Ranjan Kumar Padmapati
(The writer can be reached at rkpadmapati@yahoo.co.in)
The months of April, May, and June—these three months are considered to be summer months in India. As of now, people are experiencing extreme heat-wave events in different parts of the country. The World Meteorological Organisation states that the upcoming EI Nino effects, combined with heat-trapping greenhouse gases, will result in global temperatures rising between 2023 and 2027, above pre-industrial times by 1.5 degrees. Recently, a national daily carried a report that the city of Kolkata has recorded a high of 43 degrees Celsius, the highest April temperature in the last seven decades. In Gangetic West Bengal, Kalai Kunda recorded a temperature of 47.2 degrees centigrade on April 30, 2024. The temperature was already in the range of 43–46 degrees centigrade in most of the places in Odisha, Telangana, Andhra Pradesh, and Gangetic West Bengal. Temperatures are 5-7 degrees above the normal range. The Indian Meteorological Department has released a note that the South Peninsula average mean temperature has reached 31 degrees centigrade in April, which is the 2nd highest temperature so far since 1901, and in East and NE states in April, it is 28.1 degrees centigrade, the highest in the same period since 1901. It is reported that between 2021 and 2050, the temperature is expected to rise by 2–3.5 degrees in 100 districts and 1.5–2 degrees in 455 districts.
A heatwave is defined as when a maximum temperature at a place records more than 45 degrees centigrade in plains, 37 degrees in coastal areas, and 30 degrees in hills. And also, when the temperature exceeds 4.5–6.4 degrees centigrade above the maximum normal temperature, the severity of the heatwave could be known from the following death records: in 1998–3058; in 2015–204; and in 2022, it was 2227. In 2023, on average, 2 people died due to heat waves during April, May, and June. In fact, 952 people had died by June 2023. It has been reported that 2023 was the hottest year in the last 122 years. The relative humidity plays an important role, known as the humidity index, which increases the heat severity with the index. At an even moderate temperature of 35 degrees Celsius with a relative humidity of 70%, people will feel a situation corresponding to 50 degrees Celsius. In 2023, Guwahati recorded the highest temperature of 38.9 degrees, but it was unbearably hot for the high humidity index.
Heatstroke is the result of a heatwave in individuals after not being able to regulate or balance the body temperature in their surroundings. It is more prevalent among children, elderly people, and pregnant women. The normal human body maintains a body temperature of 36.3–37.3 degrees centigrade. The body maintains the heat balance by transferring heat through the skin through 40% radiation, 30% evaporation, 27% convection, and 3% conduction. Any internal or external condition that will increase body temperature invokes psychological responses, changing cardiovascular, kidney, and metabolic systems, and increasing blood flow. Cities bear the brunt of heatwaves more because of a peculiar phenomenon known as heat islands. City temperatures remain at an elevated level compared to the surrounding villages even at night because of the more built-up concrete areas that absorb heat and the fact that there is less grass and forest cover to cool down. This could be illustrated by giving the example that the temperature at Six Mile in Guwahati was found to be higher by 5 degrees centigrade than that of the Amchang area. Bengaluru is experiencing a high of 38 degrees Celsius; people started installing air conditioners in a city where even fans were unseen earlier. The built-up area of Bengaluru has now increased by 1055% in the last fifty years, as revealed by the Indian Institute of Sciences; the city is now 93% concrete jungle. The situation is not different in other cities, either. Roof-top gardens and an increase in forest cover will give some respite. Severe heatwave events are being triggered more by climate change, increasing ambient temperatures, and other environmental degradation, with the root cause being the emission of huge amounts of greenhouse gases. It is to be noted that the carbon-dioxide level reached 425 ppm in 2023. It is 30 times more likely that the last April 2023 heatwave in India was the result of climate change. Fossil fuel-fired power generation must be switched over to green power.
Common people like construction workers, auto and cab drivers, rickshaw pullers, vegetable vendors, police personnel, and roadside vendors are more vulnerable to heatwaves causing sunstrokes and heat stress. Sunburn is associated with skin redness, swelling, fever, blisters, headaches; Heat Cramps with painful spasms in legs; Heat Exhaustion is recognized by heavy sweating, weakness, a weak pulse, fainting, and vomiting; Heat Strokes induce high body temperature; hot, dry skin; rapid, strong pulse, sweating, etc. are some common symptoms. Such persons should be immediately shifted to a cool place or a/c room and given sips of water, the application of a cool wet cloth, or a sponge to reduce body temperature. Medical attention is an urgent requirement. General tips to avoid such situations are to drink sufficient water and fruit juice to stop dehydration, avoid the hot sun between noon and 3 pm, use porous cotton, loose garments for proper ventilation, umbrellas, caps, carry water bottles, lemon water, curd, ORS, water-soaked rice as food, etc., which will give temporary relief. Strenuous physical activities under the hot sun are to be avoided. Hospital PHCs are to be augmented to meet such emergencies; potable water distribution points at vulnerable places are to be made available.
Assam being a power-deficient state, power requirements are met mostly by outsourcing. This requires a special mention, as demand for power increases sharply during the summer. The pattern of the south-west monsoon has been altered drastically due to climate change. The dry spell months in Assam extended beyond August, even up to September in 2023, due to fewer monsoon rains. In Assam, peak hour power demand increased to 2500 MW from 1800 MW abruptly, but it received only 1650 MW from different sources in 2023. According to APDCL, on September 4, 2023, the demand was 2540.42 MW, surpassing the previous record of 2534.54 MW on August 17, 2023. Assam experienced a shortfall of 600–900 MW on a daily basis during the summer of last year. August 2023 temperatures were closely 1.5 degrees Celsius warmer than the average temperature from 1850 to 1900, a threshold limit set by the Paris Agreement. On an all-India basis, in April 2024, power consumption already rose by 11% to 144.25 billion units, compared to 130.08 billion units in April 2023. Assam’s power purchase agreement requires a quick review in advance to meet the anticipated demand. Dry spells of long duration will reduce 60–70% of acreage monsoon-dependent Kharif crops, cattle fodder, and low water reservoir levels will induce a scarcity of drinking and irrigation water and the availability of vegetables, etc. Tea production has been reduced by 20–40% in Assam and Bengal due to temperature rises, as revealed by the Tea Research Association.