(CNN) — Doctors have long raised alarm about the potential health risks of climate change, but it turns out that children are particularly vulnerable.
Children are estimated to bear 88% of the burden of disease related to climate change, according to a paper published Tuesday in the journal Pediatrics.
The new paper highlights some studies on the implications of climate change for children’s health and then calls for the world to better prepare for these health risks, not just in the future but in the present.
“We already have seen the impacts,” said Dr. Kevin Chan, chairman of pediatrics at Memorial University and head of child health at Eastern Health in Canada, who co-authored the paper.
Chan pointed to Hurricanes Katrina, Harvey and Irma as examples of climate change-related weather events that have affected children’s health, along with extreme heat waves and emerging infectious pathogens such as the Zika virus.
During pregnancy, Zika infection can cause a serious birth defect called microcephaly, a condition in which a baby’s head is smaller than expected and the brain has not developed properly. There is no treatment for microcephaly that can return a child’s head to a healthy size or shape.
Alerts of an outbreak of Zika, spread mostly by mosquitoes, emerged in 2015 and continued through 2016. Some studies suggest that increased climate instability has contributed to the emergence and spread of mosquito-borne infections like Zika.
“Absolutely, that was one that disproportionately affected children,” Chan said of Zika.
“The basic message is that climate change is occurring, and I think it disproportionately affects the most vulnerable populations, and that includes children,” he said.
In the new paper, Chan and co-author Dr. Rebecca Pass Philipsborn, a member of the pediatrics faculty at the Emory University School of Medicine, cited a separate study that found that deaths due to diarrhea, malaria and nutritional deficiencies among children younger than 5 accounted for 38%, 65% and 48% of all global deaths, respectively, in 2015.
That study was published in The Lancet in 2016. The new study reports that those causes of death can be climate-sensitive.
For instance, certain changes in climate can make it more suitable for the transmission of malaria, a mosquito-borne disease caused by a parasite transmitted through the bite of infected mosquitoes.
Similarly, climbing temperatures have been tied to an increased incidence of waterborne bacterial infections that cause diarrhea. When compared with a future without climate change, an estimated 48,000 additional deaths due to diarrheal illness are projected among children younger than 15 by 2030, according to the World Health Organization.
As for nutritional deficiencies, about 95,000 additional deaths due to childhood undernutrition are projected for 2030, according to the WHO. Extremely high seasonal temperatures and extreme weather events could damage crops, impacting the food supply and thus childhood nutrition.
In their paper, Chan and Philipsborn also referenced studies on children’s vulnerability to extreme heat, droughts and air pollution.
A separate report, published last year by the Medical Society Consortium on Climate and Health, mapped how those climate change-related events and others threaten the health of people across the United States — and those threats can vary by region.
Dr. Mona Sarfaty, executive director of the Medical Society Consortium on Climate and Health and director of the program on climate and health at George Mason University’s Center for Climate Change Communication, said the the sources for the new Pediatrics paper are credible and well-known to experts on climate change and health.
“The danger to children is real and is already witnessed by physicians in the US,” said Sarfaty, who was not involved in the paper.
“Children suffer more heat impacts because they spend more time outside. They are more vulnerable to the heat-related increases in air pollution that come from fossil fuel exhaust, because their lungs are still developing. Outdoor play also makes them more prey to insect vectors carrying dangerous infections,” she said. “The doctors in our societies are seeing these problems today, and they will undoubtedly get worse if we don’t decisively address climate change.”
Though the new paper highlights the current body of research on climate change and children’s health, Chan said that more research could help physicians better understand and prepare for the health impacts of climate change.
“Specifically, what we wanted to highlight was, there’s very little research and evidence around children,” Chan said.
“A lot of the research is very, very broad and tends to look more at adult populations. I don’t think they factor in the specific impacts on children themselves, and I think more research is needed in that arena,” he said. “We really need more efforts into addressing climate change to protect our children.”
In 2015, the American Academy of Pediatrics published an updated policy statement on global climate change and children’s health, calling for health facilities to reduce their carbon and environmental footprints and for politicians to promote energy efficiency, among other recommendations.
“Climate change is a rising public health threat to all children in this country and around the world,” former academy President Dr. Sandra G. Hassink said in a news release at the time.
“Pediatricians have a unique and powerful voice in this conversation due to their knowledge of child health and disease and their role in ensuring the health of current and future children,” she said.