Cause and Effect | Delhi's scorching heatwaves call for urgent heat action plans

How is a heatwave classified?

The India Meteorological Department defines heatwaves differently, based on different geographic regions.

In the plains, a heatwave is characterised by maximum temperatures reaching up to 40°C or more, while in coastal areas, it is when maximum temperatures reach 37°C or higher and the deviation from normal is between 4.5 and 6.4°C above the average maximum. In hilly regions, the threshold is set at 30°C or higher. If these conditions persist for two consecutive days, a heat wave is declared on the second day.

If these conditions persist for two consecutive days, a heatwave is declared on the second day. Heatwave conditions in India are typically experienced between March and July, with acute spells occurring mostly between April to June.

IMD in April this year forecast that most of India is in for a searing summer between April and June, as it warned of “extreme heat” and more than double the number of heatwave days than is seen usually at this time of the year.

And the forecast has largely held true: 14 of 36 subdivisions in the country have recorded over 15 heatwave days between March 1 and June 9, IMD data has shown.

With rising temperatures, there is also a greater focus on the impacts of these heatwaves, particularly for communities vulnerable to weather extremes because of limited means.

While Delhi is yet to record a death due to heatstroke, nearly 200 people have died of heat-related symptoms in the country. The increasing fatalities have brought heat action plans back into the debate, arguably, a bit late.

What are heat action plans?

The heat action plan is a policy document prepared to effectively understand and respond to a heat wave. These are prepared by authorities at various levels and serve as a comprehensive guide, outlining measures to prepare for, respond to, recover from and learn from extreme heat events.

The primary purpose of these plans is to protect vulnerable populations and direct essential resources, including healthcare, financial support, information, and infrastructure, to those most at risk during a heatwave.

The National Disaster Management Authority directs that a heat action plan must provide a framework for implementation, inter-agency coordination and impact evaluation; alert those at high risk; mobilise departments and communities; and establish early warning systems; among other things.

A searing heatwave in Gujarat in 2010, which claimed over 1,000 lives in Ahmedabad in a week, prompted the city to devise a plan to avoid similar devastation again.

Ahmedabad: A success story

The pioneering Ahmedabad heat action plan was implemented in 2013, introducing multi-level coordination, a three-tier warning system, and an overall year-round scaling up of infra.

The Ahmedabad Municipal Corporation partnered with the Indian Institute of Public Health-Gandhinagar (IIPH-G) and the US Natural Resources Defense Council (NRDC) to develop India’s first heat action plan. An estimated 1,190 deaths have been avoided each year since its launch in 2013.

Following the blueprint of the Ahmedabad HAP, more than 100 cities in India have started to work on similar plans or even introduced them in some cities.

The Delhi heat action plan was implemented in April this year, but the impact on the ground will likely become apparent at a later stage.

The Delhi plan, in limbo

According to the latest document, Delhi’s HAP is to be implemented in three phases.

Phase I (the pre-heat season of February and March): Focus on capacity building, developing early warning systems and a communication plan for issuing alerts to the public, healthcare professionals, and voluntary groups. Civic agencies are required to build shelters, sheds and bus stands with cool roofs. The labour department is required to ensure changes in the shifts of outdoor workers, while the transport department and the Delhi Jal Board (DJB) are listed as the agencies that will provide adequate drinking water across the city.

Phase II (the heat season of March to July): Requires the labour department to ensure outdoor workers do not work in the peak hours of 1-5 pm, non-essential water use is suspended and the education department has to ensure that "schools do not function during peak hours (12 noon to 4 pm)" when a heatwave is declared. “Cooling centres” such as temples, public buildings and malls have to be activated to provide adequate shade and the MCD is required to provide stray animals adequate water and shelter.

Phase III (the post-heat season of July to September): Requires establishing cool resting centres and carrying out tree plantation in heat hotspots.

Looking beyond the documents

The success of a heat action plan depends on three things: a dedicated resource officer, for the plan to be regulated and proper financing, said Abhiyant Tiwari, Lead - Climate Resilience and Health, NRDC India.

“The Ahmedabad plan worked well because there was a dedicated department for its implementation. Within the city health department, there was a nodal officer who was the chief heat officer,” Tiwari, who was also instrumental in devising the 2013 plan, told HT.

“Secondly, all such plans so far are only on advisory levels. The state, or the city or the district it is being implemented in does not have a mandate to follow the directives of the plan. This is because heat is not a notified disaster like for example cyclones. The two disasters are inherently different, a heatwave is slow-onset and covers a much larger geographical area. However, cyclones are notified as a natural disaster by the NDMA. Hence, the response to it is mandatory. But the same isn’t true for heatwaves,” Tiwari explained.

The last thing to ensure proper implementation of a heat action plan, Tiwari said, is funding. “Apart from ownership, cities must account for heat action plans in their annual budgets. If there is an allocated budget, the administration will have to show its work, the infrastructural development; basically, give proof of how that budget was spent.”

The challenges

The WMO in its Global Annual to Decadal Climate Update report on June 5 said that the world is going to cross the 1.5°C threshold in the next five years. In such a scenario, the people not only need to mitigate, but interventions in the form of adaptations are equally necessary.

The heat action plans, thus, advise measures like building cool roofs in vulnerable areas: an aspect of the Ahmedabad heat action plan that has found resonance across the world.

“Obviously when temperatures reach 45-46°C, ACs are the optimal solution. However, they are not ideal as one cannot install an AC everywhere. They are expensive, so the people who need them the most may not be able to afford them. And they end up adding to the heat. Hence, passive cooling options like cool roofs come into play,” Tiwari said.

Nothing and no one is immune from the heat, he said. And when stress from persistent heat rises, the impact can be felt across sectors, including the health sector.

“Not only will we need to train health care providers in how to recognize and treat heat stress, we will also need to scale up physical infrastructure. It's basic demand and supply. When more people suffering from heat-related illnesses arrive at hospitals, there will be a higher need for equipment. Or the quality of care will decline,” he said.

An additional burden is the need for continuous power supply, in both residential and medical sectors.

He added that so far the heat action plans have failed in adequately assessing the vulnerable groups across geographies, classes, genders and age groups.

Meanwhile, heatwaves are set to get more intense in coming years.

In an April 22 interview to HT, Friederike Otto, Senior Lecturer in Climate Science at Grantham Institute - Climate Change and the Environment, Imperial College London warned: “With millions of people living in poverty and extremely hot summers, heat is a massive challenge for India. Heatwaves are the deadliest type of extreme weather there is. They’re often referred to as silent killers. In India, our study found that human-caused climate change made heatwaves at least 30 times more likely and at least 2°C hotter. Similar heatwaves with temperatures well above 40°C will become hotter and hotter in India as the climate warms, so India needs to prepare.”

Tannu Jain, HT's deputy chief content producer, picks a piece of climate news from around the globe and analyses its impact using connected reports, research and expert speak