India and Pakistan had terrible effects from the recent 2022 heatwaves in March and April. At least 90 deaths are thought to have resulted from it in India and Pakistan.
Heat waves have multiple, interconnected effects on the economy, environment, agriculture, energy, and water.
The heating effect decreased Punjab’s and Uttar Pradesh’s wheat harvest production. Nowadays, heat waves are occurring more frequently and are becoming stronger and longer-lasting due to climate change.
What is Heatwave?
A heat wave is a rise in air temperature that, if experienced by humans, is fatal.
It is a stretch of unusually hot weather with temperatures that are higher than average and often last three days or longer.
Heatwaves typically occur in India between March and June. May is the peak month of the heat wave over India. Every season, on average, two to three heatwave events are anticipated.
In India, central and northwest, as well as the coastal states of Andhra Pradesh and Odisha, report heatwaves frequently which occur due to favorable atmospheric conditions.
Criteria for Declaring Heatwave
In order to be considered a heat wave, a station’s highest temperature must be at least 40 degrees Celsius for plains regions and 30 degrees Celsius for hilly regions.
a) Based on Departure from Normal
Heat Wave: Departure from normal is 4.5 degrees C to 6.4 degrees C
Severe Heat Wave: Departure from normal is >6.4 degrees C
b) Based on the Actual Maximum Temperature
Heat Wave: When the actual maximum temperature is≥ 45 degrees C
Severe Heat Wave: When the actual maximum temperature ≥47 degrees C
Declaring Heat Wave for coastal stations
Heat Waves may be defined when the maximum temperature deviates by at least 4.5 degrees Celsius from the average, providing the maximum temperature actually experienced is at least 37 degrees Celsius.
What are favorable conditions for Heatwaves?
There are certain conditions that favor the occurrence of heat waves. A few important ones are-
Transportation / Prevalence of hot dry air over a region: For the purpose of distributing hot air over the area, there should be a region of warm, dry air and a suitable flow pattern.
Absence of moisture in the upper atmosphere: Moisture prevents temperatures from rising.
The sky should be practically cloudless: To allow the area to be as well-insulated as possible.
Large amplitude anti-cyclonic flow over the area: Heat waves typically originate over Northwest India and move progressively south and east, but not west (since the prevailing winds during the season are westerly to northwesterly).
Impact of Heatwave
Heatwaves impact all aspects including the environment, health, economy, etc.
Environmental and Societal Impact: According to studies conducted throughout the years, India is seeing more heatwave days on average every decade. The average length of heat waves has increased over the past 30 years by around three days, and by 2060, a further increase of 12 to 18 days is anticipated.
It is expected that with time, heat waves will eventually expand to other regions, including the southern regions of India.
A condition known as “wet bulb” temperature, which at its mildest can cause considerable discomfort and at its worst can result in dehydration and death, is on the rise in some parts of eastern India, including Andhra Pradesh, Telangana, and Odisha.
According to a study by researchers at IMD, In India, heat waves have claimed the lives of more than 17,000 people over the past 50 years.
Impact on Health: The health impacts of Heat Waves majorly involve dehydration, heat cramps, heat exhaustion, heat stroke, etc.
There is a significant increase in stress, anxiety, and sadness during a heatwave, which could cause or aggravate mental, behavioral, and cognitive disorders.
Cost of Living: Extreme temperature-related health effects and diseases could result in high medical expenditure. These make a household’s monthly spending plan even worse.
Energy: On average, electricity costs for a household in an urban area climb by 15% to 20% during heat waves.
Reasons for the Occurrence of Heatwaves in India
Heatwaves are caused by large-scale atmospheric circulation anomalies like high-pressure areas, upper-tropospheric, jet streams, etc.
The frequency and length of heat waves in India are also modulated by global factors, such as the El Nino/Southern Oscillation (ENSO) and the Indian Ocean.
The heat wave is also significantly attributed to climate change. An abnormal change in the temperature or the weather is referred to as climate change. This threat is caused by the over usage of gases, coal, and oil products.
Local factors like reduced soil moisture and increased sensible heat flux might aggravate the consequences of the heatwave.
Measures Taken to Tackle Heatwave
India now has a robust national framework for heat action plans that involve the India Meteorological Department (IMD), national and state disaster management authorities, and local organizations. The core of this heat action plan is the early warning system.
The Ministry of Earth Sciences (MoES) had set up an improved forecast system for early heatwave warnings as part of the National Monsoon Mission. IMD has the ability to predict heatwave occurrences’ origin, duration, and intensity up to four or five days in advance with a degree of reasonable accuracy.
For the first time, researchers from IMD, IITM, and MoES have shown that Indian heatwaves may be forecast even one season in advance.
A multi-model ensemble (MME) should be used for seasonal forecasts. The soil moisture network forecasting method developed by IMD and microwave satellites should be used for short-range ensemble forecasts, together with higher-resolution global models initialized with observed soil moisture data.
Building local health care providers’ abilities to identify and treat illnesses brought on by excessive heat. To successfully prevent and manage heat-related medical conditions and lower mortality and morbidity, these training programs should focus on medical officers, paramedical workers, and community health professionals.
Public awareness and community outreach – Using print, electronic, and social media, as well as information, education, and communication (IEC) materials like pamphlets, posters, and advertisements, as well as television commercials (TVCs) on dos and don’ts and treatment options for heat-related illnesses, public awareness messages on how to protect against the extreme heat wave, are being transmitted.
Collaboration with non-governmental and civil society organizations. To combat heatwave conditions, non-governmental and civil society organizations have worked together to improve bus stops, construct temporary shelters where necessary, and implement better water delivery systems in public spaces.
Through the use of reflective materials and processes, Cool Roofs reduce heat absorption and enhance the building’s overall thermal comfort.
Article Written By: Priti Raj