PARIS • More than 150 million vulnerable people worldwide were exposed to potentially life-threatening heatwaves last year, a study said yesterday, warning that climate change posed an unprecedented global health risk.
In a worldwide stocktake of public health trends, dozens of international agencies said people over 65, those living in large cities, and sufferers of heart and lung disease were all at heightened risk of death or disability from extreme heat.
The warning came as the United Nations' meteorological body said that the past four years, including this year, were the four warmest on record.
Globally, a total of 153 billion work hours were lost due to heat exposure last year, including 7 per cent of all labour time in India, the authors of the study said, adding that the cost of keeping people safe from heatwaves was likely to balloon as our planet warms.
The outlook is particularly dire for Europe and the eastern Mediterranean, where mounting temperatures and an ageing population produced a "perfect storm" of risk factors, according to the study's lead author.
"For a very, very long time, we have thought about climate change as something that affects the environment some time in 2100," Dr Nick Watts, executive director of The Lancet Countdown on Health and Climate Change, told Agence France-Presse.
"When you look at climate change as a public health issue, it really turns it on its head. It isn't just affecting polar bears or rain forests, it's something that affects communities, children, families in the UK and Europe and around the world."
The study team comprised experts from 27 institutions worldwide who mapped a variety of climate and health trends.
Dr Watts and his team found that while global temperatures have risen 0.3 deg C since the mid-1980s, for those most at risk of heat exposure, the average temperature rise experienced was more than double, at 0.8 deg C.
This was attributed to a mixture of factors, including migration to cities - vulnerability to heatwaves through the "urban heat island effect" - as well as more extreme localised heat as climate change wreaks havoc with our weather systems.