Climate Change

Climate hazard: Heat-related deaths in elderly population to increase by 370% midcentury in a warming world

On average, 86 days of health-threatening high temperatures were experienced between 2018 and 2022

By Seema Prasad
Published: Thursday 16 November 2023
Photo: iStock__

If global mean temperature continues to rise to just under 2 degrees Celsius, annual heat-related deaths are projected to increase by 370 per cent by midcentury, assuming no substantial progress on adaptation, according to the 2023 report of the Lancet Countdown on Health and Climate Change.

At the current 10-year global average 1.14°C of heating, on average, there were 86 days of health-threatening high temperatures between 2018 and 2022, and 60 per cent of these temperatures were made more than twice as likely by human-caused climate change, the report added.

The hot weather has carried forward into the year 2023, which has recorded the hottest global temperatures in over 125,000 years and is so far the hottest year on record. Average planetary temperatures have been pushed to 1.3-1.4°C above pre-industrial levels, reported researchers at Climate Central, a climate news non-profit, earlier this year.

The sweltering heat compounds and exacerbates illnesses, leading to death. Some heat-related illnesses include dehydration, heat cramps and heat stroke. Certain chronic conditions including cardiovascular, respiratory and cerebrovascular disease and diabetes-related conditions can be worsened with even small shifts in temperature, the World Health Organization (WHO) explained.

High temperatures also increase the transmission of food and water-borne illnesses. It leads to increases in hospitalisation for respiratory diseases, diabetes mellitus, renal disease, stroke and mental health conditions, the WHO said.

People older than 65 years are particularly vulnerable to heat-related mortality and authors of the latest Lancet reported on the results of the simulations they performed on the health impact of extreme heat. 

According to them, annual heat-related mortality of people older than 65 years is projected to increase by 370 per cent above 1995–2014 levels by 2041–60 under a scenario compatible with limiting global temperature rise to 2°Celsius. 

The increase would be 433 per cent under a scenario in which no further mitigation occurs, assuming no further adaptation. 

By 2081–2100, these mortality levels are projected to increase by 683 per cent and 1,537 per cent for the two scenarios, respectively, the report added.

Besides the timing, intensity and duration of a heatwave event, the health impacts of rising temperatures depend on how acclimatised the local population is and the infrastructural support offered to brave the changing climate.

Closer home, according to Union Ministry of Health and Family Welfare data presented in the Lok Sabha in July, 264 people died in 2023 during the intense heatwave, recording the highest number of human casualties due to the phenomenon in the last five years.

Kerala reported 120 deaths, followed by Gujarat (35), Telangana (20) and Maharashtra (14), reported newspaper The Tribune.

However, this data was contradicted by other news reports. For instance, according to an estimate by the news agency Associated Press, hospitals and morgues were at capacity due to the heatwave experienced in June. In Uttar Pradesh, 119 people died from heat-related health issues, while 47 casualties were reported in Bihar.

The gaps in data can be supplemented by adequate research and analysis and the country appears to have fallen behind a little. 

In 2022, 127 scientific papers were published with lead authors based in India, a decrease from 2021's record 187 papers. Overall, there has been an 182 per cent increase in papers relating climate change and health (including adaptation, mitigation, and impacts) from 2012 to 2022, the Lancet report found.

Another point of consideration is attributing heatwaves as the cause of death. Deaths are seldom attributed to the heatwave itself, and the immediate cause of death, such as diabetes or heat strokes, is reported as the reason for hospital admission or death, Down To Earth previously reported.

According to a 2022 report by the International Federation of Red Cross and Red Crescent Societies, heat waves must be linked to health outcomes more conclusively.

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