India's outdoor labourers struggle to cope as country faces new reality of extreme heat waves

As the fierce midday sun beat down on his 2.4 hectaresof fields in India's northern Uttar Pradesh state, Ali Sher shrugged and carried on sorting through the cucumbers he's cultivated, telling his wife and seven children to keep going.

"We work here the whole day," the 53-year old farmer told CBC News. "No matter how hot it gets, we still have to work. We have no other option."

The intense heat also scorches the crops forcing the family to spend more time outside, watering and tending to the cucumbers, which they cart into large barrels, fastening them to sell later at a local market.

"If we don't work [in the heat], then what will we do?" Sher said.

He and other outdoor labourers are among the most vulnerable as India, a country highly exposed to the effects of increasing heat, grapples with the new reality. The number of hot days is rising, and experts predict Indian heat waves will start earlier, last longer and become more frequent, as the effects of climate change are felt on the subcontinent.

The IndiaMeteorological Department released a report in April that stated the length of heat waves had grown by three days over the last 30 yearsbut that they were projected to increase by 12 to 18 daysover the next 30 or 40 years.

Last year was the fifth hottest on record, according to India's weather monitoring agency, which officially attributed 30 deaths to a declared heat wave even though experts believe that's an underestimation, with many mortalities linked to the weather not being recorded.

As temperatures hovered around the low 40s C in Modinagar, Uttar Pradesh, the vendors at a busy local market struggled to find any possible shade under tattered umbrellas, with some opting for damp scarves around their heads.

"What can we do to save ourselves from the heat?" saidDinesh, 30, who, like many Indians, goes by only one name, as he sold his okra and cucumbers. "There are no facilities around."

'Killer' combination of heat and humidity

The risks are not only health-based.

India where much of the population works outside with little protection from the elements suffers from more heat-related labour losses than any other country in the world, and it's poised to get worse by the end of this decade.

The International Labour Organization projects India will lose six per cent of working hours because of extremely warm weather, the equivalent of 34 million full-time jobs.

"It has an impact on agricultural productivity, it has an impact on manual labour, it has an impact on our economy in general," said Chandra Bhushan, the CEO of the International Forum for Environment, Sustainability &Technology (iFOREST), a non-profit focused on climate research based in New Delhi.

"People think that a heat wave is only about temperature. But I think the killer is a combination of heat and humidity," Bhushan said.

"That's what wet bulb temperature is all about. And in India, the wet bulb temperature is increasing, which means that outdoor activity will reduce."

The threat, which can be deadly, comes when the outdoor wet bulb temperature which is the lowest temperature at which air can be cooled by evaporation inches higher. When it's extremely hot, human sweat evaporates and cools the body down, but when humidity levels are too high and the air is filled with so much moisture already, that sweat can't evaporate to cool body temperatures.

WATCH | Can India handle more extreme heat?:

India tries to adapt to the threat of extreme heat

1 year ago

Duration 2:02

There's a push to adapt to extreme heat in India as heat waves get more intense, and scientists expect it to get worse over the next few decades.

And the threshold at which wet bulb temperature readings are dangerous is much lower than traditional temperatures. If intense heat and humidity combine to push the wet bulb temperature past 32 C, it makes being outside doing physical activity extremely difficult.

"The problem is that climate change is simultaneously increasing temperature and humidity," Bhushan said, adding that the rise in the intensity of heat waves is not unique to India.

Deadly event a 'wake-up call'

It was that deadly combination of high heat and humidity that fuelled an April heat wave that swept across South Asia, causing 13 deaths at a large outdoor event outside of Mumbai, where thousands of attendees were sitting under the blazing sun for several hours.

Hundreds of others were hospitalized after suffering from heat stroke symptoms, and subsequent outdoor events in Maharashtra state were hastily cancelled.

The heat wave was made at least 30 times more likely due to climate change, a group of international climate scientists concluded in a study done by the World Weather Attribution initiative.

"I think it's been a huge wake-up call because of the kind of publicity it got," said Debi Goenka, an environmentalist and the executive trustee ofthe Mumbai-based Conservation Action Trust, referring to the high number of deaths at the outdoor event.

"Even though the incident was very unfortunate, it has actually woken up a lot of people to start taking heat precautions."

It also prompted India's weather authorities to experiment with modifying how it declares a heat wave, taking into account not just the heat, but also the humidity. The new heat index code is expected to be ready in the coming months.

A push to adapt

The country is trying to adapt, with a sprawling heat action plan that's been in place since 2013. But with so many regions dealing with different hot weather effects, it's local governments that need to take charge,Bhushansaid.

"Most action has to happen at the city level, the local level."

There are companies working at the grassroots level on initiatives that focus on small steps aiming to make a big difference.

At a government-run daycare centre in one of Chennai's poorest neighbourhoods, in India's southern Tamil Nadu state, Savitha Narayanamurthy held a temperature gun in her hand, taking numerous measurements as she wove around the dozen children playing loudly in the centre of the room.

Above her, the rooftop of the small building now has a budding garden, planted only two weeks earlier.

"We're noticing around a one degree difference, between one and 1.5[degrees cooler]," she told CBC News, only a few days after she started measuring the temperature.

Narayanamurthy is working here for cBalance, a Mumbai-based sustainability consultancy that is focused on low-cost and low-tech solutions particularly geared towardIndia's poor, who often live in cramped urban settlements that provide little escape from crippling heat waves.

Its other projects include installing aluminum foil cooling slabs on the rooftops of individual homes in Mumbai's slums, which reflect the sun back and keep the heat out of the building. The firm isalso experimenting with setting out water-filled PET recyclable plastic bottles in a rooftop grid, to try to trap the heat from going inside and affecting the indoor temperature.

Meanwhile, the company is anxious for the rooftop garden at the Chennai daycare to grow rapidly over the next few months.

"As the green patch increases, we look forward to the temperature difference being somewhere around threedegrees to what it is usually," Narayanamurthy said, as she took a cloth to wipe the sweat from her brow.

"So the children can feel a little cooler sitting inside where they are playing," she said, adding it's already encouraging to see even the smallest effect.

"We feel hopeful about it."