eBusiness Weekly
More heatwave days have been predicted this summer by the India Meteorological Department (IMD), with mercury already touching 38°C in several cities and is likely to cross 40°C soon.
IMD director general Mrutyunjay Mahapatra said most states will witness above-normal temperature from April to June.
Heatwave days are expected in different states against the four to eight days every summer. The intensity of heat is expected to be the highest in May-June, especially over Central India.
The warning comes at a time when the United Nation’s World Meteorological Organisation warned recently that 2024 will be see abnormal high temperatures after the world, including Asia and India, broke heat records last year.
India is “rapidly witnessing” numerous extreme weather events, Union minister Kiren Rjijju had said during a press conference.
“As there is [a] projection of extreme heat waves in the coming three months, all the stakeholders including the state governments have made elaborate preparations…”
What is a heatwave?
According to IMD, a heatwave occurs when the above-normal temperature is 4.5 higher than the long-term average temperature.
A paper released titled ‘Heat and Cold Waves in India: Processes and Predictability’ was published on April 26 last year by M Ravichandran, Secretary, Ministry of Earth Sciences, showed heat waves occur primarily in two regions — central and north-western India and coastal Andhra Pradesh.
The heatwave days were caused more during El Niño years as compared to La Nina. El Nino is associated with periods of warm weather caused by the El Niño–Southern Oscillation (ENSO), an oceanic and atmospheric phenomenon while La Nina is the cooler phase of the ENSO.
Onslaught of heat in India
Between 1961 and 2021, heatwaves increased in India by about 2.5 days due to global warming. The paper suggests given the frequency of rising heatwave in central and north-western India, there will be an upswing in two heatwaves and heatwaves by 12-18 days.
For instance, India recorded 280 heat wave days from March to May, 2022 — the highest in 12 years.
Five states namely Rajasthan, Madhya Pradesh, Himachal Pradesh, Gujarat and Haryana accounted for 54% of the heat waves in 2022.
India witnessed the warmest decade on record from 2014 to 2023, with the atmospheric carbon dioxide level reaching new heights of 425 ppm.
The country has observed a significant mean temperature increase of 0.15 degrees C per decade since 1950, according to a 2020 assessment by the MoES.
South India, which has experiences less heatwave compared to North and Central India, is likely to be affected by abnormal high temperatures in the coming years, the paper suggests.
Stress and heat stroke
Continued exposure to heat can lead to heat stress or heat-related illnesses from mild symptoms such as swelling, cramps, exhaustion, prickly heat to medical emergency like a heat stroke.
A fatal condition, heat stroke can stop brain to function due to uncontrolled body heating. Besides neurological impairment, increase in core body temperature (at least 40 degrees C), or hot, dry skin are other heat stroke symptoms.
External heat stroke occurs in young fit adults, hours after performing physical exercises or outdoor activities. While a classic slow heat stroke is deadlier, with individuals not able to regulate body temperatures.
This type of stroke is more common during heatwaves, and affects children, elderly and sick individuals.
Prediction for India
Last year in May, a report by an international team of climate scientists under the World Weather Attribution banner revealed that human-induced climate change made the April 2023 heat wave across India and Bangladesh 30 times more likely.
Humid heat wave of April 2023 could be the recurring event, as per the report, which also warned that India and Bangladesh could see more heatwaves every one or two years.
Scientists tracking developments in India said La Nina conditions settling in by June-August could mean better monsoon rains in 2024 compared to last year.
They said that El Niño has the adverse impacts on global climate in the second year of its development, that is, in year 2024.
Historical data indicates that past El Niño occurrences have predominantly resulted in diminished monsoon rainfall in India, which has been continuing since 2023 with less rainfall. This trend could lead to severe drought conditions and heightened temperatures.
Though the full impact of El Niño on Indian monsoon remains uncertain, significant heatwaves will be seen from February to June. This could potentially lead to extreme rainfall in southern India, and dry spells in north.
The rising impact of El Niño requires call for action from government, industries and individuals to actively engage in emission cuts, prioritise sustainable practices, use renewable resources and participate in energy conservation efforts. — News18
