Too hot to handle

The recent heatwave that has been broiling regions across India has not only obliterated temperature records – it has also left the population bewildered, as nobody can remember a heatwave occurring so early in the year.

India witnessed unprecedented heatwaves in March, a month before the weather bureau officially recognises the summer season, and the extremely high temperatures have continued into May.

This year saw the hottest March since the India Meteorological Department (IMD) began to maintain records 122 years ago, according to Mongabay-India, the environmental science news service. This follows the extreme heat in March last year, which was the third warmest March on record.

Photograph: iStock; credit: Umesh Negi

This year’s average maximum temperature for the month has already surpassed the previous record of 30.67 degrees Celsius in 2004. At an average maximum nationwide temperature of 33.10 degrees Celsius, March heralded the early onset of summer, a trend that is becoming the norm.

The IMD declared the country’s first heatwave on 11 March and, since then, several heatwaves have been declared ‘severe’.

The Meteorological Department declares a heatwave when the maximum temperature tops 40 degrees Celsius in plains. A heatwave is also considered to occur when temperatures reach at least 4.5 degrees above the normal average temperature.

A ‘severe’ heatwave is declared if the departure from normal temperature is more than 6.4 degrees, according to the IMD.

As well as the local weather conditions, one of the reasons the short-lived spring season has turned into a sweltering summer is the accumulation of greenhouse gases in the atmosphere. This is according to scientists who classify heatwaves as one of the earliest and most obvious impacts of climate change.

This year’s early heatwave comes as the average global temperature stands at 1.17 degrees Celsius higher than in 1850, the start of the Industrial Age.

Heatwaves have happened in the past, but human-induced climate change is making heatwaves longer, more extreme and more frequent, warn the experts.

An ongoing study by IMD and the Kottayam-based Institute for Climate Change Studies (ICCS) revealed that the number of heatwave days in India is increasing at a rapid pace every 10 years – from 413 in 1981–90 to 575 in 2001–10 and 600 in 2011–20.

Besides this, most of the 103 weather stations which are being studied for heatwave occurrences in India have shown either a jump or a significantly increasing trend in heatwave frequency between April and June during the 1961–2020 period.

One of the main factors for an increase in the number of heatwave days can be attributed to climate change, said Dr D S Pai, director at the Kottayam-based Institute for Climate Change Studies and former climate scientist at IMD Pune who was part of these studies.

Explaining that extreme temperature events like heatwaves are a key feature of global warming, he said: “The other factors for the extreme departure from normal maximum temperatures include local weather conditions, increasing concretisation, deforestation and changes in land use.”

Dr Pai added that there has been a decrease in the total number of ‘coldwave’ or severe coldwave days over the coldwave zone during the past three decades.

Global warming
In a written response to a question on heatwaves in parliament in January 2020, the then Earth Sciences minister Harsh Vardhan said the latest studies show an increase in temperatures as well as the occurrence of heatwaves in many parts of the country during recent years.

“One of the reasons for the increase in heatwaves is global warming associated with the increase in greenhouse gases like carbon dioxide, methane etc in the atmosphere,” he said.

At a webinar held in April this year, Mrutyunjay Mohapatra, head of IMD, said: “Extreme heat exposures are increasing because of climate change and pose a health and environmental emergency for the people of India.

“India Meteorological Department is committed to providing improved and upgraded early-warning heat forecasts that help hundreds of cities take protective action and create locally tailored measures to reduce the harms of extreme heat.”

Other experts at the event emphasised the need for a strong policy response to rising temperatures and heatwaves, including early warning systems, outreach strategies to improve community awareness and targeted measures to reach vulnerable populations.

Outdoor workers – such as daily wage workers, auto drivers, rickshaw pullers and street vendors – have been forced to change their work hours as unbearably hot weather has become a public health issue.

Even gig workers like Karuna Singh, who works as a beautician, has been forced to change her working hours to avoid the scorching afternoon sun. Before the summer set in, Singh would visit the homes of five to six customers a day, on average. But now she says that it’s become impossible to work in the afternoons as the heat peaks during that time, and she finds it tough to ride her electric scooter to visit customers.

“I begin work around 9am and try to head back home by 12 noon, and then schedule appointments only after 4pm when it’s slightly better to go out.” She adds that these days she barely gets two or three customers, and this has reduced her earnings to a great extent.

However, being the primary breadwinner in the family, the 39-year-old single mother of two young boys admits that it’s easier said than done. “There are some afternoons when I have no choice, but to go out in this stifling heat to earn a living.” Many times she has to ride for more than an hour for a session, and “that’s gruelling”.

Impact on labour productivity
According to NH Ravindranath, a former professor at the Indian Institute of Science, a climate change expert and an author on the United Nations’ Intergovernmental Panel on Climate Change (IPCC), scientists warned that billions of people will not be able to work outdoors due to severe heatwaves. He says this will have a major impact on labour productivity and lead to a loss of wages, especially in countries such as India.

India already loses around 101 billion working hours a year on account of heat, the most in the world, and risks seeing this number rise to 230 billion hours a year when global warming reaches 2 degrees Celsius over pre-industrial levels, according to a paper published in Nature in December 2021. That’s the equivalent of the work done by around 35 million people each working an eight-hour day, in a year.

At global warming of 2 degrees plus, the world will see the loss of 547 billion working hours due to heat, the paper, lead-authored by the Nicholas School of the Environment, Duke University, estimated.

“Many workers in the tropics are already stopping work in the afternoon because it’s too hot,” said Luke Parsons, a climate researcher at Duke’s Nicholas School of the Environment, who led the study.

“Luckily, about 30 per cent of this lost labour can still be recovered by moving it to the early morning. But with each additional degree of global warming, workers’ ability to adapt this way will swiftly decrease as even the coolest hours of the day quickly become too hot for continuous outdoor labour.”

Another ground-breaking report by the International Labour Organization (ILO) in July 2019 found that productivity loss due to heat stress – a build-up of body heat as conditions prevent people from cooling down – in India, brought on by rapidly rising temperatures, will be equivalent to the loss of 34 million full-time jobs in another 10 years.

Risk of heat stroke
Agriculture and construction work are expected to suffer the most, the ILO said. This is bad news for low-income workers employed in agriculture or construction, who are especially vulnerable to heat stress. In India, farming is the single largest occupation, followed closely by construction work, where people have to work for long hours outdoors in the sun and heat. The potential health consequences are heat exhaustion, heat stroke and sometimes death.

Meanwhile, public health experts state that no city in India reports daily all-cause mortality during summers, which they should.

During a panel discussion organised by the Natural Resources Defence Council (NRDC) on ‘Building Climate Resilience for the Most Heat Vulnerable: Strengthening Preparedness and Response in India’, Dr Dileep Mavlankar, said: “Like we report daily IMD forecasts, we should also report what is the total daily death toll of the day before.

“Along with mortality, what we also need to record are all-cause hospitalisation and ambulance pick-ups because these two data of a city are usually available on a daily basis and if we correlate [with heatwave period], we will see if we are seeing more hospitalisations during the heatwave.”

Restrict work during the hottest hours
Preventive measures that could be incorporated into public health policies include restricting work during the hottest hours, taking rest breaks, ensuring proper hydration and wearing appropriate work clothes, say experts.

According to a paper published by the country’s top meteorologists in 2021, heatwaves have claimed more than 17,000 lives in 50 years in India.

Meanwhile, the landmark Code Red report launched last August by the IPCC found that human-induced climate change is already affecting many weather and climate extremes in every region across the globe. The report by the UN’s body of climate experts found that averaged over the next 20 years, global temperature is expected to reach or exceed 1.5 degrees Celsius of heating.

The global average includes places like Antarctica and does not actually hold true all over India, where average temperatures have risen faster and higher. India will suffer more frequent and intense heatwaves, the IPCC report warned.

“Heatwaves and humid heat stress will be more intense and frequent during the 21st century,” the report said about South Asia, which includes India.

Arunabha Ghosh, CEO of the Council on Energy, Environment and Water, an independent policy and research institution in India, warned in a statement: “Given that India is one of the most climate-vulnerable countries, we must recognise that even geographically faraway climatic changes can have consequences for our monsoons and intensity of extreme events.

“Our focus should be on building climate-resilient physical and digital infrastructure along with inculcating social and behavioural changes in citizens and communities.”