Climate Change Commission head Rodd Carr discusses climate change reduction targets with student activists in Christchurch. Video / Frank Film
A major new study has linked rising temperatures over the past two decades to health risks in Kiwi kids.
The University of Auckland research shows the danger of hospitalisation jumps when temperatures hit 24.1C.
The researchers say their findings prompt the need for planning for a hotter future under climate change.
Temperatures rising under climate change are putting our youngest increasingly at risk of life-long health problems, scientists warn.
In a major new study, researchers drew on data from nearly 650,000 hospital cases involving children under five to link daily high temperatures with increased admissions.
They found that kids under 5 were at significantly higher risk of needing hospital care when temperatures hit 24.1C – with Māori, Pacific, and Asian children disproportionately at danger.
The study’s lead author, Dr Hakkan Lai of the University of Auckland, explained young people were especially more affected than adults because their bodies gained heat faster.
“Since their bodies are still growing, they can be even more sensitive to heat when exposed to things like pollution, allergens, and germs at the same time,” Lai said.
Young children also might not show signs of discomfort – even when very hot and dehydrated – so needed extra protection, he said.
“If help comes too late, they can get very sick, which can be tough for families and can affect the children for their whole lives.”
Those life-long health problems ranged from infectious diseases, to blood and immune disorders, to issues with kidneys and skin.
“We can see hospital admissions increase from the first day of high temperature – after that, pronounced delayed effects are still evident three weeks later.”
The study, which analysed data from children born between 2000 and 2019, also observed a pattern whereby the risk of hospital admissions held steady before the mercury hit 24.1C.
At the same time, however, the relative risk of heat stress wasn’t uniform for all kids around New Zealand.
“Preschoolers’ vulnerability to heat stress appears to be highly sensitive to daily temperature changes and is unevenly distributed across the population.”
The new research found young children were at significantly higher risk of needing hospital care when temperatures hit 24.1C. Photo / Steven McNicholl
Geography played a part: young children living in Central Otago, Central Canterbury and the East Coast, and those in densely populated areas, had greater sensitivity to daily temperature swings than those in other areas.
There were also stark ethnic, sex and socio-economic differences, with Pacific, Asian and Māori children more frequently turning up at hospital on those extra hot days than Pākehā kids.
Conversely, children new to New Zealand were less sensitive to heat – but much more sensitive to cold.
The researchers also found boys appeared less sensitive to daily temperature than girls, while kids living in homes owned by caregivers seemed more at risk than those in rental properties.
In all, the research indicated that nearly 300 preschool-aged kids were admitted to hospital each year between 2013 and 2019 because of heat effects.
Their modelling predicted that the number of admissions would continue to climb as the planet warmed – with clear implications for healthcare, housing and urban design.
In Auckland, that could be occurring on a dozen more days by 2040 – and nearly 50 more days by 2099.
Over the past few summers, MetService has been trialling region-specific “heat alerts” to warn people of unusually hot temperatures.
Waikato University climate scientist Dr Luke Harrington – a co-author of the latest study who’s also been working with MetService – didn’t expect the new findings to change those alerts.
“This new research only focuses on children under 5 and so shows only a small part of the challenge we face with extreme heat,” Harrington said.
“But it does provide clear evidence to justify the expansion of the heat alert pilot scheme into a formal heatwave early warning system, like they have in Australia and the UK.”
Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.
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