From cold to hot to warm to drizzle and rainfall and then a full-fledged heatwave — that is how the past few weeks have been for Indians across the country as the climate has been consistently changing drastically.

While almost the entire country has been experiencing blazing heat over the past few days, parts of Madhya Pradesh, including Bhopal, witnessed thunderstorms, drizzle and lightning on Thursday morning. Mumbai, too, recorded its third hottest day of this month on April 19, with its temperature soaring to 38.8 degrees Celsius, just nearly a week after it recorded its highest rainfall in a single day in April.

A day earlier on April 18, more than 48 meteorological stations in the country recorded temperatures of more than 42 degrees Celsius. Of them, Odisha recorded the highest temperature of 44.2 degrees Celsius. The state preponed school summer vacations from Friday onwards. Even the 147-year-old Alipore Zoo in Kolkata has come up with water sprinklers, ice blocks, special diets to beat dehydration and bamboo sheds to keep its animals cool.

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The heatwaves are becoming more recurrent and lethal. Recently, 11 people in Navi Mumbai, Maharashtra, died of heat stroke as they stood under direct sunlight for hours while attending an award function where top government officials were present. This happened just two days after the state banned events from being held outdoors from 12 pm to 5 pm till the heatwave conditions abate.

In August last year, the Centre informed the Parliament that as many as 79 people had died because of heatwaves from April to June and more than 3,400 people reported illnesses because of the high temperatures during the period.

And now, a recent report from the University of Cambridge, UK, has stated that almost the entire country, barring around 10 percent of it, could severely be impacted by the abnormal rise in temperatures because of climate change.

The report states that heatwaves would adversely affect the productivity of people, their health and well-being as well as critically hamper the progress of the country towards its sustainable goals to a certain extent, that was not previously known or understood.

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The study analysed the recent heat index and the climate vulnerability index (CVI) of India using the record-breaking heatwave of last year as a case study.

More states, because of heatwaves, are now likely to be more at risk of extreme climate than the government's previous estimate, the report stated.

The report states that 90 percent of India, entire Delhi is in 'danger zone' of heatwave impacts.

“Heat waves are getting more intense in India, putting the country’s people in danger, which remains unaccounted for in its current climate vulnerability assessment. If this impact is not addressed immediately, India can slow its progress towards sustainable development goals. It is high time that climate experts and policymakers re-evaluate the metrics for assessing the country’s climate vulnerability,” the authors said in the report.

CVI assess India's climate vulnerability. The Department of Science and Technology devised this index, according to which around 20 percent of India is highly-vulnerable when it comes to climate change. However, the heat index puts 90 percent of the country in the danger zone, the report stated.

For example, states such as Haryana, Punjab, which witnessed temperature anomalies of around 6 to 7 degrees Celsius, which are usually classified "low" when it comes to climate vulnerability, but they face a higher risk because of heatwaves.

The India Meteorological Department has already said the country will witness above-normal maximum temperatures for most parts of the country from April to June. In 2023, India experienced its hottest February since record-keeping began in 1901. However, above-normal rainfall in March kept temperatures in check.

New agency PTI quoted a report by McKinsey Global Institute that has warned that if heatwave conditions continue, by 2030, India could lose between 2.5 percent and 4.5 percent of its Gross Domestic Product (GDP) per year.

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