In late June a brutal heat wave settled over the Sindh province in Pakistan and remained there for one week. High humidity, and scorching temperatures that reached 113 degrees, made conditions dangerous, particularly in Karachi, the world’s largest Muslim city, where—to compound the danger—millions were fasting for Ramadan.
Like all big cities, Karachi is an urban heat island. Its steel, concrete, and asphalt attract the sun’s warmth, and its thick bands of pollution trap it, depriving residents of natural cooling at night and leaving residents more vulnerable to the baking hot air.
Karachi is also a rapidly growing and developing city. Use of air conditioners is surging, and people increasingly rely on modern conveniences such as personal computers, flat-screen televisions, and mobile phones. In Karachi, as in cities throughout the world, demand for energy often outstrips supply on hot days, and unprecedented demand during the heat wave led to recurrent power outages and loss of water in high-rise buildings that depend on electrical pumps.
Karachi, again like so many big cities, is also sharply divided, with pockets of affluence as well as rampant poverty. Predictably, the city’s poorest areas experienced disproportionately long power outages and diminished access to water during the heat wave. Although residents took to the streets in protest, the government was unable to respond to those most in need. They were, as usual, left to take care of themselves.
The results were catastrophic: Provincial authorities report that, as of Wednesday, more than 65,000 people were admitted to hospitals for heat-related illnesses and that 1,250 people died from the heat in Karachi alone. The true human toll is likely far greater, because, as epidemiologists have shown, in typical heat waves many related deaths are never officially counted as such. Only later, if and when governments release mortality statistics for the duration of the disaster, can we compare the fatalities from this time period with those in previous years and calculate the “excess deaths” that the heat induced.
Using this technique, scientists have discovered that heat waves are far more lethal than we previously recognized. In 2003, for instance, a prolonged heat wave hit much of Europe. Initially, journalists reported that thousands had died in France but that its neighbors had avoided comparable damage. Later, however, one team of scholars found that roughly 70,000 people in excess of the norm perished across the continent, with nations including Italy, Germany, and England experiencing far higher mortality than officials had acknowledged. In May, India reported more than 2,300 heat deaths from weather so hot it melted roads in Delhi. Odds are the disaster was significantly more deadly than that.
Our vulnerability to heat waves is worrisome because, as climate scientists warn, global warming will likely generate hotter, more frequent, and longer heat waves, which in turn will produce more heat-related illness and death. In typical years, heat waves already kill more Americans than hurricanes, tornadoes, earthquakes, and floods. But because they’re neither visually spectacular nor do they generate expensive property damage, they receive far less public attention than other extreme weather systems. As the planet warms, though, reckoning with heat becomes urgent—in both the developed and developing countries alike.
Fortunately, scientists and policymakers have made major advances in managing heat emergencies, both during acute disasters and during the slow motion disaster of climate change.
Dealing with heat waves is relatively easy. We can’t know exactly where an earthquake, tornado, or hurricane will hit, or how powerful it will be. But meteorologists can identify dangerous heat long before it arrives, which means governments and media can repeatedly alert citizens, communities, and health care providers about the impending danger and offer specific instructions on how to protect those most at risk.
It’s especially important that governments urge businesses and consumers to reduce overall demand for energy during heat waves—which means, yes, using air conditioning only when necessary. Today, from Queens to Karachi, electrical grids routinely fail when we need them most. It’s hard to get widespread compliance, but without some collective sacrifice, everyone winds up sweating in the dark.
Not everyone suffers from heat similarly, however, and research shows that some people are far more vulnerable than others. They’re typically old and poor, homeless or socially isolated, physically frail, or, in developing nations and in agricultural regions of the first world, relegated to do low-wage physical labor despite the temperature. It’s not yet clear exactly who died last week, but several sources, including a representative for a foundation that runs an ambulance service and Karachi’s largest morgue, reported that homeless and sick people were the primary victims, followed by the elderly. Whether it’s Pakistan, France, India, or the United States, the profile of heat victims is strikingly similar, which should allow states to target preparation and relief efforts with great precision.
In fact, few states do this—not because of insufficient resources, but because of low public awareness and a weak political will to help the vulnerable. It’s not very expensive to enlist residents, community organizations, and government employees in a public campaign to help poor, old, and isolated people, nor is it excessively burdensome to require employers to reduce hours for manual laborers in dangerous weather.
Chicago, where a devastating heat wave killed 739 people exactly 20 years ago this summer, has since developed an exemplary heat emergency response that integrates most of these measures. Chicago is by no means immune from another catastrophe, but during heat waves residents there are far better protected than they were two decades ago. Paris and several other European cities shored up their heat plans after the 2003 catastrophe, too, and the record-breaking temperatures hitting the continent this week will test their effectiveness.
Managing short spells of extreme heat is one thing; dealing with the larger heat emergency is another. No nation, not the U.S. or France or Pakistan, has come up with an adequate plan for the kinds of heat waves that climate scientists fear. Imagine conditions similar to what Chicago saw in 1995, if not hotter and more humid, that lasted for one or two weeks rather than three days. The power grid would never withstand the stress. There’s no plan for getting water to people in high-rise apartment buildings when energy goes out for days. Businesses would close. Hospitals couldn’t handle the surge of emergency patients, and the health system could easily collapse. There are no solutions to these problems in the typical urban heat plan, but global warming should force us to address them directly.
More difficult, still, is the greater challenge posed by global warming, urbanization, and rising inequality. These emerging conditions create a formula for disaster that is always present but difficult to perceive.
The outdated infrastructure that cities around the world depend on for water, electricity, and communications make these conditions even more potent. People in even the most affluent societies expect to lose power on the summer’s hottest days, and those in developing cities expect to lose far more. Nature, or at least the new, hotter nature that we humans have made, has the upper hand.
Heat waves are lethal. But they are also resources, because they help us identify dangerous underlying conditions that we still have time to manage and improve. The real question is what we will do to protect ourselves and ensure our future well-being when the weather breaks.
This article is part of Future Tense, a collaboration among Arizona State University, New America, and Slate. Future Tense explores the ways emerging technologies affect society, policy, and culture. To read more, visit the Future Tense blog and the Future Tense home page. You can also follow us on Twitter.
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