Global Population Faces Increasing Extreme Heat Due to Climate Change
New study reveals an additional month of extreme heat for half the world’s population attributable to human-induced climate change.
A recent study has reported that approximately half of the global population experienced an additional month of extreme heat within the past year, compared to historical averages, as a consequence of human-induced climate change.
This finding, released ahead of World Action Day Against Heat on June 2, highlights the adverse health implications linked to continued fossil fuel use across all continents, particularly in developing countries.
The analysis was conducted by scientists from various research organizations, including World Weather Attribution, Climate Central, and the Red Cross Red Crescent Climate Centre.
The study specifically examined the period from May 1, 2024, to May 1, 2025, to assess the impacts of climate change on temperature extremes.
Extreme heat days were defined as those during which temperatures exceeded the 90th percentile of average historical temperatures recorded at specific locations between 1991 and 2020. The results demonstrated a significant increase in the number of extreme heat days, revealing that around four billion individuals, or 49% of the global population, experienced at least 30 more days of extreme heat than projected in a simulated world without human-caused climate change.
The study identified 67 extreme heat events throughout the year, each significantly influenced by climate change.
Notably, Aruba in the Caribbean recorded the highest incidence, with 187 days classified as extreme heat, which is 45 days more than what would be expected in a climate-stable scenario.
According to the data, 2024 marked the hottest year on record, surpassing 2023, with January 2025 also noted as the warmest January experienced to date.
Over a five-year span, global temperatures have risen by an average of 1.3 degrees Celsius compared to pre-industrial levels, with 2024 witnessing an increase that exceeded the symbolic threshold of 1.5 degrees Celsius set by the Paris Agreement on climate change.
The report further underscores a significant gap in data regarding health impacts related to heat exposure, particularly in poorer regions.
For instance, while Europe recorded over 61,000 heat-related deaths during the summer of 2022, there is a dearth of similar data from other parts of the world, resulting in many heat-related fatalities being misattributed to heart or respiratory diseases.
This finding, released ahead of World Action Day Against Heat on June 2, highlights the adverse health implications linked to continued fossil fuel use across all continents, particularly in developing countries.
The analysis was conducted by scientists from various research organizations, including World Weather Attribution, Climate Central, and the Red Cross Red Crescent Climate Centre.
The study specifically examined the period from May 1, 2024, to May 1, 2025, to assess the impacts of climate change on temperature extremes.
Extreme heat days were defined as those during which temperatures exceeded the 90th percentile of average historical temperatures recorded at specific locations between 1991 and 2020. The results demonstrated a significant increase in the number of extreme heat days, revealing that around four billion individuals, or 49% of the global population, experienced at least 30 more days of extreme heat than projected in a simulated world without human-caused climate change.
The study identified 67 extreme heat events throughout the year, each significantly influenced by climate change.
Notably, Aruba in the Caribbean recorded the highest incidence, with 187 days classified as extreme heat, which is 45 days more than what would be expected in a climate-stable scenario.
According to the data, 2024 marked the hottest year on record, surpassing 2023, with January 2025 also noted as the warmest January experienced to date.
Over a five-year span, global temperatures have risen by an average of 1.3 degrees Celsius compared to pre-industrial levels, with 2024 witnessing an increase that exceeded the symbolic threshold of 1.5 degrees Celsius set by the Paris Agreement on climate change.
The report further underscores a significant gap in data regarding health impacts related to heat exposure, particularly in poorer regions.
For instance, while Europe recorded over 61,000 heat-related deaths during the summer of 2022, there is a dearth of similar data from other parts of the world, resulting in many heat-related fatalities being misattributed to heart or respiratory diseases.
