Hot in Hyderabad

Your questions about the Indian heat wave, answered.

Photo: AP/Ajit Solanki

A heat wave in India has killed nearly 1,400 people in the past week. I find myself in the western region of the country right now, where the high temperature was 100 degrees Fahrenheit today. Although that kind of heat was an inconvenience for the bicycle courier I watched trying to deliver a block of ice before it disappeared, it’s nothing compared to the suffocating heat in the southern part of the country, where most of the deaths and suffering are occurring. The mercury has climbed past 116 degrees in those areas, which is hot enough to melt roads.

Here’s what you need to know about the disaster, delivered with gratitude from the comfort of an air-conditioned hotel room in Pune.

Is this as bad as it gets?

Unfortunately, no. In or around January of every year, India’s prevailing winds change direction. Instead of bringing cool air from the northeast, they draw hotter air across the subcontinent from the south. The heat builds gradually until a few weeks after monsoon rains arrive, usually in early June. In the final weeks of this process, the heat is usually crippling. The highest recorded temperature in India was 123 degrees Fahrenheit, in the state of Rajasthan in 1956.

Heat-related deaths are, sadly, a routine part of Indian life. While this year’s death toll is worse than most, it is by no means unheard of. The 2003 heat wave killed 1,600 people; more than 1,300 died in 2010. The 2002 and 1998 editions each took more than 1,000 lives, and the death toll has reached the hundreds during many other years, such as 1978, ’79, ’85, ’86, ’91, and ’94.

Are the heat waves getting worse?

Yes, on average. Between 1901 and 2009, mean temperature across India rose by approximately one degree Fahrenheit. The average temperature during the pre-monsoon season, when the deadly heat waves are most likely to strike, has risen at an even faster rate. A 2004 study showed that heat waves were more intense during the 1990s than in the preceding two decades, and a 2003 paper noted that “death tolls from heat that were recorded over an entire summer some 10 years ago are now occurring in just one week.”

It’s important not to overinterpret these trends. Some of the country’s most extreme heat occurred decades ago, such as in 1926. Nor are all heat waves in recent years directly attributable to climate change. The disastrous 1998 occurrence, for example, was likely the result of El Niño.

The apparent increase in heat-related deaths is similarly complicated and not due entirely to climate change. India is urbanizing with incredible speed, with the rate of growth in cities more than doubling in recent years. By 2030, the country’s metropolises will host 590 million residents, far more than the populations of the United States, Mexico, and Canada combined. Even if the severity and number of heat waves remained steady, we’d see higher fatality rates because city dwellers are more likely to die in heat waves. Their living quarters are often cramped, with poor ventilation (especially in the sprawling slum communities), and the urban heat-island effect intensifies heat waves.

Improvements in public health and sanitation also play a role. In the past decade alone, Indian life expectancy has increased by an astonishing five years. That’s good news, but it increases heat-wave fatalities, as elderly people are especially vulnerable.

Those caveats aside, there is near universal agreement that anthropogenic climate change is contributing to India’s problem. A study published last year, for example, found that heat waves that used to be once-in-a-century events could happen every other year within a couple of decades.

What is the Indian government doing to help?

The central government defines a heat wave as sustained temperatures above 104 degrees Fahrenheit in the plains, or above 86 degrees Fahrenheit in the hills. (India’s hills have historically served as places of refuge from the searing heat, which is why the British built “hill stations” to house colonial authorities all over the subcontinent.) Temperatures in some parts of the country have neared 122 degrees this week, so this definitely qualifies.

In addition to urging people to stay out of the heat between 11 A.M. and 4 P.M., state governments in the hottest parts of the country have put hospitals on alert to treat heat-stroke victims. The government of Andhra Pradesh recently announced $1,500 payments to the families of victims.

Critics say this isn’t enough. The Indian news site FirstPost published an article entitled “A natural disaster nobody gives a damn about: Heat wave kills over 1,000 in Andhra Pradesh, Telangana.” The writer accuses the state governments of doing next to nothing and the federal government of lacking a plan for heat emergencies, which are hardly ever a surprise on the Asian subcontinent. The more mainstream Times of India offered a slightly less strident critique but nonetheless made several recommendations for how the government could improve its response.

Nongovernmental organizations are offering their own solutions. NRDC, for example, is working with the government of Ahmedabad and a coalition of academic and environmental groups to develop an early-warning system that will alert the city’s population to dangerous temperatures (disclosure). Other NGOs have opened drinking-water stations to people who lack convenient access to water.

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The heat wave is expected to last until later this week, when forecasted monsoons could bring some relief to the eastern and southern parts of the country. In the meantime, the death toll will likely continue to rise.

onEarth provides reporting and analysis about environmental science, policy, and culture. All opinions expressed are those of the authors and do not necessarily reflect the policies or positions of NRDC. Learn more or follow us on Facebook and Twitter.

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