The Rising Heat is Sapping India’s Productivity

Temperature impacts on worker productivity may be more pronounced and widespread in sectors such as agriculture because exposure may be higher and adaptation possibilities more limited.

A construction worker in New Delhi Credit Francois Decaillet

A construction worker in New Delhi Credit Francois Decaillet

Life isn’t easy for rickshaw puller Ajoy Mandal. In summers, it becomes intolerable. “Working in the heat has become virtually impossible but I have no choice,” says Mandal, who has been ferrying passengers on his leased rickshaw for the past three years in Noida on the outskirts of Delhi. “The skin burns even in the evenings.”

Mandal is one among the millions of outdoor workers in India who are finding it difficult to work as temperatures rise every year, hurting productivity and health. This has a direct impact on the economy, a fact recognised only recently. A major report last month by the United Nations Development Programme (UNDP) said levels of heat in many tropical locations are already very high with respect to thermal tolerances, even for acclimatised populations. In places across India, temperatures are frequently higher than 40 ºC, even breaching the 50º-mark in quite a few places in Odisha and Rajasthan.

“The lowest income-bracket work – heavy labour and low-skill agricultural and manufacturing jobs – are among the most susceptible to climate change,” according to the UNDP. Agriculture is the biggest employer in India (54.6% of the working population, or 263.2 million people), followed by manufacturing and construction work. Working out in the sun is common for the majority of working Indians. Then, there are millions in industry and services, many of whom work in urban heat-islands. So when it gets too hot to work, livelihoods and economic growth take a hit.

A number of studies on industrial workers have shown that workplace heat has a strong negative impact on productivity, or even the ability to work. When physical activity is high in a hot working environment, a worker is at risk of increased core-body temperatures (above 38 ºC), diminished physical work capacity and mental task ability, increased risk of accidents and eventually heat exhaustion – conclusions reached by three health scientists in a paper published in 2009.

One result of climate change is a reduced work-capacity in heat-exposed jobs, according to Tord Kjellstrom, one of the three and an expert on heat and occupational health who has studied industrial workers in India. He is also the lead technical author of the UNDP report.

The economic impact of global warming has been documented mostly through its effect on farm output, where high temperatures are associated with low crop-yields. However, the impact of heat on workplace productivity is a more neglected aspect of climate change.

“We estimate output declines of between 4% and 9% per degree on days when wet bulb globe temperatures (WBGT) are above 27 degrees Celsius,” wrote E. Somanathan, Rohini Somanathan, Anant Sudarshan and Meenu Tewari said in a 2015 working paper. WBGT is a measure of heat stress in direct sunlight, which takes into account temperature, humidity, solar radiation and wind speed, among others. It differs from the heat index, which considers temperature and humidity and is calculated for shady areas.

“Based on our estimates, this warming may have reduced manufacturing output in 2009 by 3% relative to a no-warming counterfactual, an annual economic loss of over USD 8 billion. These estimates are conservative because they do not account for the costs of incurred adaptation or capture the impacts of local urban heat islands,” the researchers add.

Satellite images of Indian metropolitan areas show the presence of urban hotspots with temperatures 5 ºC above that of the surrounding countryside. According to Kjellstrom’s 2009 paper, “Modern urban development can add several degrees to local temperatures through heat absorption in concrete buildings, road tar etc.”

Temperature impacts on worker productivity may be even more pronounced and widespread in sectors such as agriculture and construction across the world, simply because exposure may be higher and adaptation possibilities more limited, according to Somanathan and his colleagues.


Outdoor work is particularly affected by the extra heat load from solar radiation, but researchers say millions of indoor workers are also affected as many factories and workshops in tropical countries lack efficient cooling systems. In a survey of Chennai workplaces, Karin Lundgren, Kalev Kuklane and Vidhya Venugopal found that all the indoor workplaces surveyed had very high heat-exposure in the summer months, often exceeding international WBGT limits.

The effects of rising heat may lead to more than 10% loss of productive work in South Asia and West Africa, a 2014 paper said. “As an example, the annual daylight work hours lost in India (the largest country in South Asia) may be 5% more in 2050 than in 1975.”

This article was originally published on www.indiaclimatedialogue.net.