Nearly a third of the world’s population is now exposed to climatic
conditions that produce deadly heatwaves, as the accumulation of
greenhouse gases in the atmosphere makes it “almost inevitable” that
vast areas of the planet will face rising fatalities from high
temperatures, new research has found.
Climate change
has escalated the heatwave risk across the globe, the study states,
with nearly half of the world’s population set to suffer periods of
deadly heat by the end of the century even if greenhouse gases are
radically cut.
“For heatwaves, our options are now between bad or terrible,” said
Camilo Mora, an academic at the University of Hawaii and lead author of
the study.
The proportion of people at risk worldwide will grow to 48% by 2100
even if emissions are drastically reduced, while around three-quarters
of the global population will be under threat by then if greenhouse
gases are not curbed at all.
“Finding so many cases of heat-related deaths was mind blowing,
especially as they often don’t get much attention because they last for
just a few days and then people moved on,” Mora said.
High temperatures are currently baking large swaths of the south-western US, with the
National Weather Service (NWS) issuing an
excessive heat warning for Phoenix, Arizona, which is set to reach 119F (48.3C) on Monday.
The heat warning extends across much of Arizona and up through the
heart of California, with Palm Springs forecast a toasty 116F (46.6C) on
Monday and Sacramento set to reach 107F (41.6C).
“Dying in a heatwave is like being slowly cooked, it’s pure torture. The
young and elderly are at particular risk, but we found that this heat
can kill soldiers, athletes, everyone.”
The study, published in Nature Climate Change,
analyzed more than 1,900 cases of fatalities associated with heatwaves
in 36 countries over the past four decades. By looking at heat and
humidity during such lethal episodes, researchers worked out a threshold
beyond which conditions become deadly.
This time period includes the European heatwave of 2003, which fueled
forest fires in several countries and caused the River Danube in Serbia
to plummet so far that submerged second world war tanks and bombs were
revealed. An estimated 20,000 people died; a
subsequent study suggested the number was as high as 70,000.
A further 10,000 died in Moscow due to scorching weather in 2010. In
1995, Chicago suffered a five-day burst of heat that resulted in more
than 700 deaths.
Read more: A third of the world now faces deadly heatwaves as result of climate change | Environment | The Guardian