Heat Waves: Notes for UPSC General Studies

A heatwave is a period of extremely hot weather, accompanied by high humidity from time to time, especially in oceanic climate countries.

The topic of Heat Waves and their risks are featured in the General Studies section of the UPSC Prelims Exam.

Aspirants would find this article very helpful while preparing for the IAS Exam. 

Definition of Heat Waves

The World Meteorological Organization defines a heatwave as five or more consecutive days during which the daily maximum temperature exceeds the average maximum temperature by five degrees Celsius. For detailed information on WMO – World Meteorological Organisation visit the linked page.

• If the maximum temperature of the affected region continues to be more than 45° C consecutively for two days, it will be declared a heatwave-affected area. 
• The heatwave is also called a “silent disaster” as it occurs at a slow pace, but still inflicts large-scale casualties on humans and animals alike.
• In India, heat waves typically occur between March and June, and on rare occasions, in July.
• Heatwaves frequently occur in Northern India, especially in the Gangetic-belt regions.

To know the location of the World Meteorological Organizations and other important organisations of the world, visit the linked article.

Favourable conditions for Heatwave

• Air that is hot and dry is frequently present over a region.
• The upper atmosphere is free of moisture.
• There should be almost no clouds in the sky.
• Anticyclonic flow with a large amplitude over the region.

Origin of heat waves

• Heat waves are formed for one of two reasons: because warmer air is flowing in from elsewhere or because something is producing it locally. 
• Air is warmed locally when the air is warmed by higher land surface temperature or because the air sinking down from above is compressed along the way, producing hot air near the surface.

Causes of Rising Heat across Northwest India

• Climate change: Any abnormal or extreme weather events are attributed to climate change these days. In most cases, particularly those related to unusually high temperatures, climate change and heat waves are interrelated and are indeed the aggravating factor.
• Anticyclonic formation: An anticyclonic formation over south Gujarat is one of the main reasons for the warming on the west coast. Its effect was transmitted northward to Rajasthan, Punjab, Delhi, Himachal Pradesh, and western Uttar Pradesh. There are anticyclones developing over north India as well as the Iran-Afghanistan-Pakistan-Tibet belt causing hot and dry weather. 
• Absence of Western Disturbances: Inactive western disturbances frequently cause rainfall deficits in plains and hilly regions, which are reflected in higher temperatures, resulting in a heat wave. The current hot spell (2023) is due to the lack of western disturbance activity in February, which brings some rain and keeps temperatures down.
• Climatic conditions during summer months: The dusty, hot and dry winds blow over the northwestern region and the Indo-Gangetic Plains during summer months making these regions vulnerable to frequent heat waves.  
• Absence of La Nina Event: Globally, 2023 is widely expected to be a little hotter than the previous two years, mainly because of the expected end of the strongest-ever La Niña event. The absence of La Niña conditions could impact weather leading to substantially warmer temperatures.

Effect of Heat Waves

• On Agriculture: The high temperatures can harm wheat crops as they approach the reproductive growth period, which is temperature sensitive. There are fears that the early “soaring temperature above normal” in North India will cause some anxiety among the country’s farmers.
• On food and public health: A strong cold chain network will be necessary for India’s long-term food security and public health security. A single temperature drop during the journey can disrupt the cold chain, spoiling fresh produce and reducing vaccine potency.
• On Indian Economy: The rising heat across India can jeopardize economic productivity. India showed the largest heat exposure impact on heavy labour among South Asian countries.

Impact of Heat Waves

• Civic troubles:
  • HAPs use information-dissemination strategies to inform the public, but without reliable vulnerability and risk assessments, it is uncertain if these efforts can effectively reach the most vulnerable people, especially in large cities and states with high populations.
  • There is a need to link actions in agriculture, water, housing, infrastructure, and urban design to existing policies to maximise capacity and finances.
• Crisis in the farm and food sector:
  • Extreme temperatures could lead to a shortage of raw materials due to crop failure.
  • And such a situation could lead to supply chain disruption and higher inflation.
  • Higher temperatures would adversely impact the shelf life of vegetables, fruits and dairy products.
  • Way forward:
    • By investing in technologies like advanced forecasting models, cold storage, and temperature-controlled transportation, it’s possible to ensure a consistent supply of raw materials and finished products.
• Demand for electricity:
  • In April, the peak power demand reached a historic high of 215 GW.
    • Peak power demand is the highest amount of power required at a specific point in time.
  • In terms of consumption, the same day recorded the peak energy demand.
    • This indicates that there has been an increase in electricity usage in the country.
• Other issues:
  • The extreme heat and subsequent atmospheric conditions can cause physiological stress, leading to fatalities and adversely impacting those residing in these areas.
  • More than 90% of the country is facing an extreme level of risk that can negatively affect different aspects of life.
    • This includes the ability to adapt livelihood, the yield of food grains, the spread of vector-borne diseases, and urban sustainability.
  • Heatwaves triggered by climate change in India are causing immense strain on public health, agriculture, and various socio-economic and cultural systems.
  • These effects have the potential to impede or undo the progress the country has made towards achieving sustainable development goals.

How can risks from Heat Waves be reduced?

With the help of the following methods, the problems caused by heat waves can be reduced

• Early warning system and inter-agency coordination –Temperature forecasts and heat alerts must be sent as bulk messages on mobile phones not just by the nodal agency in charge but also by the other relief agencies as well.
• Medical up-gradation and administrative measures –Heat treatment wings must be created in hospitals, and an advisory on how to prevent exposure and other heatwave related injuries must circulate in schools and offices
• Public Awareness and community outreach – Raising public awareness messages on how to protect against extreme heat-wave situations must be done through electronic, print as well as social media, and IEC materials.
• Collaboration with NGOs and civil society organizations – Building temporary shelters, wherever necessary, improving water delivery systems in public areas and other innovative measures to tackle heatwave conditions must be implemented
• Assessing the impact –Feedback for reviewing and updating the plan for heatwave disaster risk reduction must be made a regular feature in Government actions as this can help in preparing early prevention plans in accordance with the developing situation.

Ways to address the health effects of heat:

• A person suffering from heat needs to be shifted to a cool place under the shade
• Cool the person by keeping a cool wet cloth on the body
• Provide a rehydrating drink
• Loosen clothes for better ventilation

Another consequence of a heatwave is the Urban Island Heat effect. To know how both go hand-in-hand with each other, visit the linked article.

Candidates can check the relevant links for the preparation of upcoming UPSC Examination-

Advisory by the National Disaster Management Authority of India

The National Disaster Management Authority of India (NDMA) has issued an advisory on what those in a heatwave affected area should do and not. They are as follows:

Do’s

• Drink enough water and whenever possible, even if not thirsty. It is necessary to stay hydrated in these conditions.
• Schedule strenuous jobs to cooler times of the day.
• Increasing the frequency and length of rest breaks when involved in outdoor activities.
• Pregnant workers and workers with a medical condition should be given additional attention and leave if necessary.
• Planting trees and or even smaller plants will reduce the surface and air temperatures by providing shade and cooling around your house.

Don’ts

• Do not leave children or pets in parked vehicles. The metallic bodies of these vehicles will super heat the vehicles resulting in dehydration and at times even death.
• Avoid going out in the afternoons, especially around 12.00 noon and 3.00 p.m.
• Do not wear dark, heavy or tight clothing. Wearing loose clothing is advisable has it allows the body to exhale more easily
• Do not engage in physically demanding activities when the outside temperature is high.
• Do not cook during peak hours. But should you choose to, open doors and windows to ventilate the cooking area adequately?
•  Drinks like tea, alcohol, coffee and aerated drinks, will dehydrate your body faster. So they must be avoided
• Avoid food items high in proteins and completely avoid eating stale food.

Heat Waves – UPSC Notes:- Download PDF Here

The above details would help candidates prepare for UPSC 2023.

UPSC exam-related preparation materials will be found through the links given below.

Aspirants can find complete information about upcoming Government Exams through the linked article.