have increased carbon dioxide levels in the atmosphere.

This should make it easier for plants to absorb CO₂ from the air, photosynthesise and grow.

Given this, Earth system models predict higher atmospheric CO₂ levels will stimulate plant growth and increase how much carbon tropical forests can take up.

Also, remote sensing shows the canopies of tropical forests on Australia’s east coast are about 20% greener than they were in the 1980s.

This suggests forest canopy growth has increased due to higher levels of CO₂ in the atmosphere. But this isn’t the whole picture.

Our data shows any potential increase in photosynthesis resulting in greener forest canopies has not translated to greater carbon storage in stems and branches.

The reason may be that tree growth can be limited by water, nutrients and heat.

Our work suggest that warmer and drier conditions have limited tree growth even as CO₂ concentration has increased.

In a separate study, scientists artificially increased CO₂ and found the extra carbon taken up by leaves wasn’t being stored as extra woody growth.

Rather, it was quickly released through roots and soil microbes.

Australian rainforest canopies have become greener. But heat, drying and water availability are taking their toll on carbon sink capacity. Alexander Shenkin, Author provided (no reuse)

What about other forest carbon stocks?

It will be challenging to find out whether these forests as a whole (including wood, roots, leaves and soils) have declined in carbon sink capacity.

The use of a specialised research tool known as eddy covariance towers could help, as these measure overall CO₂ movement into and out of ecosystems.

As of yet, only 15 years of this kind of data from three tropical Australian sites is available, which currently limits our ability to describe the fuller impact of climate change.

In any case, we know carbon stored in forest canopies and soils is often broken down and released back to the atmosphere faster than carbon in woody biomass.

So while Australia’s tropical rainforest carbon stores remain large, they may be less secure and reliable than in decades past.

Long term datasets are vital

When people visit Australia’s tropical rainforests, they can see intact stretches of biodiverse forest and large, carbon-rich trees.

It’s hard to directly see the changes we have detected – for now, they’re only visible in the data.

Without high-quality long-term datasets, this signal would have been almost impossible to detect.

Unfortunately, persistent funding shortages for long-term ecological monitoring threaten the continuity of these hugely valuable datasets.

Australia has the potential to assume a globally leading role in tropical ecosystem science.

In light of state and national biodiversity and emission reduction commitments, Australian governments should support continued monitoring of vital ecological research sites.

Tropical forests may not be saviours

The fact that woody biomass in Australia’s tropical rainforests is now a net source of carbon has major implications.

These findings challenge our future reliance on forests as natural absorbers of extra atmospheric carbon.

We don’t know yet whether all tropical forests will respond similarly.

Evidence on carbon sink capacity is mixed. Rainforests in South America are showing a decline while African rainforests are generally not.

Overall, the world’s tropical forests remain very significant stores of carbon and biodiversity. Their protection remains essential despite the climate risks they face.

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