Still, most studies suggest that the monsoon
rains will increase. “Uncertainty is not an excuse
[for inaction] at this point,” Oppenheimer says.
“People need to get moving.”
Land where it shouldn’t be
Lakshmi Murali lives with her husband and son in
a quiet, gated community, lush with jackfruit trees
and flowering hibiscus in Mumbai’s flood-prone
neighborhood of Andheri. Every June, as the rain
starts falling, she unplugs the electronics in their
ground floor apartment and moves her silk saris
out from under the bed.
Across the city, the rains rage against the glass
windows of luxury high-rises. Public transportation and street commerce come to a halt. Water
pounds the tin roofs of slum shanties where
about half of Mumbai’s 21. 4 million people live. A
sewage-tainted slurry burbles out of the city’s outdated and often-clogged drainage system, backing
up into rivers and creeks that then overflow into
homes and businesses.
Last year was particularly bad: In 24 hours,
about 33 centimeters of rain fell. “You had to see
it to believe it,” says Murali, a 54-year-old lawyer who is not related to the marine researcher
of the same name. Her building’s plumbing system failed, and the toilets overflowed. Residents
turned off their power for fear of getting electrocuted. As water rose inside their homes, Murali
and a few neighbors used an iron rod to smash a
hole through the wall surrounding their backyard
to let the water flow out.
“Today, we are young, and we say, ‘ Yeah, it’s OK,’ ”
Murali says. Even as such flooding worsens, she has
what some might call misplaced faith that things
will work out. “The state will work on building
enough infrastructure to keep the city alive and will
not allow the city to drown. Man will work against
what nature is proposing to do.”
Mumbai’s current predicament is partly due to
the power of engineering over nature. Large parts
of the city are built on land that, 300 years ago, was
mostly underwater. When the Portuguese settled
the region in the 16th century, they maintained
Mumbai as a sleepy collection of coastal islands.
But the British, who took over in 1661, reimagined
Mumbai as a contiguous landmass and created a
peninsula by filling in land gaps to connect the
islands even in the wet season.
“So many of these megacities are built on land
that is only artificially higher than sea level,
in places where landfilling took place,” says
Washington D.C.–based Susmita Dasgupta, the
lead environmental economist for the World
Bank’s Development Research Group.
Dasgupta was involved in the World Bank’s
first report in 2007 on how sea level rise might
affect national economies. The aim was to trigger
discussion and preparation for a possible future
economic catastrophe. She and her team offered
guarded impact estimates based on hypothetical
scenarios of between one and five meters of global
sea level rise, using satellite images of coastal outlines and local elevations.
In estimating potential economic losses, the
team considered an affected area’s population
multiplied by the country’s gross domestic product
per capita, but not infrastructure or property
assets. That report projected that one meter of
sea rise would cost the world 1. 3 percent of the
global economy. Applied to the forecast global
GDP for 2018, that comes to about $1.3 trillion,
not far from the estimates by Hallegatte’s team.
“But we wanted to raise the issue,” Dasgupta
says. She faced a wave of hostility and derision for
the effort. “Even bank colleagues were unhappy
about it, saying we were being alarmist and that
this kind of research was premature.” Eleven
years later, no one doubts the sea is rising.
Juggling the numbers
Amid the confusing tumble of scientific studies on
how climate change might raise flood risks, some
scientists have built online visual apps to help the
public understand what’s at stake.
One tool, by the U.S. National Oceanic and
Atmospheric Administration, shows past global
sea level trends based on tide gauges. But the app
does not give projections. And it relies on sometimes patchy data. For example, there are no read-
As monsoon rains
pounded Mumbai in July,
water poured down the
steps onto the beach in
front of Saif’s soda shop.