[Extreme heat can kill, as it did by the dozens in Pakistan in May. But as many of South Asia’s already-scorching cities get even hotter, scientists and economists are warning of a quieter, more far-reaching danger: Extreme heat is devastating the health and livelihoods of tens of millions more.]
By
Somini Sengupt
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A
construction site in New Delhi. For laborers, taking time off means lost wages.
Credit
Saumya Khandelwal for The New York Times
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She had traveled for 26 hours in a hot oven
of a bus to visit her husband, a migrant worker here in the Indian capital. By
the time she got here, the city was an oven, too: 111 degrees Fahrenheit by
lunchtime, and Rehmati was in an emergency room.
The doctor, Reena Yadav, didn’t know exactly
what had made Rehmati sick, but it was clearly linked to the heat. Dr. Yadav
suspected dehydration, possibly aggravated by fasting during Ramadan. Or it
could have been food poisoning, common in summer because food spoils quickly.
Dr. Yadav put Rehmati, who is 31 and goes by
one name, on a drip. She held her hand and told her she would be fine. Rehmati
leaned over and retched.
Extreme heat can kill, as it did by the
dozens in Pakistan in May. But as many
of South Asia’s already-scorching cities get even hotter, scientists and
economists are warning of a quieter, more far-reaching danger: Extreme heat is
devastating the health and livelihoods of tens of millions more.
If global greenhouse gas emissions continue
at their current pace, they say, heat and humidity levels could become
unbearable, especially for the poor.
It is already making them poorer and sicker.
Like the Kolkata street vendor who squats on his haunches from fatigue and
nausea. Like the woman who sells water to tourists in Delhi and passes out from
heatstroke at least once each summer. Like the women and men with fever and
headaches who fill emergency rooms. Like the outdoor workers who become so weak
or so sick that they routinely miss days of work, and their daily wages.
“These cities are going to become unlivable
unless urban governments put in systems of dealing with this phenomenon and
make people aware,” said Sujata Saunik, who served as a senior official in the
Indian Ministry of Home Affairs and is now a fellow at the Harvard University
School of Public Health. “It’s a major public health challenge.”
Indeed, a recent analysis of climate trends
in several of South Asia’s biggest cities found that if current warming trends
continued, by the end of the century, wet bulb temperatures — a measure of heat
and humidity that can indicate the point when the body can no longer cool
itself — would be so high that people directly exposed for six hours or more
would not survive.
In many places, heat only magnifies the more
thorny urban problems, including a shortage of basic services, like electricity
and water.
For the country’s National Disaster
Management Agency, alarm bells rang after a heat wave struck the normally hot
city of Ahmedabad, in western India, in May, 2010, and temperatures soared to
118 degrees Fahrenheit, or 48 Celsius: It resulted in a 43 percent increase in
mortality, compared to the same period in previous years, a study by public
health researchers found.
Since then, in some places, local
governments, aided by the Natural Resources Defense Council, an advocacy group,
have put in place simple measures. In Ahmedabad, for instance, city-funded vans
distribute free water during the hottest months. In the eastern coastal city of
Bhubaneswar, parks are kept open in afternoons so outdoor workers can sit in
the shade. Occasionally, elected
officials post heat safety tips on social media. Some cities that had felled trees for
construction projects are busy trying to plant new ones.
The science is unequivocally worrying. Across
the region, a recent World Bank report concluded, rising temperatures could
diminish the living standards of 800 million people.
Worldwide, among the 100 most populous cities
where summer highs are expected to reach at least 95 degrees Fahrenheit by
2050, according to estimates by the Urban Climate Change Research Network, 24
are in India.
Rohit Magotra, deputy director of Integrated
Research for Action and Development, is trying to help the capital, Delhi,
develop a plan to respond to the new danger. The first step is to quantify its
human toll.
“Heat goes unreported and underreported. They
take it for granted,” Mr. Magotra said. “It’s a silent killer.”
On a blistering Wednesday morning, with the
heat index at 111 degrees Fahrenheit, he and a team of survey takers snaked
through the lanes of a working-class neighborhood in central Delhi. They
measured temperature and humidity inside the brick-and-tin apartments. They
spoke to residents about how the heat affects them.
“Only by 4 a.m., when it cools down, can we
sleep,” a woman named Kamal told him. Her husband, a day laborer, suffered
heatstroke this year, missed a week’s work, and, with it, a week’s pay.
A shopkeeper named Mohammed Naeem said that
while he managed to stay cool in his ground-floor space, his father’s blood
pressure rose every summer, as he sweltered in their top floor apartment all
day.
Through the narrow lanes all morning, young
men hauled stacks of paper to a printing plant that operated on the ground
floor of one house. A tailor sat cross-legged on the floor, stitching lining
onto a man’s suit. A curtain of flies hung in the air.
A woman named Abeeda told Mr. Magotra that
she helped her husband cope during the summer by stocking glucose tablets in
the home at all times. Her husband works a house painter. Even when he is nauseous
and dizzy in the heat, he goes to work, she said. He can’t afford not to.
Across town, workers covered their faces with
bandannas as they built a freeway extension for Delhi’s rapidly growing number
of cars. The sky was hazy with dust. Skin rash, dry mouth, nausea, headaches:
These were their everyday ailments, the construction workers said. So
debilitating did it get that every 10 to 15 days, they had to skip a day of
work and lose a day’s pay.
Ratnesh Tihari, a 42-year-old electrician,
said he felt it getting hotter year by year. And why would that be surprising?
He pointed his chin at the freeway extension he was helping to build. “It’s a
fact. You build a road, you cut down trees,” he said. “That makes it hotter.”
Worldwide, by 2030, extreme heat could lead
to a $2 trillion loss in labor productivity, the International Labor
Organization estimated.
Delhi’s heat index, a metric that takes
average temperatures and relative humidity into account, has risen sharply — by
0.6 degrees Celsius in summer and 0.55 degrees during monsoons per decade
between 1951 and 2010, according to one analysis based on data from 283 weather
stations across the country.
Some cities are getting hotter at different
times of year. The average March-to-May summertime heat index for Hyderabad had
risen by 0.69 degrees per decade between 1951 and 2010. In Kolkata, a delta
city in the east, where summers are sticky and hot anyway, the monsoon is
becoming particularly harsh: The city’s June-September heat index climbed by
0.26 degrees Celsius per decade.
Joyashree Roy, an economist at Jadavpur
University in Kolkata, found that already, most days in the summer are too hot
and humid to be doing heavy physical labor without protection, with wet-bulb
temperatures far exceeding the thresholds of most international occupational
health standards.
And yet, walk through the city on a stifling
hot day in June, and you’ll find people pedaling bicycle rickshaws, hauling
goods on their heads, constructing towers of glass and steel. Only a few
people, like herself, Dr. Roy pointed out, are protected in air-conditioned
homes and offices. “Those who can are doing this. Those who can’t are becoming
worse,” she said. “The social cost is high in that sense.”
Researchers are tinkering with solutions.
In Ahmedabad, city funds have been used to
slather white reflective paint over several thousand tin-roofed shanties,
bringing down indoor temperatures.
In Hyderabad, a similar effort is being
tested. A pilot project by a team of engineers and urban planners covered a
handful of tin-roofed shacks with white tarpaulin. It brought down indoor
temperatures by at least two degrees, which was enough to make the intolerable
tolerable. Now they want to expand their cool-roof experiment to a
1-square-kilometer patch of the city, installing cool roofs, cool walls and
cool sidewalks, and planting trees. Their main obstacle now: funding.
Rajkiran Bilolikar, who led the cool-roof
experiment, has a personal stake in the project. As a child, he would visit his
grandfather in Hyderabad. There were trees all over the city. It was known for
its gardens. He could walk, even in summer.
Now a professor at the Administrative Staff
College of India in Hyderabad, Mr. Bilolikar can’t walk much. His city is
hotter. There are fewer trees. Air-conditioners have proliferated but they spew
hot air outside.
Mr. Bilolikar says it’s hard to persuade
policymakers, even the public, to take
heat risk seriously. It’s always been hot in Hyderabad. It’s getting hotter
slowly, almost indiscernibly. Heat, he says, is “a hidden problem.”
At home, he had resolved not to use his
air-conditioner. Through his open windows, though, his neighbor’s machine blew
hot air into his apartment. His three-year-old daughter became so overheated
that her skin was hot to touch. Reluctantly, he shut his windows and turned his
machines on.