HEATWAVES

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Context - The World Meteorological Organisation (WMO) stated that “Heatwaves are more frequent and more intense and starting earlier than in the past.”

 

Details

• As large parts of India experience rising temperatures, the World Meteorological Organisation (WMO) said that it is premature to make a conclusion that the extreme heat is only due to climate change.
• The WMO has also highlighted that now the Heatwaves are more frequent and more intense and starting earlier than in the past.
• The India Meteorological Department (IMD) said April was the hottest in northwest India in 122 years.

 

World Meteorological Organization

• The World Meteorological Organization (WMO) is a specialized agency of the United Nations (UN).
  • It is an intergovernmental organization within the UN System.
• It is responsible for promoting international cooperation in atmospheric science, climatology, hydrology and geophysics.
• The WMO is made up of 193 countries and territories and encourages the "free and unrestricted" exchange of data, information, and research between the respective meteorological and hydrological institutions of its members.
• It also collaborates with nongovernmental partners and other international organizations on matters related to environmental protection, climate change, resource management, and socioeconomic development.
• Its Headquartered is in Geneva, Switzerland.

 

About Heat Wave

• A heatwave or heatwave is a period of excessively hot weather, with high humidity, especially in oceanic climate areas.
• Heatwaves are usually measured relative to the usual weather in the area and relative to normal temperatures for the season.
• The definitions of heatwave vary from region to region. Temperatures that people from a hotter climate consider normal can be called a heatwave in a cooler area if they are outside the normal climate pattern for that area.
• Severe heatwaves have caused catastrophic crop failures, thousands of deaths from hyperthermia and widespread power outages due to increased use of air conditioning.
• A heatwave is considered extreme weather that can be a natural disaster and a danger because heat and sunlight may overheat the human body.
• Heatwaves can usually be detected using forecasting instruments so that a warning call can be issued.
• Climate models reveal that future heatwaves will have a more intense geographic pattern. The world will experience more intense, more frequent, and longer-lasting heat waves in the second half of the 21st century.
• Increased anthropogenic activities causing increased greenhouse gas emissions show that heatwaves will be more severe.
• Heatwaves and droughts, as a result, minimize ecosystem carbon uptake. Carbon uptake is also known as carbon sequestration. This will cause changes in the ecosystem's carbon cycle feedback because there will be less vegetation to hold the carbon from the atmosphere, which will only contribute more to atmospheric warming.

 

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, roadside 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 heatwaves such as dehydration, heat and sunstrokes.

 

Formation of Heatwave

• A heatwave occurs when a system of high atmospheric pressure moves into an area and lasts two or more days.
  • In such a high-pressure system, air from the upper levels of our atmosphere is pulled toward the ground, where it becomes compressed and increases in temperature.
• This high concentration of pressure makes it difficult for other weather systems to move into the area, which is why a heatwave can last for several days or weeks.
  • The longer the system stays in an area, the hotter the area becomes.
• The high-pressure system also prevents clouds from entering the region; sunlight can become punishing, heating up the system even more.
• The combination of all of these factors comes together to create the exceptionally hot temperatures we call a heatwave.
• This is common in summer (in both Northern and Southern Hemispheres) as the jet stream 'follows the sun'.

 

Heatwave in India

• In India, a region or locality is considered to be under the influence of a heatwave if the maximum temperature reaches or exceeds;
  • 40 degrees Celsius in the plains.
  • 30 degrees Celsius in hilly regions.
  • 37 degrees Over the coastal regions
• When the maximum temperature departure ranges between 4.5 and 6 degrees, the India Meteorological Department (IMD) declares a heatwave.
  • For example; If the normal temperature of a locality should be 40 degrees, and the actual recorded temperature is 45 degrees, the locality is under a heatwave.
  • A severe heatwave is declared when the recorded maximum temperature of a locality departure from normal is over 6.4 degrees.
• In India, heat waves occur from March to June, occasionally in July. The peak heatwave events have been reported in the month of May.
• As per the IMD, the most heatwave prone states are Punjab, Haryana, Delhi, Uttar Pradesh, Bihar, Jharkhand, West Bengal, Odisha, Madhya Pradesh, Rajasthan, Gujarat, Vidarbha, and parts of Karnataka, Andhra Pradesh, Telangana, and occasionally over Tamil Nadu and Kerala.

 

Why India is experiencing more heatwaves?

• 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 they are.
• Higher daily peak temperatures and longer, more intense heat waves are becoming increasingly frequent globally due to climate change.

Mitigation and Adaptation Strategies

• The Mitigation and Adaptation Strategies are intended to mobilize individuals and communities to help protect their neighbours, friends, relatives, and themselves against avoidable health problems during spells of very hot weather.
• The Government agencies need to play a critical role in preparing and responding to heatwaves at a local level, working closely with health and other related departments on a long term strategic plan.
• Establish Early Warning System and Inter-Agency Coordination to alert residents on predicted high and extreme temperatures. Who will do what, when, and how is made clear to individuals and units of key departments, especially for health.
• Capacity building/training programme for health care professionals at the local level to recognize and respond to heat-related illnesses, particularly during extreme heat events.
  • These training programmes should focus on medical officers, paramedical staff and community health staff so that they can effectively prevent and manage heat-related medical issues to reduce mortality and morbidity.
• Public Awareness and community outreach - Disseminating public awareness messages on how to protect against the extreme heatwave through print, electronic and social media and Information, Education and Communication materials such as pamphlets, posters and advertisements and Television Commercials on Do and Don’t and treatment measures for heat-related illnesses.
• Collaboration with non-government and civil society – a collaboration with non-governmental organizations and civil society organizations to improve bus stands, build temporary shelters, wherever necessary, improve water delivery systems in public areas and other innovative measures to tackle Heatwave conditions.
• 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 coordination, 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 are 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.
• Popularization 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 that the government can deploy in order to protect vulnerable groups.

 

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