HEATWAVES ARE BECOMING THE NEW NORMAL:WHAT DOES THAT MEAN FOR CITIES?

Abstract:
Heatwaves are no longer rare or occasional events they are becoming a regular part of life, especially in cities. With global temperatures rising due to climate change, many urban areas are experiencing longer, hotter, and more dangerous heatwaves than ever before. Cities are particularly at risk because of the urban heat island effect, where buildings, roads, and other concrete structures absorb and trap heat, making urban areas much warmer than nearby rural places. This article looks at how these intense heatwaves are affecting city life in different ways. It discusses how high temperatures can lead to serious health problems, especially for children, the elderly, and people with existing illnesses. It also explores how heatwaves put pressure on electricity and water systems, increase the risk of fires, and make air pollution worse. The article also highlights how cities are trying to adapt and protect their residents.
Solutions like planting more trees, creating green roofs, using reflective building materials, and developing heat action plans are being introduced in many places. However, the response needs to be faster and more inclusive, especially for poorer communities who are often the most affected. As climate change continues to make extreme heat more common, cities must take stronger action to reduce risks, protect vulnerable populations, and build a safer, cooler future for everyone.

Keywords: Heatwaves, Green Infrastructure, Public Health Impacts, Heat stress, Reflective surfaces, High-pressure systems.

Introduction:
In recent years the concerns related to heatwaves has increased drastically, which has resulted in affecting the life in the cities and causing health issues as well. In general a heatwave is a period of extremely hot weather that lasts for several days or more. It usually happens during the summer and is much hotter than what is normal for that place and time of year. In India, the India Meteorological Department (IMD) defines a heatwave in plain areas when the temperature is 40°C or more, and at least 4.5°C above normal in Hill areas when the temperature reaches 30°C or more and if the temperature reaches 45°C or more anywhere, it’s considered a severe heatwave, even if it’s normal for that time of year. The causes of these heatwaves are the climate changes, high pressure system, urbanization and loss of green cover. Cities are especially vulnerable due to the heatwave effect as cities are full of buildings, concrete roads which hold and absorb the heat much more than the natural land due which the cities have more effect of the heatwaves. Due to deforestation and urbanization the heatwave effect has increased, A heatwave is a period of extremely hot weather and it can cause serious problems for people’s health, daily life, and the environment. Cities like Delhi, Ahmedabad, and other parts of India have seen temperatures rise above 45°C, making it very hard for people to live and work safely. Heatwaves not only affect people’s health but also put pressure on electricity and water systems, reduce productivity, and increase the risk of fires
and pollution. People living in poorly built houses, slums, or working outdoors are especially at risk during these extreme heat events. As heatwaves become more frequent due to climate change, it is important to understand their impact and take steps to make our cities safer, healthier, and more prepared for the future.

Causes of Heatwaves:
The following are few major causes of heatwaves:

1. Climate Change:
   One of the biggest causes of heatwaves today is climate change. When we burn fossil fuels like coal, petrol, and diesel for energy, it releases harmful gases like carbon dioxide (CO2) into the air. These gases trap heat in the Earth’s atmosphere this is called the greenhouse effect. As a result, the planet is slowly getting warmer, and this makes heatwaves more frequent, longer, and hotter than before. Many scientists agree that the rising number of heatwaves around the world is a clear sign of climate change.
2. High-Pressure Weather Systems:
   Heatwaves are often caused by a high-pressure system in the atmosphere that stays over an area for several days. This system acts like a lid, trapping hot air near the ground and stopping cooler air, clouds, and rain from coming in. Because there’s no cloud cover or wind, the sun keeps heating the ground every day, and the heat builds up more and more. This leads to a long stretch of very hot days and warm nights which is exactly what we call a heatwave.
3. Urbanization (City Growth):
   As cities grow, more land is covered with buildings, concrete, and roads. These materials absorb heat during the day and release it slowly at night, making cities hotter than nearby villages or forests. This is known as the urban heat island effect. Also, cities usually have less green space, like trees and parks, which naturally cool the air. So, when a heatwave hits, cities feel much hotter and more uncomfortable than rural areas.

Impact of Heatwaves on Cities:

1. Health Problems:
   Heatwaves have a serious effect on human health, especially in cities where temperatures are even higher due to the urban heat island effect. Prolonged exposure to extreme heat can cause health issues such as heat exhaustion, dehydration, and in severe cases, heatstroke, which can be life-threatening. People with heart or breathing problems may find their conditions getting worse during a heatwave.
2. Hardships for the Poor and Outdoor Workers:
   The impact of heatwaves is felt most severely by poor communities and people who work outdoors. Many people living in slums or informal settlements do not have proper shelter, ventilation, or access to clean drinking water. Their homes are often made of tin or concrete,
   which traps heat, making indoor conditions unbearable.
3. Pressure on Electricity and Water Supply:
   During heatwaves, the demand for electricity increases sharply as people use fans, air coolers, and air conditioners to keep them cool. This high demand can overload the power supply systems and cause power cuts or blackouts, especially in older or poorly maintained grids. This puts pressure on the city’s water supply and can lead to water shortages, particularly in areas that already suffer from limited water access.
   

Mitigation Strategies Used by Cities:

1. Cool roofs and reflective surfaces:
   Here people paint their roof with reflective paint or coating to reflect sunlight and reduce indoor heat. Even whitewashing rooftops with lime or white paint in slum areas reduce indoor temperature by several °C. Example: Prayagraj’s rooftop whitewashing.
2. Green infrastructure:
   In green infrastructure, planting more trees which provide shade and cool the environment by absorbing heat or covering rooftops with vegetation or installing green walls helps reduce heat and the effects of heatwaves, resulting in a cooler environment.
3. Water-based / evaporative cooling solutions:
   In this method misting or sprinklers are used at public gathering areas or bus stops to reduce the effect of heat. Cities can utilize water bodies, fountains, and riverfront green spaces to help reduce heat. Example: Use of river or canal banks, or urban forest along rivers.
   Example: Mumbai’s Mithi River Urban Forest.
4. Better urban planning & building design:
   Passive cooling in buildings such as shade, ventilation, insulation, design also reduces direct solar exposure. New buildings should comply with building codes that mandate solar protection, including overhangs, window shading, and reflective surfaces.
5. According to National Disaster Management Authority (NDMA) Heat Wave
   Conditions can result in physiological strain, which could even result in death.
   To minimise the impact during the heat wave and to prevent serious ailment or death because of heat stroke, you can take the following measures:
    Avoid going out in the sun, especially between 12.00 noon and 3.00 p.m.
    Drink sufficient water as often as possible.
    Use fans, damp clothing and take bath in cold water frequently.
    Wear lightweight, light-coloured, loose, and porous cotton clothes. Use protective goggles, an umbrella/hat, shoes or chappals while going out in sun. Use ORS, homemade drinks like lassi, torani (rice water), lemon water, buttermilk,etc. which helps to rehydrate the body. Keep animals in the shade and give them plenty of water to drink. Keep your home cool, use curtains, shutters or sunshade and open windows at night. Avoid alcohol, tea, coffee and carbonated soft drinks, which dehydrate the body. Avoid high-protein food and do not eat stale food.

Conclusion:

Heatwaves are becoming a frequent and serious danger in cities, and their effects are now being felt in many areas from health to energy systems and daily comfort. Evidence shows that green infrastructure like parks, tree-lined streets, and green roofs can cool cities by several degrees, lower heat-related illness or deaths, and improve mental well-being. To protect people especially those most vulnerable, such as children, the elderly, outdoor
workers, and people in informal housing, cities need to act more urgently. Measures like planting trees of suitable species, using reflective building materials, improving ventilation in buildings, and making sure water and power systems are resilient are all important. Often the poorest neighbourhoods get least cooling benefit, but also suffer most during heatwaves.
Prioritizing those areas in planning and investment will help save lives and make cities more liveable for everyone. In short while climate change is making extreme heat more common, with coordinated action green design, better infrastructure, inclusive planning we can reduce the dangers, protect people, and build cooler, healthier cities for the future.

References

1.timesofindia.indiatimes.com

2. ndma.gov.in