Why most heat waves is seen this time in India?

• The impact of trapped air is heatwaves. Air usually circulates around the world in vast prevailing winds, but when it is stuck over one place, it is able to warm to unusual levels due to sunlight. Owing to high pressure systems, air is frequently caught.
• The air is forced downward by these systems, which operate as a big cap. Because the air is confined, it is unable to rise into the colder upper atmosphere and precipitation is prevented.
• As the sun moves north, the month of March is when the area ranging from Maharashtra to Odisha becomes a heat region, according to climatology.
• The warmer temperatures, according to reports, are due to the wind flow pattern in these places.
• Lower-level winds blow from the south to the north in these places, bringing hotter air from the land. The rising temperature is also aided by scorching breezes from India's desert region.
• The situation on Earth's poles is no different, with the climate catastrophe spreading and its impacts being felt not just in India but around the world.
• As the earth heats, both the Arctic and the Antarctic are feeling the heat. Scientists have warned that the already deteriorating climatic situation on the planet will deteriorate even faster and more abruptly.
• According to reports, record-breaking heat waves rocked Antarctica and the Arctic recently, with temperatures hitting 47°C and 30°C above average, respectively. Heatwaves are unusual in Antarctica at any time of year, but especially now, as the continent approaches winter darkness.
• Similarly, the Arctic is only awakening from its winter hibernation.

When India recorded highest heat waves?

• In 2022, India recorded its hottest March.
• This triggered an early onslaught of heat waves that engulfed several states across North, Central and East India from March-May this year, according to a new publication.
• Heat-wave like conditions prevailed in 16 states of India from March 11-April 24, 2022, stated State of India’s Environment In figures, 2022 .
• The country reported 280 heat wave days from March 11-May 18, 2022 — the highest in 12 years, it said. While IMD releases heatwave days for individual states every year, the book has added them up to reach the India figure. This has been done to make the numbers comparable.
•  For example: In 2011, heatwaves were reported in Andhra Pradesh (8), Rajasthan (7), Punjab (6), Haryana and Tamil Nadu (3 each), Madhya Pradesh, Odisha and Uttar Pradesh (2 each), and Bihar, Chhattisgarh, Delhi,  Gujarat, Jharkhand, Maharashtra and West Bengal (1 each). They add to 40 heatwave days for India.
• Heat waves on land and depressions in the sea this year began early in and around India on March 11, 2022.
• The country’s hazard atlas launched by the IMD in 2021 has not considered March while providing heat waves data.
• The IMD dashboard has provided figures on “heat waves” for the months of April to July only.  This is an indicator that “heat waves” in March, 2022 are “not normal”.
• This is almost double of what the country experienced in 2012, the second-highest heat wave year in the past decade.
• Heat wave is declared on the day an area records temperatures 4.5-6.4°C  above normal. When temperatures rise more than 6.4°C above normal, it is classified as a ‘severe’ heat wave.
• Five states accounted for 54 per cent of the heat waves this year. These were Rajasthan, Madhya Pradesh, Himachal Pradesh, Gujarat and Haryana, according to SoE in figures, 2022.
• Himachal Pradesh, Uttarakhand and Jammu & Kashmir — all in the Himalayan regions — have been unusually warm this year.
• HP recorded 27 heat wave days, Rajasthan 39 and Madhya Pradesh 38.

Situation in Antartica

• A stagnant, extremely intense pressure system stationed southeast of Australia caused the heatwave in Antarctica, transporting massive amounts of warm air and moisture down into the continent's interior. It was accompanied by a severe low pressure storm over the interior of East Antarctica.
• To make matters worse, cloud cover engulfed the Antarctic ice plateau, trapping heat from the surface. Because it's fall in Antarctica, the continent's core temperatures aren't warm enough to melt glaciers and the ice cover.
• However, the situation is said to be completely different on the coast, where rain has fallen, which is unusual for the continent.
• An atmospheric river - a narrow band of moisture accumulated from warm oceans – was chiefly responsible for the rain.
• Atmospheric rivers are found on the outskirts of low-pressure systems and have the ability to transport massive amounts of water over vast distances on scales larger than continents.
• Despite their uncommon, atmospheric rivers contribute significantly to the continent's ice sheets by dumping significant volumes of snow. Rain, rather than snow, occurs over Antarctica as surface temperatures reach above freezing.
• Air readings at the Australian Casey Station hit a maximum of -1.9°C in mid-March.
• They were more like mid-summer temperatures two days later, reaching a new March high of 5.6°C, which will evaporate ice.
• This is Casey Station's second heat wave in two years. Casey reached 9.2°C in February 2020, accompanied by a startling high of 18.3°C on the Antarctic Peninsula.

Where other than India this situation is experienced?

• India, along with Bangladesh and Pakistan, recorded the greatest losses to work hours (295 billion hours) due to heat exposure in 2020, according to the Lancet Countdown on Health and Climate Change released in 2021.
• India has become 15% more vulnerable to extremes of heat than in 1990.
• Indian senior citizens were among the most affected ones due to heatwave exposure.
• More recently, most parts of western Rajasthan, Maharashtra, and parts of Gujarat, Odisha are reeling under severe heat wave-like conditions, with maximum temperatures hovering well over 40℃.
• The foothills of the Western Himalayas recorded very high day and night temperatures - 7 to 10 degrees above normal.
• Delhi recently recorded a 36.6℃, 6 degrees above normal.
• The IMD’s long-term temperature trends indicate that the climate crisis is having a pronounced impact on increasing the frequency and severity of heatwaves in India.
• Average temperatures across seasons have seen a sharp upward trend in the country since 1991.
• The temperature rising trend is more evenly pronounced during monsoon (June to September) and post-monsoon (October to December) seasons.

Impact of Heat waves

• 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.
• Crop Damage: The fallout of these heat waves is far more complex - the concurrence of heat and drought events are causing crop production losses and tree mortality.
• 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.
• Labour Productivity Loss: A higher urban population also implies heat-induced labour productivity loss, resulting in economic impacts. Millions of farmers and construction workers could have lost income because on some days it’s just too hot for them to work.
• Wildfires and Droughts: The Lancet report, 2021 showed that populations of 134 countries experienced an increase in exposure to wildfires with droughts becoming more widespread than ever before.

Measures need to be taken

• Adopting A More Sensitive Approach: The impact of such excessive heat needs to be understood from the point of view of common people — daily labourers; farmers; traders; fishermen etc.
• Beyond numbers and graphs that capture the impact of the climate crisis, the human experience of living in oppressive heat needs to be understood by policymakers and measures should be taken accordingly.
• Cooling Shelters: The government should come out with a policy to deal with the suffering and disability caused by heat extremes in different parts of the country.
• Water kiosks, staggered outdoor work hours, cool roofs for buildings and homes are certain things that should be put in place immediately.
• A number of emergency cooling shelters can be opened so that people without domestic air conditioning units can escape the heat.
• Portable air-conditioning units, along with fans and even ice are also useful.
• Passive Cooling to Reduce Urban Heat Islands: Passive cooling technology, a widely-used strategy to create naturally ventilated buildings, can be a vital alternative to address the urban heat island for residential and commercial buildings.
• The IPCC report cites ancient Indian building designs that have used this technology, which could be adapted to modern facilities in the context of global warming.
• Action Plans Similar to Ahmedabad: As per the IPCC Report, Ahmedabad has shown the way to combat heat extremes by heat-proofing buildings.
• After the heat action plan was implemented in 2013 in Ahmedabad, heat-related mortality reduced by 30% to 40% over the years. Similar plans like that of Ahmedabad can be implemented in vulnerable regions.
• Replacing Dark Roofs: A big reason that cities are so much hotter than rural areas is that they are covered by dark roofs, roads and parking lots that absorb and retain heat.

Who termed Heat waves a ‘silent disaster’ ?

• Heatwaves are termed the “silent disaster” as heat-related deaths are often undercounted around the world for a number of reasons, wrote WWAN in its study.
• So, these are likely to be under-estimates as at least 39 deaths due to heat wave were reported from just 5 states — Maharashtra (26), Jharkhand (2), Odisha (6), Rajasthan (2) and Telangana(2) as of May 3, 2022.
• Climate change is rapid, widespread and irreversible, alerted Intergovernmental Panel on Climate Change (IPCC) in its sixth assessment report. The severity and frequency of extreme events will increase in a warming world, including India.
• Such events can make the elderly and residents of low-income areas more vulnerable, another study published in the journal Earth’s Future had noted.
• When extreme events including heat waves are set to increase in severity and frequency, the poor in informal housing, including the slum dwellers, will suffer the most.
• Affordable housing projects fail to comply with the latest energy code, according to a CSE analysis.
• This reminds of the urgency to incorporate heat-resilient, affordable housing as an integral element of “urban planning”.
• In 16 of the 56 cities analysed by SoE In figures, 2022, one out of every four residents lives in slums. These include three capital cities Raipur, Hyderabad , Mumbai.
• April was the hottest month for northwest and central India and the third-hottest April the country has seen in the past 122 years (1901 to 2022), IMD had analysed.
• Such unusual, early heat waves which swept India and Pakistan in 2022 were made 30 times more likely due to the direct impact of climate change, claimed a recent global study by World Weather Attribution Network (WWAN).
• These heat waves pose a major risk to public health and at least 90 deaths were recorded in the two countries (India and Pakistan), stated the global study based on media reports.

 Criteria for declaring Heat waves

• The India Meteorological Department (IMD) requires that temperatures should reach at least 40℃ in the plains and at least 30℃ in the hilly regions, and should reflect an increase of at least 5℃-6℃ above the normal temperature to be classified as a heatwave.
• The proximate causes for the searing heat are an absence of rain-bearing Western Disturbances or tropical storms that bring rain from the Mediterranean over north India.
• The combination of global warming and population growth in already-warm cities in India is the primary driver of increased heat exposure.
• The Urban Heat Island (UHI) also elevates temperatures within cities, which will be amplified during the heatwaves.
• It occurs when cities replace natural land cover with dense concentrations of pavement, buildings, and other surfaces that absorb and retain heat.

How Intense the Heat Waves have Become in India?

• Heatwaves are a common phenomenon in India during the months of May-June, however, heatwaves in the year 2022 began early due to the gradually increasing maximum temperatures in many parts of India.
• As per IMD, the number of heatwave days in India has increased from 413 over 1981-1990 to 600 over 2011-2020.
• This sharp rise in the number of heatwave days has resulted due to the increasing impact of climate change.
• The number of people killed due to heat waves has also increased from 5,457 over 1981-1990 to 11,555 over 2011-2020. Since 1967, 39,815 people have been killed due to heat waves across India.
• Based on the geo-climatic and socio-economic conditions, the highest number of people have been killed in Uttar Pradesh (6,745), followed by Andhra Pradesh (5,088), Bihar (3,364), Maharashtra (2,974), Punjab (2,720), Madhya Pradesh (2,607), West Bengal (2,570), Odisha (2,406), Gujarat (2,049), Rajasthan (1,951), Tamil Nadu (1,443), Haryana (1,116), Telangana (1,067), Delhi (996), Jharkhand (855), Karnataka (560), Assam (348), and 954 people were killed across the remaining 12 States.
• According to the Maharashtra Health Department, this year’s heat waves have claimed 25 lives in the State.
• According to a 2019 report of the Tata Centre for Development and the University of Chicago, by 2100, annually, more than 1.5 million people will be likely to die due to extreme heat caused by climate change.
• The increased heat will lead to an increase in diseases like diabetes, circulatory and respiratory conditions, as well as mental health challenges.
• According to an ILO report of 2019, India lost around 4.3% of working hours due to heat stress in 1995 and is expected to lose 5.8% of working hours in 2030.
• It also shows that 9.04% of working hours are expected to be lost in each agriculture and construction sectors, respectively, due to heat stress in 2030.

Way forward

• 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 is necessary.
• 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.