6 Feb 2024 : Daily Answer Writing

Q1) Heat waves are a silent natural disaster. Describe the criteria for declaring heat waves and enumerate its humanitarian, environmental and economic impacts. (250 words/ 15 Marks)

ANS

A heat wave is a period of abnormally high temperatures, which in combination with high humidity may that leads to physiological stress in living beings.

Heat wave conditions are associated with maximum temperature of at least 40⁰C or more for plains, 37⁰C or more for coastal areas and at least 30⁰C or more for hilly regions:

1. Based on Departure from Normal Temperature:
   • Heat Wave: Departure from normal is 4.5°C to 6.4°C
   • Severe Heat Wave: Departure from normal is >6.4°C
2. Based on Actual Maximum Temperature:
   • Heat Wave: When actual maximum temperature ≥ 45°C
   • Severe Heat Wave: A heat wave is declared when the actual maximum temperature reaches ≥47°C and the preceding requirements are fulfilled in a minimum of two stations within a meteorological subdivision for a minimum of two days in a row.

The multifarious impacts of Heat waves can be seen as:

1. Environmental impacts:

• Heat waves can lead to water stress in floral and faunal species, and may also add to man animal conflict.
• Heat waves may further augment the arid conditions, creating situations of forest fires.

E.g., 2010 heat wave in Russia burnt almost 15 million hectares of forests.

• As per experts, heatwaves may also dry up shallow aquatic ecosystems and accelerate the melting of glaciers.

E.g., 2003 European heatwave resulted in a 10% loss in glacier mass in Europe.

• High energy demand may lead to an increase in carbon emission.

2. Economic impacts:
   • Heat waves result in enhanced fatigue and therefore leads to loss of productivity.

E.g., Globally, 2% of total working hours is projected to be lost every year.

1. • Heat wave strikes at the core of agrarian economic ecosystem of the country. E.g., In 2022, agricultural production in at least 9 states of India was subdued.
   • Increased demand for cooling will come at an additional cost to the troika of consumers, business enterprises, and the governments.
   • As per experts, heat waves can reduce the rural income by causing viral infection in crops and livestock.

E.g., pest in crops; reduced milk output.

3. Humanitarian impacts:
   • In Indian scenario, heat waves in combination with humidity may become a direct threat to human lives.

E.g., recent deaths (April, 2023) in Mumbai due to heat wave; around 350 million people were exposed to strong heat stress between April and May 2022, in India.

1. • Heat waves impact the vulnerable sections of the society the most.

E.g., daily wage labourers, food vendors, rickshaw pullers etc., are at heightened risk.

1. • Heat waves will negatively impact the social infrastructure.

E.g., loss of power supply in hospitals and schools due to high power demands.

There is a need to enhance climate literacy in order to mitigate the impacts of heat waves. To this end, the guidelines of NDMA about heat waves must be widely disseminated. Also, sustainable lifestyle, innovative measures such as Miyawaki forests, should be adopted to reverse the rising incidents of heat waves due to climate change.

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