Rising temperatures will cause more deaths than
all infectious diseases – study
Poorer, hotter parts of the world will struggle to
adapt to unbearable conditions, research finds
Oliver
Milman in New York
@olliemilman
Tue 4 Aug
2020 08.00 BSTLast modified on Tue 4 Aug 2020 08.01 BST
The growing
but largely unrecognized death toll from rising global temperatures will come
close to eclipsing the current number of fatalities from all the infectious
diseases combined if planet-heating emissions aren’t constrained, a major new
study has found.
Rising
temperatures are set to cause particular devastation in poorer, hotter parts of
the world that will struggle to adapt to unbearable conditions that will kill
increasing numbers of people, the research has found.
The
economic loss from the climate crisis, as well as the cost of adaption, will be
felt around the world, including in wealthy countries.
In a
high-emissions scenario where little is done to curb planet-heating gases,
global mortality rates will be raised by 73 deaths per 100,000 people by the
end of the century. This nearly matches the current death toll from all infectious
diseases, including tuberculosis, HIV/Aids, malaria, dengue and yellow fever.
The
research used an enormous global dataset of death and temperature records to
see how they are related, gathering not only direct causes such as heat stroke
but also less obvious links such as a surge in heart attacks during a heatwave.
“A lot of
older people die due to indirect heat affects,” said Amir Jina, an
environmental economist at the University of Chicago and a co-author of the
study, published by the National Bureau of Economic Research. “It’s eerily
similar to Covid – vulnerable people are those who have pre-existing or
underlying conditions. If you have a heart problem and are hammered for days by
the heat, you are going to be pushed towards collapse.”
Poorer
societies that occupy the hottest areas of the world are set to suffer worst.
As already baking temperatures climb further this century, countries such as
Ghana, Bangladesh, Pakistan and Sudan face an additional 200 or more deaths per
100,000 people. Colder, richer countries such as Norway and Canada, meanwhile,
will see a drop in deaths as fewer and fewer people perish due to extreme cold.
“You see
the really bad impacts at the tropics,” said Jina. “There’s not one single
worldwide condition, there’s a lot of different changes with poorer people much
more affected with limited ability to adapt. The richer countries, even if they
have increases in mortality, can pay more to adapt to it. It’s really the
people who have done the least to cause climate change who are suffering from
it.”
Huge
heatwaves have roiled the US, Europe, Australia, India, the Arctic and
elsewhere in recent years, while 2020 is set to be hottest or second hottest on
record, in line with the longer-term trend of rising temperatures. The deaths
resulting from this heat are sometimes plain enough to generate attention, such
as the that 1,500 people who died in France from the hot temperatures during
summer last year.
Within richer countries, places already used to the heat will have an adaptation head start on areas only now starting to experience scorching conditions. “A really hot day in Seattle is more damaging than a really hot day in Houston because air conditioning and other measures are less widespread there,” said Bob Kopp, a co-author and climate scientist at Rutgers University.
“It’s not
going to be free for Seattle to get the resilience Houston has. Obviously in
poorer countries the situation is much worse. Climate change is a public health
issue and and equality issue.”
The
economic cost of these deaths is set to be severe, costing the world 3.2% of
global economic output by the end of the century if emissions aren’t tamed.
Each ton of planet-warming carbon dioxide emitted will cost $36.60 in damage in
this high-emissions world, the researchers calculated.
This worst-case
scenario would involve emissions continue to grow without restraint, causing
the average global temperature increase to surpass 3C by 2100. The world has
heated up by about 1C, on average, since the dawn of mass industrialization, an
increase scientists say is already fueling increasingly severe heatwaves,
wildfires, storms and floods.
A more
moderate path, where emissions are rapidly cut, will see temperature-related
deaths less than a third of the more severe scenario, the researchers found.
The economic costs will be significantly lower, too.
“It’s
plausible that we could have the worst case scenario and that would involve
drastic measures such as lots of people migrating,” said Jina. “Much like when
Covid overwhelms a healthcare system, it’s hard to tell what will happen when
climate change will put systems under pressure like that. We need to understand
the risk and invest to mitigate that risk, before we really start to notice the
impacts.”
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