The impact of on people 60 years or older has been “underestimated” a published in suggests.
Heat limits were evaluated in young (18–39 years), middle-aged (40–59 years), and older adults (60 years) to evaluate how impacts different age groups as the planet continues to warm up.
Health academics from Stanford University estimated that if the planet gets 1.5°C warmer, 22 per cent of the world’s older adult population will experience “frequent and widespread exceedance of heat-compensability limits,” which means their bodies will no longer be able to cool them down to compensate for extreme heat levels.
Currently, Earth’s 2025 average temperature sits at 2.14 degrees Fahrenheit (1.19°C), according to NASA. However, 2024’s temperatures (2.30 degrees Fahrenheit, 1.28°C) were “the warmest on record.”
“As the planet warms, understanding where, when, and to what extent environmental conditions will exceed human heat tolerance becomes crucial,” the study states.
“Intolerable heat will be experienced at much larger scales and for longer durations, affecting far more people than previously thought.”
India was found to have the largest population in the world exposed to at least 180 hours of “uncompensable heat stress” per year on average at 3°C warming, at 648.4 million people.
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“India, Pakistan, Bangladesh, Myanmar, and Niger warrant particular attention, exceeding both the absolute and proportional exposure thresholds,” the study states.
It was also found that at least 10 million older adults (at least 80 per cent of the older adult population) experiences 180 hours or more of “heat limit exceedance annually.”
In addition, older adults in south Asia and the Persian Gulf “could face sustained, day-and-night exposure for three consecutive months at 3°C or more warming.”
The study states that “the number of people aged 60 years and older is projected to double from one billion in 2020 to 2.1 billion in 2050, representing 21 per cent of the world’s population.”
Therefore, as the population continues to age, older adults will face “disproportionately severe and imminent risks” to their health.
The study also estimates that more than two-thirds of this population is “expected to reside in low-income and middle-income countries,” many of which “are also on the frontline of emerging uncompensable heat stress.”
“By overlooking the ageing population and heat vulnerability of older adults, previous projections based on limits for young adults might have seriously underestimated the frequency, geographical extent, and imminence of uncompensable heat stress with climate change.”
The 2025 report of the Lancet Countdown on Health and Climate Change, produced in collaboration with the World Health Organization (WHO) states that “the rate of heat-related mortality has increased 23 per cent since the 1990s, pushing total heat-related deaths to an average 546,000 deaths per year.”
“The average person was exposed to 16 days of dangerous heat in 2024 that would not have been expected without climate change, with infants and older adults facing a total of over 20 heatwave days per person, a fourfold increase over the last twenty years.”
Canada’s population is currently estimated to be 41,417,056 as of April 1, 2026, down 55,025 people from Jan. 1, according to Statistics Canada numbers from June.
March 2026 estimates state that the country’s population remains “well below the levels observed in the fourth quarters of 2023 and 2024.”
Statistics Canada also noted on Jan. 27 that the country’s population could soar to 76 million people, although that higher scenario estimate is down significantly from what the agency predicted last year.
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