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Heat Wave

Topics Covered:

  1. Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc., geographical features and their location- changes in critical geographical features.
  2. Disaster and disaster management.

 

Heat Wave

 

What to study?

  • For Prelims: What are heat waves and how are they classified?
  • For Mains: Why is India vulnerable, effects of heatwaves on health, environment and economy, how should India be prepared?

 

Context: The National Disaster Management Authority (NDMA) is conducting a two-day national workshop on heat wave risk reduction on 27-28 February, 2019.

This workshop aims to sensitise the States to the need of preparing and implementing specific Heat Action Plans. Some of the most vulnerable States, which have done a commendable job in mitigating the impact of heat waves, will share their experiences and best practices to help other stakeholders draw lessons.

 

India’s concerns:

The Lancet Countdown 2018 report has asked the Indian policy makers to take a series of initiatives to mitigate the increased risks to health, and the loss of labour hours due to a surge in exposure to heatwave events in the country over the 2012-2016 period.

 

Why is India more vulnerable?

  1. From 2014-2017, the average length of heatwaves in India ranged from 3-4 days compared to the global average of 0.8-1.8 days, and Indians were exposed to almost 60 million heatwave exposure events in 2016, a jump of about 40 million from 2012.
  2. A recent report has placed India amongst the countries who most experience high social and economic costs from climate change. Overall, across sectors India lost almost 75,000 million hours of labour in 2017, from about 43,000 million hours in 2000.
  3. The agriculture sector was more vulnerable compared to the industrial and service sectors because workers there were more likely to be exposed to heat.
  4. The India Meteorological Department had reported that from 1901 to 2007, there was an increase of more than 0.5°C in mean temperature, with considerable geographic variation, and climate forecasts by research groups project a 2.2-5.5°C rise in temperatures in northern, central and western India by the end of the 21st century.

 

What is a heatwave?

Heat wave is considered if maximum temperature of a station reaches at least 40°C or more for Plains, 37°C or more for coastal stations and at least 30°C or more for Hilly regions.

 

Following criteria are used to declare heat wave:

  1. Based on Departure from Normal:
  • Heat Wave: Departure from normal is 4.5°C to 6.4°C.
  • Severe Heat Wave: Departure from normal is >6.4°C.

 

  1. Based on Actual Maximum Temperature (for plains only):
  • Heat Wave: When actual maximum temperature ≥ 45°C.
  • Severe Heat Wave: When actual maximum temperature ≥47°C.

To declare heat wave, the above criteria should be met at least in 2 stations in a Meteorological sub-division for at least two consecutive days and it will be declared on the second day.

 

Health Impacts of Heat Waves:

  • The health impacts of Heat Waves typically involve dehydration, heat cramps, heat exhaustion and/or heat stroke.
  • Children, the elderly and those with pre-existing morbidities are particularly vulnerable.
  • Vegetable vendors, cab drivers, construction workers, police personnel, road side kiosk operators and mostly weaker sections of the society have to work in the extreme heat to make their ends meet and are extremely vulnerable to the adverse impacts of heat waves such as dehydration, heat and sun strokes.

 

Reasons why India is experiencing more heat waves are:

  • Magnified effect of paved and concrete surfaces in urban areas and a lack of tree cover.
  • Urban heat island effects can make ambient temperatures feel 3 to 4 degrees more than what they are.
  • More heat waves were expected as globally temperatures had risen by an average 0.8 degrees in the past 100 years. Night-time temperatures are rising too.
  • Higher daily peak temperatures and longer, more intense heat waves are becomingly increasingly frequent globally due to climate change.
  • High intensity of UV rays in medium-high heat wave zone.
  • Combination of exceptional heat stress and a predominantly rural population makes India vulnerable to heat waves.

 

Way ahead for India- How India should deal with heat waves?

  • Identifying heat hot-spots through appropriate tracking of meteorological data and promoting timely development and implementation of local Heat Action Plans with strategic inter-agency co-ordination, and a response which targets the most vulnerable groups.
  • Review of existing occupational health standards, labour laws and sectoral regulations for worker safety in relation to climatic conditions.
  • Policy intervention and coordination across three sectors health, water and power is necessary.
  • Expedite the rollout of the National Action Plan on Climate Change and Health.
  • Preventing temperature-related morbidity and mortality could be a key programme under this mission.
  • Ensure an adequate supply of water. Timely access to drinking water can help mitigate this escalation.
  • Further research using sub-district level data to provide separate indices for urban and rural areas to enable more targeted geographical interventions.
  • Provision of public messaging(radio, TV), mobile phone-based text messages, automated phone calls and alerts.
  • Promotion of traditional adaptation practices, such as staying indoors and wearing comfortable clothes.
  • Popularisation of simple design features such as shaded windows, underground water storage tanks and insulating housing materials.
  • Advance implementation of local Heat Action Plans, plus effective inter-agency coordination is a vital response which the government can deploy in order to protect vulnerable groups.

 

Mains Question: Examine the adverse impacts caused by heat waves and how India should deal with it?