Scorching Reality: Can India Survive the Intensifying
Heatwaves?
Context
• A heatwave has led to 61 deaths from suspected heat stroke,
including 23 poll workers in the Lok Sabha election.
• Around 7 lakh people have been hospitalized in north India due to
extreme heat, with rising temperatures and no rain forecasted.
• Two weather stations in the capital New Delhi have reported
temperatures of 49 C (120.2 F) and 49.1 C (120.38 F) for Wednesday
29th May.
1. What are Heat Waves?
• Qualitatively- heat wave is a condition of air temperature which
becomes fatal to the human body when exposed.
• Quantitatively-it is defined based on the temperature thresholds over
a region in terms of actual temperature or its departure from normal.
• In certain countries it is defined in terms of the heat index based on
temperature and humidity or based on extreme percentile of the
temperatures.
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2. How are Heat waves defined in India?
In India IMD defines heatwave based on the following criteria.
Physiography of Condition
regions
• The maximum temperature recorded at a station
Plain is 40 degrees Celsius or more.
• The maximum temperature recorded at a station
Coast is 37 degrees Celsius or more.
• The maximum temperature recorded at a station
Hills is 30 degrees Celsius or more.
Based on Departure from Normal Temperature
• Heat Wave- Departure from normal is 4.5°C to 6.4°C
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• Severe Heat Wave- Departure from normal is >6.4°C
Based on Actual Maximum Temperature
• Heat Wave- When actual maximum temperature ≥ 45°C
• Severe Heat Wave- When actual maximum temperature ≥47°C
Heat Wave is declared if above criteria are met in at least 2 stations in
a Meteorological subdivision for at least two consecutive days.
3. Which are the heat wave prone states in India?
• Rajasthan, Punjab, Haryana, Chandigarh, Delhi, West Madhya
Pradesh, Uttar Pradesh, Chhattisgarh, Odisha, Vidarbha in
Maharashtra, parts of Gangetic West Bengal, coastal Andhra Pradesh,
and Telangana are the most heat-wave-prone states or regions.
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4. What is the status of Heatwaves in India?
• India has observed a significant mean temperature increase of 0.15
degrees C per decade since 1950, according to a 2020 assessment by
the Ministry of Earth Sciences.
• According to IMD, between 1981 and 1990 there were 413 heatwave
days in India.
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• The observed warming is not occurring evenly across India.
• Warm days and warm nights have also increased at about seven
and three days per decade, respectively, during the period 1951-
2015.
• Currently, 23 States, mainly of plain and coastal regions, are
considered more vulnerable to widespread heat impact.
• However, that doesn’t mean hilly states are safe. Although their
maximum temperatures do not reach heatwave threshold levels of 45
degrees C, the population is experiencing higher temperatures
compared to previous decades.
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5. What are Heatwave related Tolls in India?
• Nearly 25,000 people have suffered suspected heat stroke and 61 died
after several heat waves across India between March and
May,2024 as per the government data.
• When doing a comparison between the figures of 2000-2004 and 2017-
2021, The Lancet Countdown on Health and Climate Change:
Health at the mercy of fossil fuels, found that there has been a 55
percent increase in heat related deaths in India.
• India had reported 20,000 heat related deaths in adults over the age
of 65 annually in 2000 to 2004, and the number grew to about 31,000
deaths in 2017 to 2021.
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6. What are favorable conditions for Heat wave?
Condition Analysis
Transportation / • There should be a region of warm dry air and
Prevalence of hot appropriate flow pattern for transporting hot
dry air over a air over the region.
region
Absence of • As the presence of moisture restricts the
moisture in the temperature rise.
upper
atmosphere
The sky should • To allow maximum insulation over the
be practically region.
cloudless
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7. How does the India Meteorological Department
(IMD) monitor the Heat wave?
• IMD has a big network of surface observatories covering the entire
country to measure various meteorological parameters like
Temperature, Relative humidity, pressure, wind speed & direction
etc.
• Based on daily maximum temperature station data, climatology of
maximum temperature is prepared for the period 1981-2010 to
find out the normal maximum temperature of the day for a
particular station.
• Thereafter, IMD declared a heat wave over the region as per its
definition.
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8. What is impact based heat wave warning issue by
India Meteorological Department (IMD)?
• India Meteorological Department issues following color code
impact based heat warning jointly with the National Disaster
Management Authority.
9. What is the status of Heatwaves in other Countries?
United States
• Heat Wave Characteristics in the United States by Decade, 1961–2021.
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Europe:
• Number of occurrences of heat waves in Europe from 1995 to 2015.
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10. What are the factors behind the increase in
Heatwaves in India?
• There are multiple reasons why heat waves occur in India, and they are
primarily caused by a combination of meteorological, geographical,
and human factors.
• Some of the significant contributors to heat waves in India include:
Factor Description
Meteorologica • Heat waves in India can be caused by
l Factors: meteorological factors include high-pressure
systems over northwestern India, the Arabian
Sea, and the Bay of Bengal.
• This creates a stagnant air mass that traps hot and
dry air, leading to higher temperatures.
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• The climate can also be affected by the El Niño
Southern Oscillation (ENSO) and the Indian
Ocean Dipole (IOD), which can contribute to the
occurrence of heat waves.
Geographical • India's position near the equator results in high
Factors: levels of solar radiation all year round, especially
during the summer season.
• The country's terrain, which includes deserts, semi-
arid areas, and high-altitude regions, can also
worsen the conditions of heat waves.
Human • Human activities like urbanization, deforestation,
Factors: and poverty can increase temperatures and create
heat island effects, making vulnerable populations
more susceptible to heat-related illnesses due to the
lack of access to cooling and drinking water, and
inadequate public health infrastructure.
• “Urbanization alone has led to an overall 60%
enhancement in warming in Indian cities,” as per
the study published in the journal Nature stated.
Urban heat • The Intergovernmental Panel on Climate
island Change (IPCC) Working Group-II, which assesses
impacts of, and vulnerabilities to climate change,
has noted that the urban heat island effect leads to
cities experiencing air temperatures that are several
degrees warmer than surrounding areas, especially
during the night, “reducing adaptive capacity”.
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11. What are the effects of Heatwaves?
Effects Description
Health • Heatwaves can have significant impacts on health,
depending on the timing, intensity, and duration of
high temperatures.
• Exposure to excessive heat can lead to various
illnesses, including heat cramps, heat exhaustion,
heatstroke, and hyperthermia.
Economy • A 2020 McKinsey Global Institute paper estimated
that “an increase in lost labour hours due to rising
heat and humidity could put approximately 2.5-4.5
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per cent of GDP at risk by 2030, equivalent to
roughly $150-250 billion.”
Labour • According to an ILO study at 34°C, workers can lose
Productivity up to 50% of their work capacity.
Social • Heat waves can have social impacts, such as
Impacts increased crime rates, social unrest, and
migration.
• Populations that are vulnerable are at a higher risk of
being affected.
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Environmen • Extreme heat can increase the risk of other disasters
tal Impact: like droughts and wildfires.
• They can also lead to the spread of disease-carrying
insects, such as mosquitoes and ticks.
Effects on • On hot days air quality can worsen due to ground-
Air Quality level ozone production and pollution from air
conditioning.
Decreases • High temperatures resulted in moisture stress,
Agriculture sunburn, flower drop and less fruit setting in
Output: horticultural crops such as kinnow, pomegranate,
mango and lemon.
• Similarly, in the case of vegetables, significant impact
was observed especially in tomato, cole crops and
cucurbits.
• The heat wave coincided with grain filling and
development stage of wheat, yellowing and
shriveling of grain, forced maturity, resulting in
reduction of yields up to 15-25%.
Power • Heatwaves can cause power breakdowns due to
Breakdown: excessive usage of air conditioners, leading to high
electricity consumption and outages.
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12. What are the initiatives taken by the government to
address the issue of heatwaves?
Policy/Initiatives Description
National • Provides a framework for heatwave mitigation
Disaster under disaster management, including early
Management warnings, capacity building, and inter-agency
Plan (NDMP) coordination.
National Action • Addresses adaptation under its “National
Plan on Climate Mission on Sustainable Agriculture” including
Change managing heat stress on crops/livestock.
(NAPCC)
National Action • It aims to facilitate capacity building,
Plan on Human surveillance, preparedness and awareness
Health and generation for climate-sensitive health risks,
Climate Change including heat stress.
Heat Action • City-level plans were initiated after the
Plans Ahmedabad model to issue early heatwave
warnings, minimize exposure of at-risk groups
and boost health system preparedness.
National • Mandates development of disaster-specific
Disaster action plans, including for heatwaves, outlining
Management prevention, preparedness and risk reduction.
Policy
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13. What You Can Do to Reduce impact of Heatwaves?
Increase shade • Planting trees and other vegetation lowers
around your home surface and air temperatures by providing
shade and cooling through evapotranspiration.
• Trees and vegetation that directly shade your
home can decrease the need for air
conditioning, making your home more
comfortable and reducing your energy bill.
Install green roofs • A green roof, or rooftop garden, is a
vegetative layer grown on a rooftop.
• Green roofs provide shade and remove heat
from the air through evapotranspiration,
reducing temperatures of the roof surface and
the surrounding air.
Use energy- • Using efficient appliances and equipment in
efficient appliances your home can help to lighten the load on
and equipment the electric grid during heat waves, thus
ensuring a more reliable supply of electricity
to your community.
• Replacing your old appliances and equipment
with ENERGY STAR-qualified products can
also help save you money.
14. What are the measures one should take to minimize
the impact during the heat wave?
• Avoid going out in the sun, especially between 12.00 noon and 3.00
p.m.
• Drink sufficient water and as often as possible, even if not thirsty
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• Wear lightweight, light-coloured, loose, and porous cotton clothes. Use
protective goggles, umbrella/hat, shoes or chappals while going out in
sun.
• Avoid strenuous activities when the outside temperature is high. Avoid
working outside between 12 noon and 3 p.m.
• While travelling, carry water with you.
• Avoid alcohol, tea, coffee and carbonated soft drinks, which
dehydrates the body.
• Avoid high-protein food and do not eat stale food.
• If you work outside, use a hat or an umbrella and also use a damp cloth
on your head, neck, face and limbs
• Do not leave children or pets in parked vehicles
• If you feel faint or ill, see a doctor immediately.
• Use ORS, homemade drinks like lassi, torani (rice water), lemon water,
buttermilk,etc. which helps to rehydrate the body
15. What can be possible way forward:
1. Urban greening
• Urban greening – creating living walls, roofs and green corridors –
can benefit cities in areas of high rainfall, including around the equator.
• The World Economic Forum’s Global Commission on
BiodiverCities and Adrienne Arsht-Rockefeller Foundation
Resilience Center (Arsht-Rock) have developed the Heat Action
Platform, an online resource that provides cities around the world with
a roadmap and tools to address extreme heat.
2. Appointing Chief Heat Officers
• Jane Gilbert became the world’s first Chief Heat Officer in May
2021, and as global temperatures rise it’s becoming an increasingly
widespread and important role.
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3. Passive cooling
• A US study found strategies like shading and natural ventilation
could reduce pressure on air conditioning by up to 80%.
16. What is the relevance of the topic for UPSC CSE?
For Prelims:Heat Waves, Indian Meteorological Department (IMD),
global warming, urban heat island effect, El Nino , Sendai Framework
for Disaster Risk Reduction 2015-30, Nature-based solutions,
Intergovernmental Panel on Climate Change (IPCC), Passive cooling
technology.
For Mains: Role of India Meteorological Department (IMD) in
mitigating severe weather events, Concept of the Heat Index.
Some previous years prelims questions.
Q1. What are the possible limitations of India in mitigating global
warming at present and in the immediate future? (2010)
1. Appropriate alternate technologies are not sufficiently
available.
2. India cannot invest huge funds in research and development.
3. Many developed countries have already set up their polluting
industries in India.
Which of the statements given above is/are correct?
(a) 1 and 2 only
(b) 2 only
(c) 1 and 3 only
(d) 1, 2 and 3
Ans: (a)
Some previous years mains questions.
Q1. Bring out the causes for the formation of heat islands in the urban
habitat of the world. (2013)
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Some questions from this year and previous years
interview transcripts.
Board Dinesh Dasa sir(2024)
• Difference between CDRI and NDMA ?
Board Suman Sharma mam(2024)
• What are man made disasters?
• What to do as dm?
• Major changes in NDMA after 2005?
Board Sanjay Verma sir(2024)
• Global warming is going to affect both MP and Kerala in a similar way.
• Analyze it for me.
Board Lt. Gen Raj Shukla sir(2023)
• What is a heat wave ?
• What steps should we take to deal with heat waves ?
Board BB Vyas sir(2023)
• Your optional is geography, why are we facing so high temperatures
and heat waves, etc (talked about the IPCC report )
• What is the solution for this?
• What are marine heat waves?
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Some questions for QUIZ.
Q1. Consider the following statements regarding Heat Waves
1. It heat waves should be declared when actual maximum
temperature remains 45°C or more.
2. Heat Waves often occur when high-pressure systems stall
over a region.
3. High temperature and High humidity, referred to as the wet
bulb temperature makes heat waves deadly.
How many of the above statements are incorrect?
Select the correct answer using the code given below:
(a) Only one
(b) Only two
(c) All three
(d) None
Ans: (d)
Some questions for POLL.
Q1. Have you ever suffered from heat waves ?
(a) YES
(b) NO
(c) Can’t say.
Q2. Has the frequency of Heat waves increased in the last decade?
(a) YES
(b) NO
(c) Can’t say.
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