Heat Wave

Heat Wave

Subject: Environment

Context- Deadly heatwave building across India, Pakistan: Experts

Concept-

• A deadly heatwave is building across India and Pakistan, A new an lysis by climate scientists has directly connected the heatwave with climate.
• New Delhi could touch 44-45°C, approaching its record April temperature, while some parts of North India could touch 46°C.
• Heatwave warnings have been issued, with public health experts pointing out that extreme heat so early in the year is particularly dangerous.

What are Heat Waves?

• A heat wave is a period of abnormally high temperatures, more than the normal maximum temperature that occurs during the summer season in the North-Western and South Central parts of India.
• It is a condition of air temperature which becomes fatal to the human body when exposed.
• The IMD declares a heatwave when the maximum temperature crosses a certain threshold — 40°C in the plains, 37°C along the coast, and 30°C in hilly regions.
• Alternatively, a heatwave is declared if the maximum temperature rises by between 5°C and 6.4°C above normal.
• A severe heatwave is declared when the maximum temperature rises more than 6.4°C above normal.
• A third condition for a heatwave arises when an area records a maximum temperature of more than 45°C and up to 47°C on any given day.

What is the Impact of these Heat Waves?

• Crop Damage:
  • The concurrence of heat and drought events is causing crop production losses and tree mortality.
  • India has already suffered the hottest March in 122 years of weather data, and parts of the country are seeing wheat yields drop 10-15 per cent partly due to the unseasonal heat.
• Less Food Production and High Prices:
  • The risks to health and food production will be made more severe from the sudden food production losses exacerbated by heat-induced labour productivity losses.
  • These interacting impacts will increase food prices, reduce household incomes, and lead to malnutrition and climate-related deaths, especially in tropical regions.
• Mortality and Morbidity: The Intergovernmental Panel on Climate Change (IPCC) in the Second Part of AR6 Report flagged that heat extremes are causing human deaths and morbidity.
  • The increased heat will lead to an increase in diseases like diabetes, circulatory and respiratory conditions, as well as mental health challenges.
• Labour Productivity Loss:
  • A higher urban population also implies heat-induced labour productivity loss, resulting in economic impacts.
• Wildfires and Droughts:
  • The Lancet report showed that populations of 134 countries experienced an increase in exposure to wildfires with droughts becoming more widespread than ever before.