Delhi Is Boiling Near 50℃, And The Country Is Crossing The Expected Peak Power Demand: How Is The ‘Urban Heat Island’ Contributing To Rising Temperatures In Cities And What Can Be The Probable Solutions?

India’s peak power consumption reached a record 246.1 GW by 03:00 p.m. Wednesday, as the country’s northwest and central regions continue to suffer from extreme hot conditions. Power demand crossed the government’s expected peak of 235 GW for solar hours in May. The power ministry had anticipated peak power demand at 235 GW this month in the daytime and 225 GW in the evening hours.

Regarding the national capital, as of 5:30 p.m. on Wednesday, Delhi registered its highest-ever peak of 8,302 MW. It exceeded the expected peak demand of up to 8,200 MW this summer. In May, peak electricity consumption in Delhi exceeded 7000 MW for 12 days in a row, the first time this calendar year. On May 22, the city’s peak electricity consumption reached 8,000 megawatts (MW).

With New Delhi sweltering at nearly 50℃, the notion of global warming has never been more genuine. Of course, north India is no stranger to scorching temperatures in the run-up to the monsoon rains. According to a Tata Power Delhi Distribution Ltd representative, the ongoing heat wave in northern India is causing a substantial increase in energy consumption in the national capital. According to analysts, the jump in power demand is mostly due to the hot weather, which causes people to use air conditioners and coolers more frequently, increasing electricity usage.

A decade earlier, when we used to talk about heat waves, the ‘Global warming’ discussion took our attention. After that, just last year, when July 2023 was announced as the hottest month ever recorded, we entered the era of ‘Global Boiling’. And now, when deep studies are done, it emerged that a notion called ‘urban heat island’ is increasing, contributing to an increasingly hot climate. So, what are the factors that are causing heat stress across the nation?

High humidity and Rising concretisation: The underlying factors causing excessive heat stress in Delhi and other megacities.

According to a recent analysis from the Centre for Science and Environment (CSE), India’s megacities are facing higher heat stress as a result of rising concretisation and humidity levels, and they are not cooling down at night as rapidly as they did ten years ago. From January 2001 to April 2024, the CSE analysed data on summer air temperature, land surface temperature, and relative humidity in six megacities: Delhi, Mumbai, Kolkata, Hyderabad, Bengaluru, and Chennai.

The study found that megacities do not cool down at night. During the summers of 2001-2010, the land surface temperature dropped by 6.20-13.20 degrees Celsius between the midday high and the midnight low. The CSE reported that night-time cooling has dropped to 6.20-11.50 degrees Celsius over the previous ten summers (2014-2023), resulting in hot evenings that are just as harmful as noon high temperatures.

Why is high heat + high humidity problematic for life?

Now if you feel high heat, you will sweat and hence feel better. This is how the body’s mechanism works to tackle the surrounding heat. However, with high humidity, this effect of sweating is taken for a ride, and the human body struggles to deal with the heat trapped inside the body.

Evaporation of perspiration from the skin cools our bodies, but greater humidity levels reduce this natural cooling. As a result, people can develop heat stress and sickness, which can be lethal even at considerably lower ambient temperatures. Moreover, people have limited time to recover from the midday heat if temperatures stay high overnight.

Not only human health but higher humidity has troubled seasonal cycles as well, delaying the monsoons.

The think tank discovered that higher humidity exacerbates heat stress across all climatic zones, even cancelling out the small decline in air temperatures in Delhi and Hyderabad. Except for Bengaluru, the other five megacities’ midsummer average relative humidity increased by 5-10% between 2014 and 2023 when compared to the 2001-2010 average. According to the study, increased humidity levels have rendered monsoons in Delhi, Mumbai, Kolkata, and Chennai hotter than during pre-monsoon months. 

Rising concretisation: The concept of Urban Heat Island?

It was observed that all megacities have become increasingly concrete in the previous two decades, increasing heat stress. The CSE said that increasing green cover does not effectively reduce evening heat. The study attributes it to the “urban heat island” effect, in which densely populated places trap heat, limit green cover, increase traffic congestion, absorb heat, and generate more heat from human activity. This effect makes city centres significantly warmer, particularly at night. 

Every year, Delhi endures tremendous heat. Prior to the 2024 records of 8302 MW, the highest recorded value was 7695 MW on June 29, 2022. In 2023, the highest electricity consumption was 7438 megawatts. 

According to a new study from the Indian Institute of Technology Bhubaneswar, urbanisation has resulted in approximately 60% higher nighttime warming in over 140 significant Indian cities than in non-urban areas surrounding them. According to the study, Ahmedabad, Jaipur, and Rajkot had the most urban effect, while Delhi-NCR and Pune ranked fourth and fifth, respectively. Urbanisation is known to cause the urban heat island (UHI) effect, in which concrete and asphalt surfaces (used in road and pavement construction) absorb heat during the day and release it in the evening, elevating nighttime temperatures.

The study aimed to evaluate how much urbanisation and local climate change contributed to rising nighttime temperatures during the last two decades (2003-2020). “The average urban effect for all of these cities in India was 0.2 degrees Celsius per decade. This leads to an estimate that urbanisation is responsible for 37.73% of overall urban warming, or approximately 60% more warming than the surrounding non-urban areas,” researchers explained.

They also discovered that cities in the northwest, northeastern, and southern areas had a “more significant increase” in nighttime temperatures than the rest of the country. However, the researchers found that urbanisation contributed more to night-time warming in eastern and central Indian cities, which are emerging and expanding rapidly.

Almost all of the cities included in the study had rising night-time surface temperatures, which climbed by roughly 0.53 degrees Celsius on average every decade. Furthermore, the trend of greater nighttime temperatures was not restricted to cities, as most of India warmed by 0.26 degrees Celsius on average per decade throughout the study period, the researchers reported. This showed that cities were warming at about twice the pace of the rest of the country.

The authors highlighted that because cities are especially sensitive to the collective effects of urbanisation and climate change, the people and infrastructure in these places are on the “frontlines” of climate change consequences, including heat waves, extreme weather events, and flooding.

According to the WRI (World Resources Institute) India Ross Centre, by 2050, seven out of every ten people on the planet will live in cities. While the Global South is predicted to account for almost 90% of growth, India will account for a sizable portion of it, the report stated. According to the WRI India Ross Centre, 36% of India’s population, or around 40 crore, lives in cities, which will double to 80 crore by 2050.

The study emphasised the necessity for a variety of mitigation actions to successfully reduce continued urban warming. With India anticipated to be the world’s fastest-expanding economy and the highest urban expansion, the latest results may assist urban planners and politicians in better-allocating resources and comprehending the scale of planning necessary to develop sustainable cities.

How human efforts to keep themselves cool have resulted in more hotter temperatures?

The effect of urbanisation is not only with concrete and asphalt roads, but glass buildings and air conditioners are contributing comparatively to the degree of ‘Urban Heat island’.

Researchers have identified another factor that is exacerbating the previously existent difficulties of heatwaves: Western architecture.

India is positioned near the equator and has significantly greater temperatures than most western countries. Traditional vernacular architecture was well-suited to the Indian environment, but by the 1990s, it was gradually losing favour. In the 1990s, India was moving to a market-based economy; liberalisation and globalisation policies enticed western firms to establish operations in India owing to cost savings. As a result, when new offices were erected, international corporations adopted the same style as they had in the West.

Tall buildings with glass doors and reflecting facades have become commonplace in major Indian towns. It would be difficult to discern between the cityscapes of Bangalore, Delhi, and Mumbai. Blindly adhering to the one-size-fits-all design approach has resulted in more serious challenges than merely unattractive looks. Tall buildings require a sturdy structure, and builders often utilise concrete and steel constructions. Despite being sturdy construction materials, they retain a lot of heat. The glassy facades reflect heat, increasing the warmth of the surroundings.

According to Chandra Bhushan, an environmental policy specialist based in Delhi, 90% of construction projects use modern Western-style design with little regard for regional climate and vernacular architecture. Architects and their staff construct what they see; therefore, we only see lookalikes. Hence, these tall buildings with glasses everywhere reflect not only India’s growth story but also reflect heat to nearby surroundings, hence contributing towards making the area into ‘Urban Heat Island’.

So, is it only concrete roads and tall glass buildings that are helping in ‘Urban Heat Island’? No, there is one more reason. The great Air Conditioners, aka our ACs. how does the AC trap cool us by heating the surroundings?

Most of us choose to disregard the ironic fact that using air conditioners to be cool has a direct correlation with global warming. Not only can more people afford air conditioners, but more countries (including India) can supply the increased demand for power. According to one research, the number of air conditioners will reach 4.5 billion by 2050, which is excellent news for appliance manufacturers but bad news for the environment, as the resulting greenhouse emissions will cause a 0.5-degree Celsius spike in world temperatures.

Wow, so we are cooling ourselves by emitting heat to our surroundings, which will gain heat for us, and again, we will use AC to cool Ourselves! Note the awful irony of this loop: hotter temperatures lead to more AC; more AC leads to hotter temperatures.

So, is there only a problem, and no solution can be reached?

Global warming, global boiling, urban heat island, climate change, everything is connected. Solving the individual problem will not help in getting rid of these heat waves. A chain of collective solutions, taking into account every individual problem in simultaneous steps, may result in fruitful results.

Need 1: Mindful management in city planning by the government.

The trapping of heat caused by a dense concentration of buildings paved roads, and other surfaces composed of materials such as concrete, glass, and steel results in greater temperatures in cities than in outlying places. Trees, bushes, grass, and soil absorb heat and cool the ground; but, because they are increasingly lacking in Indian urban planning, and what remains is being destroyed, what remains is concrete and asphalt, which absorb and increase the day’s heat, remaining hot for several hours at night. 

Last year, Earth Sciences Minister Kiren Rijiju informed the Lok Sabha that the Indian Meteorological Department (IMD), in partnership with the National Disaster Management Authority (NDMA) and local health departments, had launched Heat Action Plans (HAPs) in various regions of the nation. While more than 20 states have collaborated with the NDMA to develop HAPs, the majority remain on paper. They are impeded by a lack of funds, granularity, and a long-term strategy for transformation. Experts increasingly think that city-specific management strategies that consider local conditions are a considerably more effective response to heat waves.

Such plans should promote green spaces and water bodies while targeting all heat sources, such as automobiles, industry, and concrete surfaces — one example is Ahmedabad’s Cool Roofs initiative, which provides an inexpensive solution to the urban heat island effect. Long-term planning, in addition to emergency measures taken during a heat event, can protect cities from overheating and save lives.

Need 2: Mindful construction of homes.

Earlier houses were made using clay or sun-dried bricks, which are poor heat conductors. Houses have spacious courtyards with windows to allow for cross ventilation and heat dissipation. Roofs were covered in thatch to dramatically limit heat transfer. Today, it is hard to fully adapt to the architectural methods of 50 years ago. The cost of land has risen, and some amenities have become the norm and irreplaceable. Still, the way forward is to apply vernacular architecture lessons to current methods. 

As British architect Laurie Baker, widely known as the Gandhi of architecture, stated, “true meaning of architecture lies in the responsible and prudent use of limited resources and imbibing the characteristics that surround it”.

He emphasised avoiding excess and grandeur in designing. He stated that it is the architect’s responsibility to study and investigate the site, determine its benefits and weaknesses, and use the resources available in an effective manner. The onus is now on the new generation of architects to revive vernacular architecture and adapt it to present and future contexts.

Many novel methods are being investigated, such as double walling, which has two concrete walls separated by an insulating substance such as clay or sand. Limewash is being employed to whitewash terraces and rooftops to reflect heat from outside. Green terraces and window gardening are gradually becoming regular practices. Instead of closed chambers, designs should be made so that verandas and cross-ventilation methods can be practised.

Need 3: The conscious attempts by human beings to comfort themselves. 

There is no doubt that human comfort is something that could never be compromised. However, conscious efforts are needed from the citizens’ end to contribute ion tackling the heatwaves. Rooftop plants are such an alternative to reduce the temperature to a certain extent. 

If you think this is very uncommon or hard, read this amazing story of a rickshaw driver in New Delhi who installed a garden on the vehicle’s roof – planted with more than 20 types of plants. Yellow and green auto rickshaws are common on New Delhi’s roadways, but Mahendra Kumar’s vehicle is anything but ordinary. Kumar claims that the dense area of flora prevents heat from entering the vehicle, thus keeping his passengers cool while they travel about the Indian capital.

This keeps the phrase going: ‘Necessity is the mother of invention’. If such a person, who may or may not be skilled enough to calculate the rising degrees and understand the terrible effect of Celsius boiling, then we, literate citizens, can obviously figure out ways to cool ourselves without damaging or less damaging to the surroundings.

It is time to shift direction, and the urban landscape may improve during the next 7 to 8 years.